AMD Ryzen 9 9950X3D Carries 3D V-Cache on a Single CCD, 5.6 GHz Clock Speed, and 170 Watt TDP

[Wirko]

Zen 5 makes it possible to stack more than one cache chip under the CCD. But if (*IF*) that's going to happen, it will be in Threadripper or Epyc CPUs.

Yeah, thanks for pointing out!

I guess @9550pro caused some interference in your thought process.

 

[lexluthermiester]

Zen 5 makes it possible to stack more than one cache chip under the CCD. But if (*IF*) that's going to happen, it will be in Threadripper or Epyc CPUs.

And that is why the 9900X3D & 9950X3D will never be that great, the 3D Cache is not evenly distributed, and it's supposed to be.

 

[Visible Noise]

Someone really needs to do a performance per square mm (factoring in just the core size) to figure out how efficient Intel's big little is as compared to AMD. Should probably do one for AMD's dense cores as well.

As a consumer how is this relevant? When you shop for a car do you calculate performance per square inch of cylinder bore?

 

[redzo]

While there might be some product policy considerations, I think that technical hurdles are still a thing. As far as product policy, it might not be so much no competition from Intel but the fact that AMD wants to sell dual 3D cache Threadrippers. Who would buy a pro platform if you can have the same on a much cheaper consumer platform? Right. No one. That is probably the main reason why AMD is keeping dual 3D Cache Threadripper (and above) exclusive.

The technical hurdles for gaming (as opposed to the professional stuff with the Threadrippers) are not to be underestimated, however. Inter CCD latencies are still a thing and you would have to make sure that the scheduler always "fills up" a single CCD first (eight cores) before switching to the second CCD if more cores are needed (which will be the case in less than 1% of games btw).

AMD is doing the right thing here imo. A dual cache 99xx CPU would be very expensive and the real world returns would be minimal or even detrimental, depending on the game. The most critical factor for gaming is inter CCD latencies and you can only mitigate those latencies to a minor extent by having cache on both CCDs. You would still want any game to utilize only a single CCD for as long as possible before spilling over onto CCD #2.
The challenges with regard to scheduling would, in fact, become even more difficult. With 7950X3D it is "easy" because the 2nd CCD is simply put to sleep (core parking) but if you had dual cache on a 9950X3D, well, wow... that would open an all new palette of cans of worms when it comes to scheduling .

Games remain thread-limited. You can't just throw more cores at the problem and hope that all tasks are automagically split up between the cores. That's not how it works. Multithreading is very complex and most of the time other threads are waiting for one thread to finish their work.

Anyone who believes that they need more cores for gaming (should be very few people as only very few games effectively utilize more than four to six cores) is better off waiting for AMD to put more cores onto their CCDs. We'll have to wait and see if they will go straight from 8 to 16 or if there will be an intermediary step but for gaming that is the (our) ticket to success.
Dual CCDs will always remain a compromise for a home/gaming plus light productivity setup. Anyone with serious needs will go Threadripper/EPYC and anyone who is just gaming will always be better off with a single CCD CPU (9800X3D/7800X3D at the high end especially).

I think we are losing ourselves in optimizations, efficiencies and not getting the bigger picture.
We already have two identical non cache CCD's that work fine together. They(amd) already have the recipe for this. One CCD with cache already works damn good. They can manufacture a dual cache dual CCD in the same way as they are doing a dual CCD non cache one. They already master this.

But the devil is in de details: manufacture. They literally have to increase the cost by physically adding a second cache die.
I will actually pay more for a dual cache dual CCD. What I will get in return is no more shenanigans regarding the way threads are spread across the entire CPU. This will just work as the simple dual CCD no cache product.

But what does this mean for AMD? They have 0 incentives to do this. The software cost solution for a single cache CPU dual CCD is almost zero compared the hardware one of actually manufacturing and adding a second cache die.

In the end, this is a simple cost reduction business decision from their behalf that has nothing to do with the technicalities of the more desirable dual cache end product.
I think they already have the product, but they simply choose not to release it.

 

[evernessince]

As a consumer how is this relevant? When you shop for a car do you calculate performance per square inch of cylinder bore?

It's not relevant to consumers, it's relevant to enthusiasts. I assume you are not the latter. If you are not interested in the topic, you can kindly avoid butting in. Thank you

 

[kapone32]

170 Watts? These could be some seriously fast CPUs or not. That is much more than the 7900X3D pulls.

 

[Visible Noise]

It's not relevant to consumers, it's relevant to enthusiasts. I assume you are not the latter. If you are not interested in the topic, you can kindly avoid butting in. Thank you

Serious question, why should even “enthusiasts” care? Do you buy your CPUs by the mm?

