# Intel i7-8700K Coffee Lake Memory Benchmark Analysis



## W1zzard (Oct 12, 2017)

We take a close look at memory speeds, latencies, and command rate on Intel's latest Core i7-8700K with Z370. Scenarios tested include fail-safe 2133 MHz, the platform default of 2666 MHz, and overclocked memory speeds ranging from 3000 MHz to 4000 MHz - at various timings.

*Show full review*


----------



## dcf-joe (Oct 12, 2017)

I want to thank you guys for taking the time to do these tests. I found this review very informative.


----------



## Gasaraki (Oct 12, 2017)

That's a lot of damn speeds and timings to test. Thanks.


----------



## EarthDog (Oct 12, 2017)

Wow... the LOE to do this was a lot!

Nice to see something we know already proven again with CFL. 

EDIT: Something really good to see would be CPU tests in games across multiple levels of cards at multiple resolutions.


----------



## Sasqui (Oct 12, 2017)

Awesome analysis.  Once again, this shows latency is just about as important as speed itself.


----------



## mouacyk (Oct 12, 2017)

Thanks so much for slogging through this review.  3.5% improvement at best, but I'll always tinker any way -- it's fun.


----------



## bug (Oct 12, 2017)

EarthDog said:


> Wow... the LOE to do this was a lot!
> 
> Nice to see something we know already proven again with CFL.
> 
> EDIT: Something really good to see would be CPU tests in games across multiple levels of cards at multiple resolutions.


You never really "know" when it comes to new platforms. We knew CFL hasn't changed the memory subsystem, so we suspected memory speeds won't matter much. Thanks to this article, now we have confirmation.


----------



## EarthDog (Oct 12, 2017)

I'm glad you are now in the know, bug.


----------



## bug (Oct 12, 2017)

EarthDog said:


> I'm glad you are now in the know, bug.


I'm happy to have made you glad, dawg


----------



## birdie (Oct 12, 2017)

So, basically anything above 2666 14-14-34-1T is useless (IOW, the price increase doesn't correspond with performance increase).


----------



## HD64G (Oct 12, 2017)

Great work @W1zzard! I hope the same test will be done for Ryzen 3,5,7 at least for 5 of the frequecies (2133, 2400, 2933, 3200, 3600). Forgive me if done already and forgot about.


----------



## W1zzard (Oct 12, 2017)

HD64G said:


> Great work @W1zzard! I hope the same test will be done for Ryzen 3,5,7 at least for 5 of the frequecies (2133, 2400, 2933, 3200, 3600). Forgive me if done already and forgot about.


https://www.techpowerup.com/reviews/AMD/Ryzen_Memory_Analysis/

No plans for another article, but we'll probably look at it again with AMD's next-gen, whenever that comes out.


----------



## hkpolice2 (Oct 12, 2017)

How about 5Ghz gaming tests /w the uncore maxed out on a GTX 1080Ti? I doubt the stock 4.3Ghz core & 3.7ghz uncore speed is enough to max out the memory @ 3600mhz+


----------



## BMfan80 (Oct 12, 2017)

Thank you for the analysis.

Sorry it's taken me sooo long to say thanx,even the hardware i don't care about is a good read here.


----------



## ORLY (Oct 12, 2017)

Civilization VI, F1 2017, Fallout 4, Far Cry Primal, Total War: Warhammer?
Would be cool to compare Coffee Lake to Ryzen where the frequencies [could] really matter for Ryzen.


----------



## Folterknecht (Oct 12, 2017)

Persoanlly I 'd be more interested in min FPS (min 1%) - that aside nice review!


----------



## Frick (Oct 12, 2017)

ORLY said:


> Civilization VI, F1 2017, Fallout 4, Far Cry Primal, Total War: Warhammer?
> Would be cool to compare Coffee Lake to Ryzen where the frequencies [could] really matter for Ryzen.



If you look at the Ryzen link wiz posted you see Ryzen gains about the same as Coffee Lake, ie slim. At least above 2666Mhz.


----------



## Ninjachopstixx (Oct 12, 2017)

Thanks for the great article guys, appreciate the hard work on all of your articles!


----------



## R-T-B (Oct 12, 2017)

Frick said:


> If you look at the Ryzen link wiz posted you see Ryzen gains about the same as Coffee Lake, ie slim. At least above 2666Mhz.



We now know however that ram clocks determine infinity fabric speeds, and as such, interthread communication benefits massively from higher speed ram on Ryzen, something not really covered in that review.


----------



## TheinsanegamerN (Oct 12, 2017)

Seems like low latency 3000 MHz memory would be the best bet, both from peak performance and the variety of choice available. I am curious what the raw bandwidth coffee lake gets from each set speed.



R-T-B said:


> We now know however that ram clocks determine infinity fabric speeds, and as such, interthread communication benefits massively from higher speed ram on Ryzen, something not really covered in that review.


