Question Cannot boot PC - Asus TUF B550 and Radeon RX 6750XT

[maxxam97]

Hey there,

I'm looking for help with my PC. The full configuration below:

CPU Ryzen 5600
Mobo Asus TUF B550
GPU Gigabyte RX6750XT (changed from GTX 970)
2x8 GB DDR4
2x 1TB HDD
1x 500 GB M2 SSD
1x 120 GB Sata SSD
Seasonic 550W Gold

Everything was bought new.

The problem is that I cannot boot my PC in that specification while using primary (higher) PCIe for GPU. Everything is working fine when it's connected to secondary (lower) PCIe but it's much slower than primary one.
When the GPU is connected to the top PCIe, the computer starts, fans spin, and dots blink in the order VGA (white), CPU (orange), VRAM (red) but in about 5 seconds PC reboots again. No image is displayed during that...

Worth mentioning that, the old GTX 970 worked fine on top PCIe.

I have tried to reset the BIOS of MOBO, update that etc. Nothing helped. Even with no disks attached, I still cannot even open BIOS.

I asked my friend to help me with the investigation. He did some tests and told me that:

1. The card worked fine on almost all MOBOs. Only one B550 (except mine) didn't boot up.
2. Almost all GPUs worked fine on the the top PCIe - but as previously, not all.

What do you think about this? Did you hear about anything similar on those models? Is there any matrix of `incompatibilities between CPU and GPU`?
I can return parts of my computer to the shop for a warranty but I'm not sure what parts I should complain about.

 

[logainofhades]

550w is possibly too low for a 6750xt. How old is said PSU? I would try a CMOS reset regardless. Make sure Bios is up to date.

 

[maxxam97]

PSU is like 6 months old, bought brand new. I think if really that can be a problem. Notice that GPU work fine on secondary PCIe so I guess the power consumption should be almost the same for both top and bottom PCIe.

Tried to CMOS reset and updating BIOS - nothing helped.

 

[logainofhades]

It sounds like it is a problem with your particular motherboard then. Might try going back to your 970, and then go into bios, and checking what gen the graphics PCI-E is set to. Try setting it manually to gen 4.

 

[maxxam97]

I did quite the same.
1. Inserted GPU to lower slot. GPU started fine.
2. Changed AUTO to GEN4 for top PCIe.
3. Inserted GPU to top slot.
4. Didn't boot

 

[logainofhades]

Then I say something is wrong with that motherboard.

 

[maxxam97]

Hmm, and even if old GPU (that GTX 970 I've mentioned) is running fine on top slot, then it's still very likely to be a problem with MOBO, right?
If so, I will return that to shop to have repaid that under the warranty... Hope they will have the same GPU as mine.

I'm thinking about that case because for some other GPUs top slot worked fine. I need to ask colleague what GPU did he test there - maybe there is a problem with newer GPUs for my MOBO?

 

[logainofhades]

I have heard of Asus boards not liking particular GPU models before. I think it happened to jayztwocents a year or two ago. Same GPU series, just different brand, and one card would work, where the other would not.

 

[maxxam97]

Oh gosh. It doesn't sound fine - probably warranty will not cover that and I will be forced to sell it and buy new one.

Don't you have the jayztwocents's post somewhere?

 

[logainofhades]

It's an older video of his. I don't remember when exactly he posted it.

 

[maxxam97]

Still thinking about that case and I realised that before I've bought RX 6750XT, I had bought RX 6700XT from second hand. GPU didn't start on top PCIe as well but I thought there was a problem with GPU.

Then I've bought the GTX 3070 from second hand again. The card started on top PCIe but with it was so slow (like 30 fps in old games even if GPU was used in 80%).
Then I've decided to buy brand new card but unfortunately, there are similar issues like in RX 6700 XT.

I will make a compliant in next week. Have fingers crossed.

 

[logainofhades]

With all those different GPU's all having issues, in the top slot, I would conclude the motheboard has an issue and needs to be replaced.

 

[beyondlogic]

Still thinking about that case and I realised that before I've bought RX 6750XT, I had bought RX 6700XT from second hand. GPU didn't start on top PCIe as well but I thought there was a problem with GPU.

Then I've bought the GTX 3070 from second hand again. The card started on top PCIe but with it was so slow (like 30 fps in old games even if GPU was used in 80%).
Then I've decided to buy brand new card but unfortunately, there are similar issues like in RX 6700 XT.

I will make a compliant in next week. Have fingers crossed.

if i was to guess it sounds like the pci slot isnt providing enough power

the gtx 970 might be working of the power it gets of its pin header

also try removing all drives from motherboard and just have the graphic card plugged in see if it posts

try replacing the hdmi cable or display port cable as well.

make sure that the actual cable is plugged in correctly some pc cases rear hole plates get in the way of some bulkier hdmi or display port cables.

 

[logainofhades]

Speaking of power connectors, are you using a separate PCI-E cable for each PCI-E connection on the graphics card?

https://knowledge.seasonic.com/arti...ark-for-high-power-consumption-graphics-cards

 

[SkyNetRising]

I did quite the same.
1. Inserted GPU to lower slot. GPU started fine.
2. Changed AUTO to GEN4 for top PCIe.
3. Inserted GPU to top slot.
4. Didn't boot

Force it to Gen 3 instead.

BTW - are you using any PCIE risers?
Anyway - minimum recommended PSU for Gigabyte RX6750XT is 650W.