 

[Chaitanya]

boring af, well, here is waiting for the next generation

Hopefully there would be symmetric ThreadRippers this time around with X3D cache(though I suspect they will be eye wateringly expensive).

 

[AusWolf]

Sigh.... Still with the assymentric cache arrangement....

Yep. I'm staying away from any CPU that relies on software to run properly, that's for sure.

 

[Onasi]

There were rumors that this go around AMD would go for a symmetrical arrangement. Guess not. This pretty much confirms that the 9800X3D will be the gaming champ for quite a while. Well, until Zen 6 at least, if not Zen 6 X3D. I am not too hopeful on Intel pulling a rabbit out of a hat on the next generation.

 

[Neo_Morpheus]

I recall reading that their own internal testing showed that there was no real gains in adding 3d cache to both ccd.

I also wonder, how much money are these companies making out of gamers?

Because us being the most vocal doesnt mean our purchase justify the r&d and other expenses.

And since the AMD name seems to only (or mostly) bring hostility from consumers (even on this cpu related article, the trashing is hot and heavy) then adds to the question, its worth for them to continue?

 

[DTheSleepless]

I love how redzo totally cleanly, neatly, perfectly explains why 3D V-Cache on the second CCD would not only NOT generate performance improvements but potentially be *worse* than the current implementation for gaming, and then the other armchair engineers basically "nu uuuuuuhhh" them.

It's faster and lower latency to run everything off a single CCD with one V-Cache, the instant the game has to hop off that CCD you're incurring latency penalties. Even on non-X3D parts, the scheduler tries to keep games to one CCD. AMD has experience keeping the scheduler running things where they'll be fastest. Do you remember the Ryzen 3 3300X and 3100? On Zen 2, Core Complexes (CCX) were 4-core instead of 8-core (like on Zen 3 onward). So the 3100 was massively slower than 3300X because even though the two CCX's were on a single die, 3300X was 4+0 (all cores in one CCX) and 3100 was 2+2.

See: AnandTech's Zen 4 Review, Core-to-Core Latency

The instant you have to go off-die to the other CCD your latency quadruples, this is a fact of Infinity Fabric. You have effectively lost the latency benefit X3D gives you.

Back when AMD announced the 5800X3D people asked them why they didn't do a 5950X3D, and then when they finally did the 7950X3D and 7900X3D, they were worse for gaming than the 7800X3D and had scheduler issues.

This is why.

 

[Visible Noise]

Yep. I'm staying away from any CPU that relies on software to run properly, that's for sure.

Going back to a 8088? Because anything after that requires software to run properly, unless you’re running a 30 year old OS. Your 7800X3D thinks it’s a 16bit cpu running in a 20bit address space until software sets up the correct environment and switches it to long mode.

 

[AusWolf]

Going back to a 8088? Because anything after that requires software to run properly, unless you’re running a 30 year old OS. Your 7800X3D thinks it’s a 16bit cpu running in a 20bit address space until software sets up the correct environment and switches it to long mode.

Sure, pick apart everything I said, it'll make you look very clever indeed...

I don't want to install and configure any software other than the OS to run my CPU properly. Better?

 

[Onasi]

@AusWolf
Hurrrrrrr, TEKNIKALLY, the XBox app and GameBar are a part of a default Windows installation, so checkmate atheists!

No, but really, I think everyone knows that the dual CCD X3D chips are clunky and mostly not worth messing around with. That’s the same energy as people recommending using Process Lasso for Intel CPUs to bypass E-cores. Like, yeah, that do be working, but… I don’t wanna.

 

[AusWolf]

@AusWolf
Hurrrrrrr, TEKNIKALLY, the XBox app and GameBar are a part of a default Windows installation, so checkmate atheists!

Well, TEKNIKALLY, I'm on Linux, and even when I was on Windows, I had both the game bar and the Xbox app disabled, so it's not checkmate after all.

No, but really, I think everyone knows that the dual CCD X3D chips are clunky and mostly not worth messing around with. That’s the same energy as people recommending using Process Lasso for Intel CPUs to bypass E-cores. Like, yeah, that do be working, but… I don’t wanna.

I agree. I try to arrange everything in my life (my PC included) around the ethos of KISS.

Not to mention, if you're a gamer, a 9800X3D will do fine. If gaming is a secondary consideration, the 9950X will give you the oomph you need while still not being half bad in gaming. Being a hardcore gamer who needs the cache for the last FPS drop and also needing 16 cores at the same time is kind of a no man's land, imo.