Clearly it doesnt make that much difference. If it did, the multi core encoding benchmarks would have shown massive boosts from higher speed memory. Same with the compression and rendering benches. The performance improvements were in line with what coffee lake gains, suggesting that infinity fabric was not a bottleneck there.

I'm pretty sure AMD would have pushed the multiplier up if there was that much performance left on the floor.



hkpolice2 said:


> How about 5Ghz gaming tests /w the uncore maxed out on a GTX 1080Ti? I doubt the stock 4.3Ghz core & 3.7ghz uncore speed is enough to max out the memory @ 3600mhz+


Based on? Games have not been memory bandwidth limited for a very, very long time. DDR4 finally pushed the last holdouts, games like supreme commander, to their limits, and it is highly unlikely going from 4.3 to 5 GHz would significantly increase memory bandwidth demand to make the jump from 3000 to 3600Mhz memory noticeable. Going from 2666 to 3000 already shows practically no performance gain.

Game engines are simply not built to handle that much power. to benefit, you would need a game engine built to use that much bandwidth effectively, and such an engine would not work on consoles. Outside of perhaps cloud imperium, I cant imagine anybody modding a PC engine that much.


----------



## Manu_PT (Oct 12, 2017)

Altho I respect the reviewer for this immense work, the gaming benchmarks are flawed. Dishonored is well known for being limited and you can see it on 720p and 1080p tests where it has basically the same framerate. Hitman also isn´t the best game to bench CPU/RAM. Battlefield 1 and Witcher 3 on the other hand are useful. I would suggest you bench other intensive CPU games that are played on 144hz/240hz like Pubg and Quake Champions for example.

From the tests around the web, never a 3200mhz low latency kit would be on par with a 4000mhz CL19 one. Not when the GPU isn´t the bottleneck (aka with usage below 80%). E-sports players usually get the higher frequency ram kits to sustain better minimum fps. The gaming tests ended up confusing because 2 games shouldn´t be tested at all. And you should provide numbers about minimum fps/0,1%, wich are the most affected by increasing Ram Speed.


----------



## EarthDog (Oct 12, 2017)

TheinsanegamerN said:


> I'm pretty sure AMD would have pushed the multiplier up if there was that much performance left on the floor.


Dont hesitate to go look for testing on the web. 

It depends on testing, but there can be no to significant gains... here is an excerpt from the recent anand article in ryzen memory scaling..



> It is pretty clear to see that Ryzen can be fairly dependant on memory frequency, but it depends very much on the sort of test and the nature of the workload on memory accesses. On the benchmarks where it matters, our memory kit was above to push performance up and over 20%, although despite the few benchmarks where this happened, it was outnumbered by benchmarks that had zero or a very minor effect. Some gaming titles had up to a 5-10% difference in average frame rates, but others had zero change.





Manu_PT said:


> I would suggest you bench other intensive CPU games that are played on 144hz/240hz like Pubg and Quake Champions for example


testing online only games is a terrible idea....

Outside of that, i agree.


----------



## Sasqui (Oct 12, 2017)

Manu_PT said:


> Altho I respect the reviewer for this immense work, the gaming benchmarks are flawed. Dishonored is well known for being limited and you can see it on 720p and 1080p tests where it has basically the same framerate. Hitman also isn´t the best game to bench CPU/RAM. Battlefield 1 and Witcher 3 on the other hand are useful. I would suggest you bench other intensive CPU games that are played on 144hz/240hz like Pubg and Quake Champions for example.



Not saying you're wrong, just that the review is meant to cover a cross section of popular games, not just the ones that are really CPU bound.  I think that's fair and also shows which ones are and aren't.


----------



## R-T-B (Oct 12, 2017)

TheinsanegamerN said:


> Clearly it doesnt make that much difference. If it did, the multi core encoding benchmarks would have shown massive boosts from higher speed memory. Same with the compression and rendering benches. The performance improvements were in line with what coffee lake gains, suggesting that infinity fabric was not a bottleneck there.



Clearly?  Clearly you are accepting the results without thinking too in detail about them.  There's a reason W1zzard himself contradicts them in this very review.

Hint:  Encode doesn't use intercore communication much at all.

Other hint:  What does infinity fabric do?


----------



## Manu_PT (Oct 12, 2017)

Sasqui said:


> Not saying you're wrong, just that the review is meant to cover a cross section of popular games, not just the ones that are really CPU bound.  I think that's fair and also shows which ones are and aren't.



Fair enough, but we can´t conclude that higher frequency RAM isn´t worth for gaming. Depends on your usage, and again, minimumfps/0,1% are too important on a RAM Gaming test. Also you can´t get CAS 14 kits that easy, not at 3200mhz for sure. You can downclock 3800mhz CAS19 to 3200mhz CAS 14 tho, but that would cost the same money.


