Ryzen 3900X can't clock 1800MHz Infinity Fabric with 3600 CL14. Disappointed with Ryzen.

[Agent_D]

That's EXACTLY what I did. I finally gave up and settled for 3533 on RAM and 1767 on IF.
I decided to give it one last try and followed gerardfraser's instructions. It seems to be working so far and I'm currently stability testing my RAM overnight.

I'm thinking it may just be a limitation of my memory kit. It's a HyperX (samsung b-die) 32GB kit that is rated for 2666MHz @16-18-18-18-39 and getting 3533 at 16-21-21-21-41 seems to maybe just be its upper limit. I can run 1.35v with trfc of 480, and I can loosen the trfc some and even run it stable at 1.25v, but no matter how much voltage I give it (tried up to 1.5v), it's very stubborn with timings and doesn't like to run anything more than 16-18-18-18-39 at any speed except the stock 2666MHz. I settled at 16-21-21-21-41 because my latency and speeds don't increase at all by going to 16-18-18-18-39 and requires less voltage.

 

[KhakiKukhi]

I'm thinking it may just be a limitation of my memory kit. It's a HyperX (samsung b-die) 32GB kit that is rated for 2666MHz @16-18-18-18-39 and getting 3533 at 16-21-21-21-41 seems to maybe just be its upper limit. I can run 1.35v with trfc of 480, and I can loosen the trfc some and even run it stable at 1.25v, but no matter how much voltage I give it (tried up to 1.5v), it's very stubborn with timings and doesn't like to run anything more than 16-18-18-18-39 at any speed except the stock 2666MHz. I settled at 16-21-21-21-41 because my latency and speeds don't increase at all by going to 16-18-18-18-39 and requires less voltage.

I'm currently testing my sticks for stability at 3733 16-18-18-18-36 tRFC 653 1.48V.
It's not stable at 1.45V and lowering tRFC makes it even less stable. 1.48v seems to make it stable.
I'm having to feed a lot of voltage into my sticks and it's scaring me. I'm not sure if I should increase my 18s to 21s and lower the voltage.
My latency right now is about 67.4ns average between 10 AIDA64 benchmarks. I didn't see a latency increase going from tRFC 540 to 653 for some reason.

EDIT:
Changed 16-18-18-18-64 to 16-18-18-18-36. Was typo sorry.

 

[Agent_D]

I'm currently testing my sticks for stability at 3733 16-18-18-18-64 tRFC 653 1.48V.
It's not stable at 1.45V and lowering tRFC makes it even less stable. 1.48v seems to make it stable.
I'm having to feed a lot of voltage into my sticks and it's scaring me. I'm not sure if I should increase my 18s to 21s and lower the voltage.
My latency right now is about 67.4ns average between 10 AIDA64 benchmarks. I didn't see a latency increase going from tRFC 540 to 653 for some reason.

I would like to get my latency down, but I've not been able to get it below 71ns, it averages 73-77 in AIDA64.

 

[KhakiKukhi]

I would like to get my latency down, but I've not been able to get it below 71ns, it averages 73-77 in AIDA64.

Me too! I get about 77ns at 3600 CL16. Going to 3733 dropped it to 67.4ns. Strangely, going to 3800 with MCLK=UCLK=FCLK brings my latency to 97ns.
But I am feeding 1.48v which I'm not too comfortable with doing.

 

[TheLostSwede]

Never ending story: AMD Ryzen and "top" memory

It will take days/weeks to get it running and stable. You will test new BIOS, beta BIOS, rollback BIOS, you will learn 34 (or 39) options in BIOS, memory calculator, memory timing, sub timing, ..., you will wait for new, better Agesa. And again and again. Just AMD (ASUS) lab.

This is my old experience with top components, ASUS MB, Ryzen and RAM 3200 CL14. Never again. And now I see the same, 2,5 years later. Only Ryzen is now Ryzen 2 and memory 3600.

Ryzen (Ryzen 2) is good processor. I have one PC with X570 and waiting for 3950X. But forget to buy and use "top" memory for Ryzen. It is wasted time.

Not really, my RAM works fine at 3600 without any fiddling. Getting it to 3800 took a little bit of fiddling. Just doing fine tuning now. I have $89 RAM...
It's a huge improvement over my Ryzen 7 1700 system where initially I couldn't get the RAM over 2133.

 

[HTC]

Do we know for a fact that higher speed RAM actually causes performance loss due to the FCLK divider kicking in, other than latency measuring tools saying so? I think the "abnormal" cache size in 3rd gen Ryzen CPUs throws latency measuring tools off but dunno for sure.

