Question Ryzen RAM OC is successful but has no effect on performance

Mikewind Dale

Junior Member
Jan 11, 2017
10
1
16
Howdy y'all. I just successfully overclocked my RAM on a new Ryzen system, but it had no effect on performance. I thought this was odd, so I wanted to see how others reacted.

CPU: Ryzen 7 2700X
Motherboard: Gigabyte X470 Gaming 7 Wifi
RAM: 2x16 GB Kingston KSM26ES8/8ME (DDR4 2666 MHz ECC CL19 single-rank Micron E)

My understanding is that Ryzen greatly benefits from higher RAM clock speeds, even if the timings have to be much looser. So as a first pass, I used my motherboard's automatic overclock ("EZOT") to overclock the RAM for me. Surprisingly, higher RAM clocks had no effect on performance.

Benchmarks are:

Default: 2666 MHz, CL 19, tRCD 19, tRP 19, tRAS 43, tRC 62, CR 1T
Blender Blenchmark: 1:30
Cinebench R15: 175 single-thread, 1774 multi-thread
Corona 1.3: 2:04; 3,890,870 rays/sec
x265 0.1.4: 38.56s (29.25 fps); 38.52s (29.29 fps); 38.53s (29.27 fps); 38.53s (29.27 fps)

OC #1: 2933 MHz, CL 20, tRCD 21, tRP 21, tRAS 47, tRC 68, CR 1T
Blender Blenchmark: 1:30
Cinebench R15: 175 single-thread, 1740 multi-thread
Corona 1.3: 2:04; 3,906,290 rays.sec
x265 0.1.4: 37.55s (30.04 fps); 37.67s (29.94 fps); 37.60s (30.00 fps); 37.68s (29.93 fps)

OC #2: 3200 MHz, CL 20, tRCD 22, tRP 22, tRAS 52, tRC 74, CR 1T
Blender Blenchmark: forgot to run at this setting
Cinebench R15: 175 single-thread, 1785 multi-thread
Corona 1.3: 2:02; 3,963,260 rays/sec
x265 0.1.4: 37.79s (29.85 fps); 37.75s (29.88 fps); 37.48s (30.10 fps); 37.52s (30.06 fps)

The reason for the failure to achieve higher performance is not that that the RAM experiencing errors (which had to be corrected by the ECC, incurring a performance penalty). Windows Event Viewer logged no errors. I know that ECC is working because when I run "cmd /k wmic memphysical get memoryerrorcorrection" the output is "MemoryErrorCorrection 6", which indicates multi-bit ECC.

I did not stress-test these RAM settings to see if errors would have eventually occurred. So there's no guarantee that these settings were stable. But since no errors occurred in the time-frame in question, we know that errors weren't reducing performance.

Therefore, I found it very interesting that overclocking my RAM from stock 2666 MHz up to 2933 or 3200 had no effect on performance. From what I had read about the Ryzen, I thought overclocking the RAM would increase overall performance by at least a single-digit percent.

Could it be that the timings are too loose? Still, the timings at higher clock speeds aren't so much looser than stock, and I'd be surprised if such small increases in timings could entirely negate the benefits of a boost in clock speed.

I'm curious if anything has any thoughts or insights. Thanks.
 

VirtualLarry

Lifer
Aug 25, 2001
48,372
5,092
126
3200 CL 20, on ECC memory? That's kind of fail for performance. Performance RAM (non-ECC Gskill TridentZ or the like - Samsung B-die) is 3200 CAS 14.

Ryzen is also quite latency-sensitive, so increasing the latency while increasing the clock speed, is probably kind of a wash, for most things.

I noticed that you were only testing rendering and video-encoding. Most of the discussion of Ryzen memory clocks, has been around gaming.
 

Mikewind Dale

Junior Member
Jan 11, 2017
10
1
16
Okay, thanks. I'll go back and try it on 3DMark.

As for the latency: I just tried to adjust the latency, but the latency settings are all greyed out in the BIOS even when I set memory timings to manual. I'm checking my motherboard manual, and all it says is that "Memory Timing Mode" has to be set to "Manual." But when I do that, all the memory timings are still greyed out. So I'm not sure what's going on there. If I can't figure out how to manually set the memory timings, then they will be whatever they will be.

By the way, I'm looking at DDR4 3200 MHz on Newegg, and everything I see - including G-Skill TridentZ - is CAS 16.
 

Dasa2

Senior member
Nov 22, 2014
245
29
91
Video editing sees no gain from RAM speed but photo editing does.
3dmark timespy physics sees a moderate improvement but still only around half what some games may experience.
Most other 3dmark tests see no benefit from RAM speed.

Any of these kits are considered good overclockers and will typically do 3466c14 on Ryzen 2 with a good MB and a bit of work.
https://www.newegg.com/Product/ProductList.aspx?Submit=ENE&IsNodeId=1&N=100203071 600561668 600546709

There is some handy info here on overclocking RAM.
https://www.overclock.net/forum/10-amd-cpus/1628751-official-amd-ryzen-ddr4-24-7-memory-stability-thread.html

Here is a gigabyte X470 oc guide maybe it will have some useful info on how to change timings in its BIOS.
https://overclocking.guide/gigabyte-x470-overclocking-guide/
 
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Mikewind Dale

Junior Member
Jan 11, 2017
10
1
16
VirtualLarry and Dasa2, thanks.

So I managed to adjust the timings in RyzenMaster. But even after lowering all my latencies (not just CAS) by a few ticks, my 3DMark scores (both aggregate and the physics score alone) only went up by a fraction of one percent. So I'm going to say it's not worth the effort.
 
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DrMrLordX

Lifer
Apr 27, 2000
16,009
4,962
136
3DMark doesn't show many gains in scores from RAM. What @VirtualLarry is talking about is raising minfps in some games/gaming benchmarks.

If you really want to see a difference, try SuperPi Mod 1.5 xs or y-cruncher. I find both to be very sensitive to overall memory performance. You should also see improvements in intercore latency testing in SiSoft Sandra at higher memory clocks regardless of your timings.
 

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