----------



## Sasqui (Oct 12, 2017)

Manu_PT said:


> Fair enough, but we can´t conclude that higher frequency RAM isn´t worth for gaming. Depends on your usage, and again, minimumfps/0,1% are too important on a RAM Gaming test. Also you can´t get CAS 14 kits that easy, not at 3200mhz for sure. You can downclock 3800mhz CAS19 to 3200mhz CAS 14 tho, but that would cost the same money.



I think in W1zzards conclusion he was saying in general there's a point of diminishing returns with really fast/expensive memory.  Lots of money with not much gain.  I didn't see any conclusion specifically about games per se .... but I guess you could read it that way.


----------



## Frick (Oct 12, 2017)

R-T-B said:


> Clearly?  Clearly you are accepting the results without thinking too in detail about them.  There's a reason W1zzard himself contradicts them in this very review.
> 
> Hint:  Encode doesn't use intercore communication much at all.
> 
> Other hint:  What does infinity fabric do?



So under what scenario and in what applications do you get the meaningful increase in performance with a faster interconnect? Honest question.


----------



## ZenZimZaliben (Oct 12, 2017)

Wow this is a great review. I just ordered 32GB G.Skill 3200 CAS 14 for my new build. Looks like it was a good choice.


----------



## Camm (Oct 13, 2017)

A very solid, informative article. Thanks for the work!


----------



## R-T-B (Oct 13, 2017)

Frick said:


> So under what scenario and in what applications do you get the meaningful increase in performance with a faster interconnect? Honest question.



Games and anything in which the threads must know what the other one is doing.


----------



## Frick (Oct 13, 2017)

R-T-B said:


> Games and anything in which the threads must know what the other one is doing.



But there's not much gain to be had, if you go for at least 2800Mhz.


----------



## R-T-B (Oct 13, 2017)

Frick said:


> But there's not much gain to be had, if you go for at least 2800Mhz.



True. Diminishing returns.  I was only saying it is greater than the Kaby/Coffee Lake Uncore's gains.

The real penalty is when you starve Ryzen of mem bandwidth, not saturate it.


----------



## Deleted member 172152 (Oct 13, 2017)

Coffeelake seems to care a lot less about memory than even previous Intel architectures. Strange.

I still think fast RAM is worth it if you have budget left after perfecting the rest of your build, even if it's only for peace of mind that when RAM IS a bottleneck, it won't bottleneck quite as much and of course bottlenecking tends to have exponentially decreasing performance, so even slightly better RAM could potentially make a fairly big difference.

Just don't go for 100 bucks more expensive RAM, but 20 or 30 bucks extra should get you a fair bit faster RAM.


----------



## noname00 (Oct 13, 2017)

I often just leave many applications opened, chrome has at least 50 tabs opened all the time. It would be interesting to see the performance impact of ram speed while having many apps run in parallel. For example gaming while encoding something with handbrake (using a single thread for that), listening to music from youtube using a browser with 40-60 tabs opened.

Thanks for the review


----------



## Melvis (Oct 13, 2017)

With those results been all over the place I would just go with the cheaper RAM, wouldnt waste your money on higher speed stuff.


----------



## Tsukiyomi91 (Oct 13, 2017)

This is a good review, @W1zzard. Very detailed & highly informative.


----------



## Tsukiyomi91 (Oct 13, 2017)

@Melvis it all depends on who will build it. I find the sweet spot between 2666MHz to 3866MHz. 3200 is a good place to start, though 2666 is more than enough for the mainstream user.


----------



## Melvis (Oct 13, 2017)

Tsukiyomi91 said:


> @Melvis it all depends on who will build it. I find the sweet spot between 2666MHz to 3866MHz. 3200 is a good place to start, though 2666 is more than enough for the mainstream user.



I agree, I wouldnt go the slowest stuff but wouldnt go the fastest ether, go with middle of the road like you said the 2666 or at most 3200, there is a way bigger difference when it comes to AMD Ryzen thats for sure.


----------



## Tsukiyomi91 (Oct 13, 2017)

Ryzen would benefit a much more higher speed kit, considering it's not really working in unison like Intel yet. Still a long way for Ryzen to be on equal grounds with a similarly built Intel system, but I know it has potential to be better.


----------



## THU31 (Oct 13, 2017)

The main thing that matters in gaming benchmarks is the minimum framerate. Memory bandwidth is most important in CPU intensive scenarios. You should watch some Digital Foundry videos where they compare memory speeds in various games. Watching the current framerate will show you just how big a difference it can make. Average framerate basically means nothing.


----------



## Dolfff (Oct 13, 2017)

Very usefull article, thank you so much. It shows very clearly that it doesn't make much sense to go extreme with memory on a stock clocked 8700k. 3200MHz with tight timing looks like the sweetspot for more demanding users.

