Question New Ryzen 9 5900x black screens when starting cinebench r23 ?

epicninja

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Aug 17, 2014
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Recently got a new Ryzen 9 5900X which I swapped in for my old 3600 and I'm getting some weird behavior. Most workloads go perfectly fine (ran an hour of prime 95 blend + furmark, worked like a charm, occt, heaven, various games, all performing as expected). However, I tried cinebench r23 today and as soon as I click the start button for either the single core or multicore tests I instantly black screen (monitor reports no input). Not only that, but my peripherals (keyboard and mouse) shut off (i.e. backlights turn off) and the front power button (connected to mobo) no longer works. The fans keep spinning however. The only way to turn the pc back on is to manually cycle the PSU, at which point there are no errors in reliability other than improper shutdown and no dumps in the Windows folder. Somehow, Cinebench also becomes corrupted, and I need to reinstall it to open it again.

I'm thinking it's some sort of PSU or Mobo problem but I'm not sure why this particular load would cause a black screen, when much more intense tests like Prime95 show no stability problems even after an hour. Can anyone shed some light on this?

I did the standard things: reinstall chipset drivers, update windows, run CCleaner, etc.

Full specs:

Ryzen 9 5900X
X470 MSI Gaming Plus (latest bios)
16gb Corsair 3600 (dual channel)
RTX 2080 Gigabyte Gaming
EVGA Supernova G2 750W
 
Last edited:

epicninja

Honorable
Aug 17, 2014
50
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10,545
Hey there,

Are you OC your CPU? PBO on?

Also running Prime95 blend will not stress your CPU. You might try small fft's and see if the same thing happens (like CB23). The black screening is not indicative of a PSU issue, but can't rule it out either just yet.
No OC or PBO, ran small fft's for an hour and 15, no errors. I bought a new mobo since the PSU seems solid from my further testing so I will swap my cpu into that tomorrow when it arrives and see what happens.
 

epicninja

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Aug 17, 2014
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10,545
No defo not. I mean, CB23 does put a very quick high load on to the CPU, but is that enough to trip the PSU. Have you another you could swap out with?
I swapped out the mobo, and that fixed my issues, at least so far. 10 min of cb23 + significant time running another app that guaranteed quick crashes (never made it past 30 seconds). No idea what the exact problem was and why these specific loads caused instability but I'm happy that my first try worked, even if I had to buy a whole new mobo. Thanks for your help!
 
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I swapped out the mobo, and that fixed my issues, at least so far. 10 min of cb23 + significant time running another app that guaranteed quick crashes (never made it past 30 seconds). No idea what the exact problem was and why these specific loads caused instability but I'm happy that my first try worked, even if I had to buy a whole new mobo. Thanks for your help!

Oh, that's great. Result! No worries, glad to have assisted.