One one hand, slower IF speed slows performance while faster memory improves it but the real question mark is the cache, and how it affects latency.

Any memory speed and latency sensitive program / game out there (cache) taxing enough to test this?

 

[TheLostSwede]

Once you go to uncoupled mode, yes, most software loses a bit of performance due to the lower speed of the IF.
Obviously this depends on the software, if you have something that likes really fast RAM, then you can still gain performance, but you seemingly need to hit 4400MHz on the RAM for most things to gain any performance. However, in most software it's within the margin of error imho.
Lab501 has a pretty good test that shows the difference going from 2800MHz to 4400MHz, although without 3800MHz.
@HTC Far Cry New Dawn at 4K at minimum FPS seems to be what you want...

AMD Ryzen 3000 – Part IV – DDR4 Scaling – ENGLISH Version

DDR4 Scaling PAGE GUIDE FOR THE MOBILE READERS 1 & 2 – Background info and news regarding the AMD Zen 2 memory sub-system 3 – Testbed 4 – 12 – CPU Tests 13 &#8211…

lab501.ro

 

[Chomiq]

Used DRAM Calc 1.6.2, it helped with passing memtest at 3600 and 3733. Below timings for 3733 @1.42V. 3466 CL14 still gives better result in CPU-Z bench. 520/54170 compared to like 525/55000.

3800 not booting might be the fault of F4j bios.

Nope. I give up. 3466 CL14 it is, at least for now.

 

[KhakiKukhi]

Used DRAM Calc 1.6.2, it helped with passing memtest at 3600 and 3733. Below timings for 3733 @1.42V. 3466 CL14 still gives better result in CPU-Z bench. 520/54170 compared to like 525/55000.

3800 not booting might be the fault of F4j bios.

3733 at 1.42v is stable for you? Wow, I had to crank that up to 1.48v myself for it to be stable.

 

[Chomiq]

3733 at 1.42v is stable for you? Wow, I had to crank that up to 1.48v myself for it to be stable.

Nah it wasn't. With very loose timings you can get it to work, but that's with 16-20-20-40-85.

 

[Cowboystrekk]

I'm currently testing my sticks for stability at 3733 16-18-18-18-64 tRFC 653 1.48V.
It's not stable at 1.45V and lowering tRFC makes it even less stable. 1.48v seems to make it stable.
I'm having to feed a lot of voltage into my sticks and it's scaring me. I'm not sure if I should increase my 18s to 21s and lower the voltage.
My latency right now is about 67.4ns average between 10 AIDA64 benchmarks. I didn't see a latency increase going from tRFC 540 to 653 for some reason.

I eould try 16-19-19-38 or 16-20-20-40. First timing affects performance a lot. Timing 2 to 4 does much less to performance, BUT especially no 2 affects stability a lot. Last value is often best kept at twice second value.

 

[KhakiKukhi]

I eould try 16-19-19-38 or 16-20-20-40. First timing affects performance a lot. Timing 2 to 4 does much less to performance, BUT especially no 2 affects stability a lot. Last value is often best kept at twice second value.

Thanks! I could try your suggestions later.
Right now, with the new DRAM calculator, I'm trying for 3800.
Any suggestions?

EDIT 1:
102.9ns latency lol.
mclk:fclk:uclk is 1:1:1

EDIT 2:
Went back to 3733, got this:

 

[HTC]

EDIT 2:
Went back to 3733, got this:
View attachment 131225

I'd stress test that to ensure stability and be done with it, if i were in your shoes.

 

[TheLostSwede]

Thanks! I could try your suggestions later.
Right now, with the new DRAM calculator, I'm trying for 3800.
Any suggestions?
View attachment 131222




EDIT 1:
102.9ns latency lol.
mclk:fclk:uclk is 1:1:1
View attachment 131224




EDIT 2:
Went back to 3733, got this:
View attachment 131225

Looks like 3733 is your sweet spot. The read speed looks very respectable.

 

[KhakiKukhi]

I'd stress test that to ensure stability and be done with it, if i were in your shoes.

Looks like 3733 is your sweet spot. The read speed looks very respectable.

Thanks! Seems like this is it then. I'm just gonna do some more stability testing and be done with it. Thanks for all the help and advice!

 

[TheLostSwede]

Thanks! Seems like this is it then. I'm just gonna do some more stability testing and be done with it. Thanks for all the help and advice!