However, I would really like to see this test repeated for a *8700k clocked at 5.2 GHz* (which seems a stable and useable oc for some 8700k's out there). That would in fact  be more realistic because I don't think many people are going to oc their memory only, without oc'ing there cpu. I assume that faster memory settings make more sense if CPU is overclocked. I would really like to see that confirmed (or busted) as to determine the "sweetspot" for such a setup. Meanwhile, can someone reflect on my assumption?


----------



## Manu_PT (Oct 14, 2017)

8700k clocked at 5,2ghz stable oc for most? I highly doubt that... some don´t get past 4,8ghz if you check the web.


----------



## R0H1T (Oct 14, 2017)

Dolfff said:


> Very usefull article, thank you so much. It shows very clearly that it doesn't make much sense to go extreme with memory on a stock clocked 8700k. 3200MHz with tight timing looks like the sweetspot for more demanding users.
> 
> However, I would really like to see this test repeated for a *8700k clocked at 5.2 GHz* (which seems a stable and useable oc for most 8700k's out there). That would in fact  be more realistic because I don't think many people are going to oc their memory only, without oc'ing there cpu. I assume that faster memory settings make more sense if CPU is overclocked. I would really like to see that confirmed (or busted) as to determine the "sweetspot" for such a setup. Meanwhile, can someone reflect on my assumption?


You'll need water cooling in many cases for that, a real good WC setup for some at that speed.
5.2 is a real outlier & hardly warrants a separate (re)bench though if you're doing a max OCing review or something, it makes sense.


----------



## TheHunter (Oct 14, 2017)

Thanks, was a interesting read.  I kinda expected bigger difference though.


I saw MT engine games (Resident evil series and lost planet2) can have big difference too, they're old now but still very cpu/memory/driver/dxapi dependent and can show difference quick. Ffxiv series also, crysis, x3tc..


----------



## Dolfff (Oct 14, 2017)

Manu_PT said:


> 8700k clocked at 5,2ghz stable oc for most? I highly doubt that... some don´t get past 4,8ghz if you check the web.


"Most" was indeed an exaggeration, sorry for that. I changed it to "some".


----------



## Dolfff (Oct 14, 2017)

R0H1T said:


> You'll need water cooling in many cases for that, a real good WC setup for some at that speed.
> 5.2 is a real outlier & hardly warrants a separate (re)bench though if you're doing a max OCing review or something, it makes sense.


Okay, 5.0 GHz then. Or 4.8. It's quite easy to do that without extreme measures (although an AIO WC is advised of course). This is not the point though. The point is that this is an unlocked processor that can very easily be overclocked (and many will do that) and it would be really interesting to see if advantages of faster memory are more visible in such a setup.


----------



## R0H1T (Oct 14, 2017)

Dolfff said:


> Okay, 5.0 GHz then. Or 4.8. It's quite easy to do that without extreme measures (although an AIO WC is advised of course). This is not the point though. The point is that this is an unlocked processor that can very easily be overclocked (and many will do that) and it would be really interesting to see if advantages of faster memory are more visible in such a setup.


Fair to say that I don't recall (m)any apps which are memory sensitive, even for games there are only a handful viz F1 *IIRC*. Outside of AVX512 intensive tests the Intel CPU have not been affected by memory, bandwidth or latency for instance.
Would be interesting to see if there are any AVX2 heavy tests which can show the effects of memory scaling or latency for KBL & CFL.


----------



## Prima.Vera (Oct 15, 2017)

birdie said:


> So, basically anything above 2666 14-14-34-1T is useless (IOW, the price increase doesn't correspond with performance increase).


I would say 3200Mhz is now the sweet spot, specially if you have tight timings.


----------



## EarthDog (Oct 15, 2017)

For intel...

...3200 is almost max for amd... some systems wont reach it..


----------



## efikkan (Oct 15, 2017)

DDR4-2666 is not going to bottleneck such systems without a very specialized workload. Just buy the most reasonable priced memory at >= 2666 MHz, and put the rest of the money in a GPU.


----------



## wurschti (Oct 16, 2017)

Great review thanks.
btw, I think the difference would be visible in scenarios where the CPU is lower, like the i5-8400 or so.


----------



## EarthDog (Oct 16, 2017)

Why would that be?


----------



## RejZoR (Oct 16, 2017)

So, things still haven't changed. 2666MHz is still the sweet spot. Anything above gives gains, but they are so small they aren't worth the ridiculous price jumps and stability issues. Where below 2666MHz, there are slightly more dramatic drops in performance.


----------



## Fluffmeister (Oct 16, 2017)

It's certainly good to see if I go Coffee Lake, I don't need expensive RAM to get the most out of it.

Cheap CPUs with expensive RAM don't compute.


