Question CPU direct to GPU not working

[Spazimoto]

I just got a new board yesterday for my i7 8700k. I go to install the gpu in the first slot and got nothing. Since I had to use the second slot on my last board I didn’t just brush it off this time. After doing all the usual troubleshooting steps (installing drivers, reseating gpu, checking/updating bios and bios settings, etc.) I finally thought that since the whole point of using that first slot is to go right to the cpu maybe that’s the problem. So I left the gpu in and swapped to a different cpu and it worked….

So my question is what now? Is there anyway to get the i7 to recognize it or no?

Edit: here are my build specs
CPU: I7 8700k
CPU2(test unit): i5 9400f
GPU: 1660 super
MB: Aorus z390 pro
PSU: EVGA supernova 850 gold

Also another question along the same logic chain. Which would likely be better: running with the i7 with the gpu in the 2nd slot at x8 rather than x16, or running the 9400f in the primary slot using all 16 lanes?

 

[35below0]

First post your complete PC specs. You didn't mention your motherboard or what other CPU you used. What PSU do you have? And the GPU itself.

This information is important. Without knowing what you're working with, no one can offer any help.

 

[Spazimoto]

First post your complete PC specs. You didn't mention your motherboard or what other CPU you used. What PSU do you have? And the GPU itself.

This information is important. Without knowing what you're working with, no one can offer any help.

Understood:
CPU: I7 8700k
CPU2(test unit): i5 9400f
GPU: 1660 super
MB: Aorus z390 pro
PSU: EVGA supernova 850 gold

 

[CountMike]

Understood:
CPU: I7 8700k
CPU2(test unit): i5 9400f
GPU: 1660 super
MB: Aorus z390 pro
PSU: EVGA supernova 850 gold

Bios in UEFI or CSM/Legacy mode ?

 

[35below0]

You should always use the GPU in the primaru PCIe slot. Makes no sense not to.


The only cause that makes sense is the PSU not being able to supply enough power to the CPU and GPU. Because both CPUs can work, and the GPU can work, but not together with the i7 8700K.

Can you try with a different PSU?
Are you using cables that came with the EVGA PSU?
How old is the PSU?

 

[Spazimoto]

You should always use the GPU in the primaru PCIe slot. Makes no sense not to.


The only cause that makes sense is the PSU not being able to supply enough power to the CPU and GPU. Because both CPUs can work, and the GPU can work, but not together with the i7 8700K.

Can you try with a different PSU?
Are you using cables that came with the EVGA PSU?
How old is the PSU?

I am using the cables that came with it. It’s only a year or two old but not exactly sure. I do have another psu but it’s a proprietary non atx pinout from my old acer system. I could for the sake of the experiment just power the gpu with that one and everything else with the main psu. But If power delivery was the problem wouldn’t it not work in the second slot? Or does being in the express slot draw more power than the others?

 

[Spazimoto]

Bios in UEFI or CSM/Legacy mode ?

UEFI I believe I’ll have to check but I’m like ~75% sure.
Should I give the other option a try whichever one it ends up being?

 

[CountMike]

UEFI I believe I’ll have to check but I’m like ~75% sure.
Should I give the other option a try whichever one it ends up being?

No, modern GPUs need UEFI.