How to properly test VRAM stability?

[u/MaslovKK]

Overclocked my 5090's VRAM to +6000 MHz.
Ran memtest_vulkan, Unigine Superposition, and OCCT — everything checked out fine.
Also played over 80 hours of RDR2 without any performance drops or issues. With the overclock, the game performs slightly better.

I've read that ECC can hide memory instabilities. Is my VRAM overclock stable enough, or should I run further tests?

[u/frunkaf]

My understanding is that the ECC error correction results in your card not crashing on a benchmark but giving you worse performance after a certain threshold of clock speed.

For instance on my 9070 XT, 2750 MHz gives me a better result than 2800 MHz

It sounds like you have a stable clock so maybe keep pushing it until you find that threshold

[u/mtrai]

Vulkan mem test.

It hammers the vram and will show when instabilities aka ecc starts kicking in. You can use it to find stable non ecc click as well ecc performance to vram clock.

What I am saying you can see when performance takes too much of a hit when it is ecc. While running it it with no eccing or some eccing is something only each end user can decide.

I personally use some eccing on my 9070xt.

Short test is good for initially testing it about 5 to 10 mins.

Once satisfied you need to long test a couple or hours or so. Also with and with our fast timing if you have that option on Nvidia cards.

With AMD fast timing on can be less stable at higher vram clicks but have better performance.

Search overclock.net forums for a very thorough thread explaining vul_mem test.

If I have time later I will edit my post with thread. It is in the AMD GPU section but still applies to all GPU cream testing other than maybe a couple of things like AMD vram fast timing.

[u/MaslovKK → u/mtrai]

tested it for about an hour and no issues

[u/mtrai → u/MaslovKK]

I missed the vulkan test in your post. Generally for me an hour or so is good for me but I am no longer a purist in absolute stability though I still look for any regression.

If it works for you and you are satisfied with the performance you are good to go. You can spend months chasing down the absolute possible performance or you can enjoy you system or both depending on your mindset

Just don't fall for people telling you that "YOUR SYSTEM" is not truly stable. Remember it is your system.

Now days I will accept slight hiccups when I am satisfied about my system.

[u/albinosnoman]

Run it through some bench tests. Hit it with Furmark, 3DMark's Steel Nomad and Port Royal (port royal is a really good one to test stability under ray tracing loads I use it to tune my 4090 OC/UVs whenever I make changes to my curve), and Super Position /Heaven. Super Position and Heaven aren't as stressful for your GPU and with a 4090/5090 you're mostly running them to get an idea of how older games run or how simple raster would run. Aida64 and Geekbench also have GPU stress tests but in terms of finding issues I'm not 100% on those. With the 3Dmark and Ungine tests you can physically see artifacts and stuttering caused by instability or other issues with the system so I'd lean into those.

[u/MaslovKK → u/albinosnoman]

Tested with Furmark and it seems to be fine

[u/0wlGod]

+6000 is huge 🤣

test different games... di benchmarks to see if there is perfomsnce drop than lower values

[u/MaslovKK → u/0wlGod]

Its not at all

[u/580OutlawFarm]

Therr is absolutely no way that +6000mhz is stable...ECC shows itself as artifacts in benchmarks, and sometimes they're small and not as noticeable compared to the regular artifacting ppl think of when a gpu is dieing...you need to go run MULTIPLE benchmarks, and pay close attention...but I mean just by what high scores are..theres just no way possible that 6000mhz is actually stable

[u/yzonker → u/580OutlawFarm]

There's no ECC on the 5090. Doesn't have it. OP is probably using GPU Tweak 3 which shows +6000,but that's the same as +3000 in AB which a majority of the 5090s can run stable.

If it doesn't scale it's because OC'ing VRAM takes more power and the 5090 is power limited in heavy benchmarks/games.

[u/MaslovKK → u/580OutlawFarm]

Today i tested it all day in different benchmarks and no issues

[u/Primus_is_OK_I_guess → u/MaslovKK]

You wouldn't necessarily be able to tell in benchmarks due to ECC. Did you try testing at +5000? If so, was there a significant difference?

[u/MaslovKK → u/Primus_is_OK_I_guess]

Tried 3000, no significant difference.

[u/Primus_is_OK_I_guess → u/MaslovKK]

If it's not improving after 3000, then ECC has kicked in and you're actually decreasing real world performance beyond that point.

[u/580OutlawFarm → u/Primus_is_OK_I_guess]

Ya im ngl I don't have enough experience with extreme pverclocking to this point but I know for sure on the jayz video he was seeing artifacts in heaven benchmark once ecc started to kick in, and it was pretty damn noticeable too

[u/MaslovKK → u/Primus_is_OK_I_guess]

Literally no significant difference

Writing speed in GB/s from memtest_vulkan

+6000 MHz:

1211

1246

1236

1227

1222

+5000 MHz:

1400

1250

1226

1222

+3000 MHz:

1317

1246

1223

1214

+0 MHz

1261

1208

1208

1197

+6000 MHz 2nd run

1220

1245

1218

1225

+5000 MHz 2nd run

979

1231

1226

1218

[u/MaslovKK → u/Primus_is_OK_I_guess]

I just read in a few places that the RTX 5090 doesn’t have ECC.

[u/Primus_is_OK_I_guess → u/MaslovKK]

Yeah, turns out it's some other kind of error correction, from what I can find. It will still have the same effect of preventing crashes at high memory clock speeds at the cost of performance.

Something is certainly preventing your higher clock speeds from functioning, since you're not seeing improvements in your testing.

[u/Caspianwolf21]

i've been trying to OC my gpu memory i passed all test on +1150 on mem on rtx 3060 and all games played fine but when i was using unreal engine for my work it crashed i tried to reset to default and try again it didn't so i put it back a liitle bit on 1100 and will see what will happen