----------



## RichF (Oct 18, 2017)

Prima.Vera said:


> I would say 3200Mhz is now the sweet spot, specially if you have tight timings.


It always has been, at least back before RAM prices became nutty.

One thing I'm wondering about, when people do RAM reviews, are the many arcane settings that motherboards typically automatically set at post. Unless the reviewer locks down all of those settings and adjusts them manually, the settings might change from boot to boot. And, boards will sometimes change the settings the reviewer puts in, automatically at post, if they compromise stability too much. This makes RAM benchmarking quite challenging and inaccurate for most reviews, which leave the handling of many timings to the motherboard ("training" at boot). If the sticks have XMP 2 profiles or whatever that work that's helpful but they're not always reliable, especially with Ryzen.


----------



## xorbe (Oct 18, 2017)

The results seem pretty straight forward:
1) avoid 2133
2) the avg diff between 2666 and 3466 is like 2-3%, save money and get the 2666 CL14
3) buy trident z rgb anyway


----------



## Valent117 (Oct 18, 2017)

hello
im planning for my next rig (z370 and 8700k)
should i buy 3600mhz cl 17 VS 2666hz cl 13? 16gb of each in dual channel, and both are >10ns latency
it will be mostly for gaming at 1440p 144fps
thx for help


----------



## xorbe (Oct 18, 2017)

Valent117 said:


> hello
> im planning for my next rig (z370 and 8700k)
> should i buy 3600mhz cl 17 VS 2666hz cl 13? 16gb of each in dual channel, and both are >10ns latency
> it will be mostly for gaming at 1440p 144fps
> thx for help



Is 2% more fps on average worth the cost delta?  Does the game you most play receive a notable boost?


----------



## W1zzard (Oct 18, 2017)

Valent117 said:


> hello
> im planning for my next rig (z370 and 8700k)
> should i buy 3600mhz cl 17 VS 2666hz cl 13? 16gb of each in dual channel, and both are >10ns latency
> it will be mostly for gaming at 1440p 144fps
> thx for help


Depends on the price of these options. If similar price then I think the 3600 CL17 should be a tiny bit faster, less than 1%


----------



## Valent117 (Oct 18, 2017)

xorbe said:


> Is 2% more fps on average worth the cost delta?  Does the game you most play receive a notable boost?





W1zzard said:


> Depends on the price of these options. If similar price then I think the 3600 CL17 should be a tiny bit faster, less than 1%



3600 is 20$ less expensive
games i play are not in the list, soooo


----------



## W1zzard (Oct 18, 2017)

3600 then or something slightly cheaper if you can use the leftover money To upgrade something else


----------



## David Fallaha (Oct 18, 2017)

TheinsanegamerN said:


> Seems like low latency 3000 MHz memory would be the best bet, both from peak performance and the variety of choice available. I am curious what the raw bandwidth coffee lake gets from each set speed.
> 
> 
> Clearly it doesnt make that much difference. If it did, the multi core encoding benchmarks would have shown massive boosts from higher speed memory. Same with the compression and rendering benches. The performance improvements were in line with what coffee lake gains, suggesting that infinity fabric was not a bottleneck there.
> ...



er there is defo a difference between 4.3ghz x6 and 5.2ghz x6 -provided there is a proper uncore overclock also

this is based on much experience overclocking x58 systems


----------



## Martin7 (Oct 18, 2017)

Hi,

I´m currently having issues to decide which ram speed I should choose for my new setup with i7-8700k. The "top-performer" of the test was the 3866 - before I saw the test I´ve ordered already 4000MHz Ram. My first intention/question was if its possible just do "downclock" the 4000 RAM with tighter timings compared to a similiar RAM. I guess I´m just getting the 3733 RAM, the price difference between 3200 up to 3866 isnt much, difference between 3866 and 4000 is already bigger...What do you think?


----------



## xorbe (Oct 18, 2017)

I don't think these new posters even read the attached article.


----------



## Martin7 (Oct 18, 2017)

That´s a big help indeed smartass. Furthermore, I´m just interested in the best configuration first, afterwards I still can change it based on price-performance. The biggest question first was for me if I should return the RAM which I´ve already bought or if I should keep it, downclock it to get maybe better timings or if I should just go for 3866 if I do care about 1 or 2%.


----------



## EarthDog (Oct 18, 2017)

The results arent pointing you in a particular direction already?

Honestly, the choice is yours, not ours. You have the data, know the price difference and level of effort, choose your poison. What is worth it to YOU?

Sure, its possible to slow them down and tighten timings...


----------



## mouacyk (Oct 23, 2017)

Price on DDR4 sucks anyway.  Worst time to build a system -- already spending at least double for DDR4 memory, where that amount could've gone to a better CPU or GPU.


