cancel
Showing results for 
Search instead for 
Did you mean: 

Realbench - Instability Detected

joppiano
Level 7
Hi gurus.

I used to have stable 5GHz overclock, but after 10 months (ish) I started to experience instability.
I decided to update BIOS since there was 4 new versions available, and then I could also start over on my overclock.

Did some quick p95 small ffts to check for thermals, and decided to go to realbench.
It passed first time no problem. I then wanted to enable XMP on top of it, to see if it would pass realbench again, and it failed after 3-4 minutes saying "Instability Detected (luxmark)".

I tryid to disable my GPU OC and ran the test again, and it passed no problem.

I am wondering how it can pass realbench with CPU OC & GPU OC, but not with CPU OC, XMP & GPU OC ?
What is causing this behavior - what am I missing ?

Thanks in advance

Best regards
2,076 Views
4 REPLIES 4

Falkentyne
Level 12
Are you sure you stress tested long enough?

Did you have HWinfo64 running in the background with the bottom sensors field "WHEA" section open at the same time to look for errors that Realbench won't pick up?

It's completely impossible for a *CPU* overclock to fail with a CPU/GPU overclock but NOT with a CPU only overclock. There is no relationship at all between the CPU and GPU in that fashion, unless a PSU component itself is failing in some way. I suggest using Realbench 2.56 and doing a 4 hour stress test and have HWinfo64 open with sensors only, and watching the very bottom WHEA errors section. But then you said "instability failed" (Luxmark) which is the GPU section of the test--the CPU is not related to this test at all. So setting your CPU down to 3600 mhz for example, should still trigger this same instability. That means your video card overclock is not stable.

If somehow 'downclocking' your CPU makes your video card able to overclock again ...I would look at the quality of your power supply. The 12v voltages could be dropping too low. On some higher quality PSU's, simply replacing the PCIE cable with a spare from the box (anything above 550W should have more than 2 PCIE cables) will fix a GPU +12v problem. Otherwise you just need to upgrade your PSU if it's worn out or low quality.

HWinfo64 should allow you to monitor the main +12v line. Some motherboards also have a VRM section with the EPS12v input line separately from the primary 24 pin 12v reading. And some video cards also have a VRM that will show the 12v going into the PCIE power connectors. If you have one of those, you're lucky. Use it.

Also disabling XMP And suddenly being stable points to a problem with the cache ratio being too high, as XMP and cache frequency are related to the IMC. You can try adjusting your VCCIO and VCCSA voltages (usually 3200-3600 mhz memory will work on 1.20 IO and 1.25v SA without any drawbacks).

joppiano
Level 7
Thanks for your answer.

No, it wasn't long enough. Only did 1 hour test, while still adjusting "sliders" etc., to get a rough idea if this certain setting could potentially be stable or not.
When I have a rough idea that I might have a stable OC - I will let it run for 8 hours.

I am using Realbench 2.56 and I am keeping an eye on WHEA errors while testing, among other values ofc.
However, I did not pay any attention to the 12v parameter, so I have no clue how that looked whilst stress testing.

Also, CPU/GPU overclock didnt failed - it passed. The instability in luxmark only occured AFTER enabling XMP.

I have not tested RB whilst downclocking my CPU, but I just found it weird that it passed RB with CPU & GPU OC, but as soon as I enabled XMP it failed the test on the graphic part of the test (luxmark). And by disabling the GPU OC, the CPU OC + XMP passed RB.

After that I tested my GPU OC in TimeSpy, Superposition & Heaven and it passed everytime no problem.

My current VCCIO/SA voltages is at 1.150v each.

So I am not quite sure where the error is.

I assume enabling XMP does not affect the GPU in any way shape or form right? Which could lead to instability in luxmark.

Regardless to my PSU, I am using a Corsair RM750x, 10 months old. I am not sure if I got spare PCIE cables, I will have to check.

joppiano wrote:
Thanks for your answer.

No, it wasn't long enough. Only did 1 hour test, while still adjusting "sliders" etc., to get a rough idea if this certain setting could potentially be stable or not.
When I have a rough idea that I might have a stable OC - I will let it run for 8 hours.

I am using Realbench 2.56 and I am keeping an eye on WHEA errors while testing, among other values ofc.
However, I did not pay any attention to the 12v parameter, so I have no clue how that looked whilst stress testing.

Also, CPU/GPU overclock didnt failed - it passed. The instability in luxmark only occured AFTER enabling XMP.

I have not tested RB whilst downclocking my CPU, but I just found it weird that it passed RB with CPU & GPU OC, but as soon as I enabled XMP it failed the test on the graphic part of the test (luxmark). And by disabling the GPU OC, the CPU OC + XMP passed RB.

After that I tested my GPU OC in TimeSpy, Superposition & Heaven and it passed everytime no problem.

My current VCCIO/SA voltages is at 1.150v each.

So I am not quite sure where the error is.

I assume enabling XMP does not affect the GPU in any way shape or form right? Which could lead to instability in luxmark.

Regardless to my PSU, I am using a Corsair RM750x, 10 months old. I am not sure if I got spare PCIE cables, I will have to check.


What motherboard is this?
What RAM? You didn't really give us any system specs.

This sounds like your system agent voltage is too low...

Falkentyne wrote:
What motherboard is this?
What RAM? You didn't really give us any system specs.

This sounds like your system agent voltage is too low...


Sorry about that.

Specs:

i7-9700k
Asus Rog Strix Z390-F
NZXT Kraken X72
Asus Rog Strix RTX2070
Corsair Vengeance RGB 3000MHz @ 16GB (2x8)
Corsair RM750x


So, system agent voltage is, VCCSA yea ?
Also, how come that can cause instability in luxmark (the gpu part of the test) ?

So when I run Realbench with CPU OC, XMP & GPU OC it will detect instability (luxmark).
Even when running with VCCIO/SA on Auto, which puts it on 1.328v & 1.216v respectively, I will still encounter "Instability Detected (Luxmark)".

I changed IO to 1.250v & SA to 1.200v and did some tests.

CPU OC, XMP & GPU OC:
Realbench instability detected (luxmark) 13mins

CPU OC & XMP (GPU OC DISABLED):
Realbench 8 hours - Passed.

I am not quite sure why my GPU OC shows instability in Luxmark, when I can pass Superposition, Heaven, Firestrike & TimeSpy ??

I assume, that running with 16GB ram, you choose "Up to 16GB Ram" in Realbench right?