Render SO SLOW...CPU blocked to 25% :(

[eric_barbaron]

hi all,
i ve got an issue since a few days.
When i render to vray CPU (with 3dsmax2020), the cpu is stuck to 25%
.
we are in a big rush and i dont what to do anymore.
This pc worked well just before.

Do you have any idea to resolve this issue?
did anyone have got a similar problem?

Pleazzzz help

Here are some pics (shot during a render with vray CPU)

Big thx in advance for your reply.

Eric

[Alex_M]

Hi eric_barbaron ,
Are you using the "Progressive" sampler by any chance? I'm having the same problem in a scene I'm working on currently when using "Progressive". Try changing the sampler to "Bucket" and Vray should use 100% of the processor.

[eric_barbaron]

hi Alex_M,
thx for your reply,

but NO, unfortunately, in "progressive" or "bucket", it's the same thing.
Its so frustrating.!!!

I finally reinstalled win10 (from local drive)
reinstalled Max2020 and Vray (the last one)
and it is the same f*****g result.
I spent a ton of time, trying and testing cpu, gpu with different software like OCCT.
Everyting seems to be ok,

the CPU sticks to 25% (more or less)
Is it dead?

Isn'it cause of the "low thread priority"?

I dont understand anything anymore.

Chaos team, any idea?

[Alex_M]

Sorry to hear this. I can imagine the frustration. Is it only in Vray that you have this issue? Does it happen with every scene? Is other rendering software acting the same way? Can you try the Cinebench R23 benchmark software and see if all cores are used there?

[super gnu]

it seems like something is wrong with your workstation, or windows.. its reporting your clock speed at 0.9 ghz!

i have the same processor, win10, max2021, vray 5/6 and i get 100% utilisation unless im doing very small region renders, and my clock speeds are reported correctly... i have PBO enabled so usually it runs around 4ghz..

not sure how tha relates to the low utilisation though..

[Alex_M]

Good catch, super gnu . Since this was not resolved after complete OS reinstall, there's a chance it's BIOS related. I would try resetting BIOS to factory defaults to see if this fixes it.

[eric_barbaron]

hi guys,
thx for your help

I tried to reset Bios to factory default. And it is the same thing. Maybe worse

I made a test with OCCT. At the begining, in the task manager, the CPU was at 100%...After 30s., it was at 45% , and to stay at 18% after a few minutes. Amazing !!!!

I made a test with Cinebench. same shit!

Its like if win10 blocks the cpu to a low value.

[super gnu]

looks like its overheating, have you checked temperatures? HWinfo is good.

to drop to 0.9 ghz, are you sure theres a cooler installed at all?

id fix that quick, its a damn expensive chip to be cooking it repeatedly. even if it does not break, the lifetime could be drastically reduced.



EDIT: i see it shows temps in OCCT... if its hitting 95 degrees at those low clock speeds your cooler isnt doing very much.. check its installed properly and somebody didnt forget to installl thermal paste or a fan..

iirc 95 degrees it will definitely be thermal throttling. dont use it any more till you fix the issue!!!


ive got a huge watercooler on mine, manage to keep temps below 60 degrees even at 4+ghz.. I would not be happy with anything above 70-75 on a chip like the 3990... i dont believe they are even selling them any more so be careful!

[Alex_M]

Thanks for the new screenshots, eric_barbaron . I can see that your system does use all of the CPU resources, but only briefly. I also see that the CPU hits 90-95*C which is the limit of the CPU. This tells me that this is probably a cooling issue. Either your CPU or your motherboard (or both) are having problems with the cooling so the CPU slows itself down to protect itself from thermal damage. Please carefully check if all fans on the CPU and the motherboard work correctly and if the cooler is properly mounted and if it has enough thermal paste. If you use water cooling, your water pump might have failed or maybe the CPU water block is clogged with debris. So you may have to clean it, flush the entire water loop system and fill it with completely new liquid. Don't use the PC until you do this or you might damage the CPU and motherboard irreversibly.

super gnu beat me to it.

[Muhammed_Hamed]

Like what Alex_M and super gnu said, this is about thermal throttling..
A bad cooler is my guess, you also need a very good board for this CPU, any entry-level/cheap boards will have issues

Pretty much all AIOs will not play well with this CPU, your best chance is something like Noctua NH-U14S

Best,
Muhammed

[eric_barbaron]

Thx a lot guys for your help
I finally found the issue.
It apperas that the water is fucked up.
Go back to the screw driver!!!

Thx again