----------



## R0H1T (Oct 23, 2017)

xorbe said:


> I don't think these new posters even read the attached article.


Just new 


mouacyk said:


> Price on DDR4 sucks anyway.  Worst time to build a system -- already spending at least double for DDR4 memory, where that amount could've gone to a better CPU or GPU.


Yeah I'm not upgrading till DDR4 prices come down to a reasonable level, as it is I overspent a bit on a laptop upgrade, don't want to feed the DRAM gold rush as well


----------



## W1zzard (Oct 23, 2017)

Martin7 said:


> if its possible just do "downclock" the 4000 RAM with tighter timings


that should be possible


----------



## xorbe (Oct 24, 2017)

R0H1T said:


> Just new



Touché!


----------



## alex310110 (Nov 8, 2017)

I really appreciate that you're using 720p resolution for CPU game tests to reduce GPU bottleneck. So I would like to ask a little more. Since game performance is contributed by both CPU and GPU, I suggest to adding another metric to display with each fps data you provided. This metric is the percentage when GPU usage is higher than 97% across the whole test process, which is to describe how much the test process is bottle-necked by GPU. I think this metric would help both CPU and GPU tests. Cheers.


----------



## Vayra86 (Nov 19, 2017)

With Coffee Lake, if you go in-depth on RAM speeds and latency for gaming, the sweet spot is somewhere around 3200mhz/cl16 or, if available, lower latency at the same price. Go higher speed and the avg and min fps results start going all over the place (from much higher, to even reduced performance in some titles). Go lower speed/higher latency, and you can see a steady loss in min.fps as you go down the ladder.

This review doesn't touch on that, but when you consider that for most rigs that get upgraded from Haswell onwards, the gain from a new CPU in gaming is 10-20% at best, a 3-5% performance gain from the RAM is in fact quite significant. Even from a performance/dollar perspective, relative to the old rig. More importantly, you get that performance where it matters most: in the minimums.

About the performance/dollar, we've already been in the situation for a few years now that we're looking at minimal boosts for high additional costs with platform upgrades. Its the nature of the beast. The top end performance is always the most expensive.


----------



## dasa (Nov 21, 2017)

First up nice review it does a good job of showing the effect of timings vs frequency even if it doesn't show the possible potential that is there with higher speed kits



Sasqui said:


> Not saying you're wrong, just that the review is meant to cover a cross section of popular games, not just the ones that are really CPU bound.  I think that's fair and also shows which ones are and aren't.


Im all for showing some games where ram makes next to no difference but a good ram review really needs some cpu bound open world games like pubg\arma\fallout to be fair not just games that show a small to no difference otherwise its a bit one sided

Its also good to see a few tests with the affect from a change in cpu clock speed so people know how much budget to allocate to improved cpu cooling for a few hundred mhz higher oc or to put it towards faster ram





Likewise the gains from improved gpu clock speed in games that are more gpu bound vs cpu\ram





as for comments of 8400 vs 8700k or stock vs a high oc for testing
a slower cpu like 8400 is more likely to show a bigger difference in a game that is partially gpu limited
but a overclocked 8700k will show a bigger difference in a cpu bound game as the faster the cpu the larger the % of its time that it spends waiting on files from ram if there not preloaded into its catch


----------



## Vayra86 (Nov 21, 2017)

This is the thing many people reading reviews and benchmarks miss - gains are usually highly situational. If you want to build a rig that does it all, you need to push all of its buttons.


----------



## dasa (Nov 23, 2017)

Installed the dishonored 2 demo and at 1280x720 ultra detail the first two levels were caped at 120fps or gpu limited when it dipped below with a GTX1070 at 2088MHz core 4700MHz mem and 6700k@4.6GHz
The third level I found a cpu limited section during the boat ride to shore
I deleted the start and end of the ride from where it hit the 120fps cap as including them artificially halved the % increase between the ram speeds

AVG FPS 
Overclocked 3733 16-16-16 =92.8 FPS 5.69% increase over 3200c14 or 22.7% increase over 2133c15
3200C14 XMP =87.8 FPS 16.1% increase over 2133
SPD 2133c15 =75.6 FPS


----------



## hasherr (Nov 29, 2017)

I am confused. In this review you claim "The minimum memory frequency we would recommend for a high-end Coffee Lake system is 2666 MHz. ". In AMD Ryzen Memory Analysis you said: "We are happy to report that you can save some money by choosing a slower DDR4-2133 or DDR4-2666 memory [..] You lose practically no performance to slower memory on the Ryzen platform". And in comment section here you claimed that Ryzen benefits from hi frequency ram because of Infinity Fabric being tied to DRAM frequency @ 0.5x. Lot of contradictions here.


