i913900k problem with i913900k and dual gpu

[andreas_fpv]

Hi,

I'm currently lost troubleshooting my i913900k and dual 4090 with 128 GB ram.

so with an i713900kf it works perfectly. everything works with no problems. but as soon as I put the i9 in it starts to not properly use gpu2. as soon as I request some information from it, or plug a display into it, it starts to flicker black and crash or switch to the igpu (using gpu1 as a passthrough). so if that happens I lose both the GPUs.

I tried everything I can think of and my colleagues can think of.

bios version-latest
driver-latest
only boot with 32 Gb ram.
only boot with gpu2 (doesn't work)
only boot with gpu1 (works)

and it seems like the CPU might be dead, but uhm that would suck.

please let me know if you need any additional info to help me troubleshoot some! thank you in advance!

 

 

 

parts:
mb: evga z690

ram: ddr5 4800mhz 32gb sticks (total 128gb) 

cpu: i913900k (i have an i713900kf for troubleshooting)

gpu: 4090 nvidia reference

storage: m.2 ssd (in bus 3)

[emosun]

3 minutes ago, andreas_fpv said:

and it seems like the CPU might be dead, but uhm that would suck.

if the cpu was dead the machine wouldn't post at all

It's more likely due to nobody using this specific config (two 4090s) that the boards firmware probably hasn't really been debugged. Probably worth a few emails to Evga and see what you get.

whats power supply make and model. also what was the issue using the i7 if it was working perfectly.

[andreas_fpv]

5 minutes ago, emosun said:

if the cpu was dead the machine wouldn't post at all

It's more likely due to nobody using this specific config (two 4090s) that the boards firmware probably hasn't really been debugged. Probably worth a few emails to Evga and see what you get.

whats power supply make and model. also what was the issue using the i7 if it was working perfectly.

using a 1600w evga psu.

 

got a custom bios version from evga they tested. should be the same as 2.04 on their website. i7 works with both custom version and version 2.04.

[Guest]

Are you running out of PCI lanes? Some motherboards only expect certain types of lane usage. If you're going 2x8+4 or something, make sure it can actually do that, and both of your GPUs aren't trying to use 16x lanes.

[andreas_fpv]

Just now, rootbeerdan said:

Are you running out of PCI lanes? Some motherboards only expect certain types of lane usage. If you're going 2x8+4 or something, make sure it can actually do that, and both of your GPUs aren't trying to use 16x lanes.

correct! but on the i7 it works so the motherboard seems happy. and also they are locked in bios at x8 gen 4 speed. fully supported by the mb spec.