 

[Marcus L]

Imagine consistently releasing the fastest gaming CPU's for the last few gens and getting flack from nobodies on random tech forums, cause ergh no dual x3D CCD, ergh now 170w and not efficient, people won't be happy until AMD release x3D with 6GHZ clock speeds at 75w TDP and 200% better performance than anything Intel can bring, these are the best gaming CPU's in the world right now

 

[AusWolf]

Imagine consistently releasing the fastest gaming CPU's for the last few gens and getting flack from nobodies on random tech forums, cause ergh no dual x3D CCD, ergh now 170w and not efficient, people won't be happy until AMD release x3D with 6GHZ clock speeds at 75w TDP and 200% better performance than anything Intel can bring, these are the best gaming CPU's in the world right now

I'm not saying that these CPUs aren't great, just that they're kind of pointless. Gamers have the 9800X3D. Professionals have the 9950X. Who is the 9950X3D made for exactly? Professionals who also need the last drop of FPS while they're gaming? C'mon...

 

[Legacy-ZA]

Imagine consistently releasing the fastest gaming CPU's for the last few gens and getting flack from nobodies on random tech forums, cause ergh no dual x3D CCD, ergh now 170w and not efficient, people won't be happy until AMD release x3D with 6GHZ clock speeds at 75w TDP and 200% better performance than anything Intel can bring, these are the best gaming CPU's in the world right now

Even if AMD did, they would still find something to complain about.

 

[AusWolf]

I recall reading that their own internal testing showed that there was no real gains in adding 3d cache to both ccd.

I also wonder, how much money are these companies making out of gamers?

Because us being the most vocal doesnt mean our purchase justify the r&d and other expenses.

And since the AMD name seems to only (or mostly) bring hostility from consumers (even on this cpu related article, the trashing is hot and heavy) then adds to the question, its worth for them to continue?

Personally, I wouldn't bother with dual CCD X3D CPUs at all. Single CCD X3D is great for gamers, dual CCD non-X3D is good for professionals (and for a bit of gaming, too), but the overlap between these two types of people is way too thin.

 

[john_]

FYI Zen 5 performs better in games with SMT off, so I wouldn't be so quick to criticise Intel for being ahead of the curve.

I am just saying that staying with only 8 P cores while removing Hyper Threading looks like a step backwards. While I think that AMD will keep their SMT, Intel needs to increase their P cores on their mainstream CPUs to at least 10 if not 12. With TSMC's manufacturing or a working 18A, they have enough room to increase P cores. The question is, are they going to do it or increase E cores again for a higher marketing advantage in the eyes of the average consumer who only reads total number of cores?

 

[dgianstefani]

I am just saying that staying with only 8 P cores while removing Hyper Threading looks like a step backwards. While I think that AMD will keep their SMT, Intel needs to increase their P cores on their mainstream CPUs to at least 10 if not 12. With TSMC's manufacturing or a working 18A, they have enough room to increase P cores. The question is, are they going to do it or increase E cores again for a higher marketing advantage in the eyes of the average consumer who only reads total number of cores?

For what purpose? You are saying that Intel "needs" to do these things, but games don't benefit, nor do MT workloads. It makes more sense for MT to add more E cores, and makes more sense for gaming to have fewer faster cores. You're talking about the "average consumer who only reads total number of cores", then essentially doing the same thing.

 

[Broken Processor]

Single CCD with 3D cache not interested simple as that.

 

[csendesmark]

Can't wait to see it in action!

 

[john_]

Imagine consistently releasing the fastest gaming CPU's for the last few gens and getting flack from nobodies on random

It's AMD. It means to be this way.
When 5800X3D came out people wanted a 16 core with 3D cache. AMD gave them two, they didn't liked them because in gaming they where some times somewhat slower than the 8 core part. Now they want each CCD to have it's own 3D cache. AMD will give them this, but they might see that in some cases performance is still lower than the 8 core part, because - don't know - maybe data gets on 3D cache 1 while the CPU core trying to access it is in CCD 2 or something introducing latency. Then they will be asking for a unified 3D Cache under both CCDs and ..... that will never end.

For what purpose? You are saying that Intel "needs" to do these things, but games don't benefit, nor do MT workloads. It makes more sense for MT to add more E cores, and makes more sense for gaming to have fewer faster cores. You're talking about the "average consumer who only reads total number of cores", then essentially doing the same thing.

Don't know. Progress maybe? Gaming is probably already past 8 threads on P cores and maybe that's why Intel's latest CPUs perform so poorly in some games.