Are you still disappointed?

 

[KhakiKukhi]

Are you still disappointed?

Initially, yes. I was not able to run stock BIOS + XMP without crashing. It took me almost 2 weeks to manually fine tune my timings. So I'm disappointed in out-of-box performance.

However, I'm currently really happy with my system right now. But I don't want to speak too soon, I have yet to do stability testing.

P.S. I'm not too sure about my CPU-Z bench scores.
CPU-Z after 5 runs:

Cinebench R20 which seems okay:

 

[TheLostSwede]

I wouldn't read too much into CPU-Z as a real benchmark. I've had it drop more than 100 points between runs on the multi-threaded test.
And in all fairness, AGESA 1.0.0.3ABB seems to be slower than some of the earlier AGESA's, so let's wait for 1.0.0.4 or whatever it will be (which seems to have been delayed) and the new AMD patch that's supposed to improve the boosting.

 

[KhakiKukhi]

I wouldn't read too much into CPU-Z as a real benchmark. I've had it drop more than 100 points between runs on the multi-threaded test.
And in all fairness, AGESA 1.0.0.3ABB seems to be slower than some of the earlier AGESA's, so let's wait for 1.0.0.4 or whatever it will (which seems to have been delayed) and the new AMD patch that's supposed to improve the boosting.

I'll take your advice, you know more than me!

 

[TheoneandonlyMrK]

I'll take your advice, you know more than me!

He is spot on , memory support has gotten much better with time , initially I couldn't get 3000 stable on an r2600x i ended up on 3466 c14 ,on the 3rd generation i can get 3600c14 stable but not 3800c16 i get an IF error on my boards diag point, im at 3733 c16 with high latency too like 67-70 so i might back off for now and join the waiting crew.

 

[KhakiKukhi]

He is spot on , memory support has gotten much better with time , initially I couldn't get 3000 stable on an r2600x i ended up on 3466 c14 ,on the 3rd generation i can get 3600c14 stable but not 3800c16 i get an IF error on my boards diag point, im at 3733 c16 with high latency too like 67-70 so i might back off for now and join the waiting crew.

Let me join you on the wait then.
I'm on 3733 C16 with high latencies too. 64 for my case.

One question, how did you get IF error on your board's diag point?

 

[TheoneandonlyMrK]

Let me join you on the wait then.
I'm on 3733 C16 with high latencies too. 64 for my case.

One question, how did you get IF error on your board's diag point?

Trying to get 3800 running, it wouldn't boot with IF beyond 1733 ,i didnt try the divider side of things at all though so it's possible i can go faster, at this point it's early days i won't give up, I didn't get it across well before but it's an evolving situation, has been the last year to be honest, chipping away at it.

I meant 1900 i can get 1800 IF not 1900 sorry.

 

[eidairaman1]

Initially, yes. I was not able to run stock BIOS + XMP without crashing. It took me almost 2 weeks to manually fine tune my timings. So I'm disappointed in out-of-box performance.

However, I'm currently really happy with my system right now. But I don't want to speak too soon, I have yet to do stability testing.

P.S. I'm not too sure about my CPU-Z bench scores.
CPU-Z after 5 runs:
View attachment 131228

Cinebench R20 which seems okay:
View attachment 131229

It was your choice of memory and lack of understanding of this platform

 

[TheLostSwede]

Some more information on the topic of memory and Ryzen 3000.
Knowing the memory ICs would've been helpful as well though...

Ryzen 3000 Memory Benchmark & Best RAM for Ryzen (fClock, uClock, & mClock) | GamersNexus

stub Memory speed on Ryzen has always been a hot subject, with AMD’s 1000 and 2000 series CPUs responding favorably to fast memory while at the same time having difficulty getting past 3200MHz in Gen1. The new Ryzen 3000 chips officially support memory speeds up to 3200MHz and can reliably run...

www.gamersnexus.net

 

[KhakiKukhi]

Some more information on the topic of memory and Ryzen 3000.
Knowing the memory ICs would've been helpful as well though...

Ryzen 3000 Memory Benchmark & Best RAM for Ryzen (fClock, uClock, & mClock) | GamersNexus

stub Memory speed on Ryzen has always been a hot subject, with AMD’s 1000 and 2000 series CPUs responding favorably to fast memory while at the same time having difficulty getting past 3200MHz in Gen1. The new Ryzen 3000 chips officially support memory speeds up to 3200MHz and can reliably run...

www.gamersnexus.net

Thanks for the link. I'll check it out.