----------



## cadaveca (Nov 30, 2017)

hasherr said:


> I am confused. In this review you claim "The minimum memory frequency we would recommend for a high-end Coffee Lake system is 2666 MHz. ". In AMD Ryzen Memory Analysis you said: "We are happy to report that you can save some money by choosing a slower DDR4-2133 or DDR4-2666 memory [..] You lose practically no performance to slower memory on the Ryzen platform". And in comment section here you claimed that Ryzen benefits from hi frequency ram because of Infinity Fabric being tied to DRAM frequency @ 0.5x. Lot of contradictions here.


Ryzen is weird on how it behaves depending on app because of its cache organization. Memory speed does help if your app uses it in a specific way, but sometimes the ratio between the memory divider and the infinity fabric makes the memory increase hurt, too. Then there are instances of the memory controller just being funky... for example, my Ryzen CPUs can do 3066 MHz memory divider without any problem, but struggles with 2933 MHz.

For guys like me that like to fiddle with memory, Ryzen is a lot of fun.


----------



## Mussels (Dec 12, 2017)

Anyone else find it ironic that the intel platform that handles high clocked memory well sees no real speed benefit, while ryzen with its ram OC difficulties sees a reasonable gain?


----------



## EarthDog (Dec 12, 2017)

Mussels said:


> Anyone else find it ironic that the intel platform that handles high clocked memory well sees no real speed benefit, while ryzen with its ram OC difficulties sees a reasonable gain?


If you know how it works it's not ironic at all.


----------



## John Naylor (Dec 23, 2017)

When deciding where we are going to go recommendation wise for RAM, (CAS / Frequency) × 1000 = X ns is used as an initial perfomance ranking comparison ... them look to see how it pans out.  The problem with most memory benchmark comparisons is that it is a ton or work.

 Most reviewers will pick 3 -5 games with a modeate GFX card, measure FPS and draw conclusions.  But performance is always limited by the weakest link and each game is limited by diffrerent constraints.    Some games are GPU Bound., some CPU bound and some (at 4k and above) VRAM bound.  If it's one of those Memory will have no impact above a certain point.  But when you widen the parameters, historically, things have changed.

a)  Start looking at min fps instead of average, and things can change
b)  Add a 2nd GFX card and things can change

Unfortunately, to widen the test parameters can triple the time investment ... fortunately every once and a while someone will take a few games known to have been impacted by memory speed (i.e. F1) and undertake the effort.  I haven't seen for DDR4 as yet so if anyone sees, plz advise.


----------



## Fabio (Jan 21, 2018)

Manu_PT said:


> 8700k clocked at 5,2ghz stable oc for most? I highly doubt that... some don´t get past 4,8ghz if you check the web.


mine reach 4.9 with a fairly quite low voltage of 1.26

we should re-do all test now with molten and spectre patch, imo, the whole situation could change a lot, expecialy timings wise...


----------



## EarthDog (Jan 21, 2018)

Fabio said:


> we should re-do all test now with molten and spectre patch, imo, the whole situation could change a lot, expecialy timings wise...


Retest overclocks? No.. it shouldnt matter at all.


----------



## Fabio (Jan 21, 2018)

EarthDog said:


> Retest overclocks? No.. it shouldnt matter at all.


lol no, i mean retest the impact of ram frequencies and latencies after patches


----------



## EarthDog (Jan 23, 2018)

I don't imagine it has anything to do with it... The issue isn't in RAM.


----------



## Fabio (Jan 23, 2018)

EarthDog said:


> I don't imagine it has anything to do with it... The issue isn't in RAM.


if a cpu have to constantly flush it s cache it also have to acces ram more ofte...  got it?


----------



## EarthDog (Jan 23, 2018)

It will be interesting to see the results and if it changes any. I'll bet not much...


----------



## mouacyk (Jan 30, 2018)

Fabio said:


> if a cpu have to constantly flush it s cache it also have to acces ram more ofte...  got it?


Not constantly, because since Westmere PCID was added.  PCID is why the impact isn't 30% across the board, as originally predicted and ended up being more like 5% maximum for modern Intel CPUs, excpet in IO-heavy workloads.


----------



## xorbe (Jun 12, 2018)

Thanks for this article.  Seriously, these types of reference articles should be pinned to the front page for current gen cpus.  Well I guess it kind of is, it's the 4th entry in the popular side bar.


----------



## Enterprise24 (Jul 9, 2018)

Try a quick test on Totalwar Attila 720p low to ensure that GPU will not bottleneck.
4133 17-17-17-37-350-2T vs 3600 14-14-14-34-278-1T both extremely tight sub timings and performance is no different (both 3 run avg = 265 fps) but 4133 get more bandwidth in AIDA64.
Also try 4133 17-17-17-37-350-2T auto sub vs tighten sub and performance different is around 6% (250 fps vs 265 fps).
Tested on 8700K @ 5Ghz / cache 4.8Ghz / 980 Ti OC


----------



## xorbe (Jul 9, 2018)

I observed that 2x16GB 3200 CL14 was better than 2x8GB 3600/4000 CL15/16. Guessing 16GB sticks keep more pages open or something like that.


----------



## cucker tarlson (Aug 7, 2018)

xorbe said:


> I observed that 2x16GB 3200 CL14 was better than 2x8GB 3600/4000 CL15/16. Guessing 16GB sticks keep more pages open or something like that.


it was probably due to single vs dual rank


----------



## jallenlabs (Oct 11, 2018)

Awesome write up.  So many benches!  As usual, unless you are benchmarking, higher speed memory just doesn't make sense.  Went with GSkill Trident 3000Mhz CAS 15 kit myself this time around.


----------



## Jo3yization (Nov 19, 2018)

Is something wrong with these benchmark results? How can the fps be so low and vastly different in the gaming section compared to tests done here(particularly for witcher 3), seems like theres a setting(maybe the CPU MCE disabled) coming into play?? https://www.eurogamer.net/articles/digitalfoundry-2017-intel-coffee-lake-core-i7-8700k-review_1

Appreciate the benchmarks, but if another site has benched on video & shows almost 30fps difference from 2133>3000, with much larger jumps between speeds, I think it should be addressed.
There are also a few youtube vids showing massive performance differences going from 2133>3000mhz, while these benchmarks show negligible gains at best.

















Could follow up gaming testing be made? It wouldn't need as many speeds ,just the common 2133/2400/3000 etc. with CPU intensive titles such as Battlefield 1, V, overwatch, Dota 2, CSGO, PUBG etc. It seems to make a pretty big difference on those titles.

Cheers!


----------



## W1zzard (Nov 19, 2018)

Jo3yization said:


> Is something wrong with these benchmark results? How can the fps be so low and vastly different in the gaming section compared to tests done here(particularly for witcher 3), seems like theres a setting(maybe the CPU MCE disabled) coming into play?? https://www.eurogamer.net/articles/digitalfoundry-2017-intel-coffee-lake-core-i7-8700k-review_1
> 
> Appreciate the benchmarks, but if another site has benched on video & shows almost 30fps difference from 2133>3000, with much larger jumps between speeds, I think it should be addressed. Cheers!


Different test scene, different graphics card, and they have hairworks turned off for witcher


----------



## Jo3yization (Nov 19, 2018)

W1zzard said:


> Different test scene, different graphics card, and they have hairworks turned off for witcher



Still, the titles used arent *that *popular and the fact

"_Multi-core optimizations, overclocking, and Turbo tweaks were disabled_" - Most of which are *enabled* by default, particularly turbo.
is definitely skewing the results & could easily lead a reader to believe ram speed makes a small difference. While some of the most popular titles are showing significant performance gaps, even /w the 7700k it made a big diff.  https://www.eurogamer.net/articles/digitalfoundry-2017-intel-kaby-lake-core-i7-7700k-review (make sure to scroll down to the memory tests). You can even see them running through a scene, how on earth did techspot find an area where the difference between 2133 & 4000 was <2fps across all speeds with no linear gains. To test that many speeds and not be comprehensive doesnt make sense.

It made a difference with a 6700k//GTX 1080 in battlefield 1 for another example, yet ZERO scaling or consistency results for TPU's BF1 tests. 

It even makes a difference with a 6700k(weaker) CPU & GTX 1080, but not a 8700k & GTX 1080?
https://www.gamersnexus.net/game-bench/2677-bf1-ram-benchmark-frequency-8gb-enough/page-2

But 8600k & 1080Ti?









Literally every test I've seen with 6700k>7700k>8700k or even i5 model CPUs & GTX 1060 or higher GPUs have shown *linear *performance scaling /w ram frequency, these are the only results I've found that show almost zero, in similar titles(BF1, Witcher 3).

Even with weaker configurations(which you'd logically think, less memory bandwidth requirement),, still linear scaling.

















And since I doubt a 8700k + gtx 1080 are immune to the negative effects, further investigation needs to be done, only the hitman results looked close to normal, (though they went overboard with _memory speeds. _BF1 & witcher performance *should* scale with ram speed in a linear fashion, just like other similar open world or large map titles.









The only logical explanation is the setup/lack of turbo/something else is affecting the memory results by a large amount,  which people should know or be mislead to think 2133 vs 3000 = 2fps.

The gaming benchmarks in particular, I think turbo off might be similar to doing CPU benchmarks @ 4k ultra, which masks the difference completely & why the 4000mhz ram is all over the place. If the CPU was running at it's stock turbo potential, I believe its enough to saturate DDR4 bandwidth when paired with a GTX 1080 in those titles, & we would see a much bigger difference & linear scaling with speeds as bandwidth improves between ram speed increment.


----------

