x570 Tomahawk with GTX 1080 on Top PCIE doesn’t want to display.

Mareczin · 20 Sep 2021 at 08:46

Hey all, I recently changed my motherboard, cpu and ram and everything works fine if I insert the GPU into the 4th PCI slot but the VGA light comes on and stays on in the first slot. The EZ debug light for VGA goes off anytime the gpu is plugged in the top slot (16x) over the bottom (4x). I should also note that when the GPU is plugged into the E1 slot, I get a VGA debug light. The GPU is also less audible when I plug into E1 unlike when I plug it into E3 where you can clearly hear the GPU fans spin aggressively. The first slot is not damaged because the gtx 950 card inserted in the first slot works and starts the system. Any idea what I can do friends :/?
Motherboard: MSI MAG X570 TOMAHAWK WIFI
SSD: x1 Samsung 970 EVO Plus NVMe M.2
CPU: AMD Ryzen 5900X
RAM: 32GB Patriot Viper Steel DDR-4000 Kit 4x8
GPU: MSI GeForce GTX 1080 GAMING X+
BIOS Version: 7C84v17

mickyflinn · 20 Sep 2021 at 09:28

Change the first gpu slot speed to pcie3 in the bios see if that makes any difference.

Haz123 · 20 Sep 2021 at 09:28

Go into Bios and check the PCIe slot you want to use is set to PCie 3.

Are the power cables seated properly when trying to use the 1080?

Mareczin · 20 Sep 2021 at 09:29

mickyflinn said:
Change the first gpu slot speed to pcie3 in the bios see if that makes any difference.

You mean generation PCIe 3 or lower than 4? Checked and same problem, no difference.

Haz123 said:
Go into Bios and check the PCIe slot you want to use is set to PCie 3.

Are the power cables seated properly when trying to use the 1080?

Yeah, on 4th slot working fine, so PSU and cables be fine.

MissChief · 20 Sep 2021 at 09:55

So the card works, this has been proven. My thought then is the slot. Do you have another known working card to test? It doesn’t have to be anything amazing, I have an old 9600GT lying around which is PCI-E and it’s perfect for testing. There’s every possibility it could be the slot.

Mareczin · 20 Sep 2021 at 10:01

MissChief said:
So the card works, this has been proven. My thought then is the slot. Do you have another known working card to test? It doesn’t have to be anything amazing, I have an old 9600GT lying around which is PCI-E and it’s perfect for testing. There’s every possibility it could be the slot.

"The first slot is not damaged because the gtx 950 card inserted in the first slot works and starts the system." :/

mickyflinn · 20 Sep 2021 at 10:12

Set everything to stock if overclocked and try running just 2 or a single stick of memory.

MissChief · 20 Sep 2021 at 10:17

Mareczin said:
"The first slot is not damaged because the gtx 950 card inserted in the first slot works and starts the system." :/

Does the 950 use all the contacts on the full length of the slot?

Mareczin · 20 Sep 2021 at 18:52

MissChief said:
Does the 950 use all the contacts on the full length of the slot?

Yes

mickyflinn said:
Set everything to stock if overclocked and try running just 2 or a single stick of memory.

Never overclocked, all default. Also i tried your idea with 2 or single stick of memory same problem.
BUT i found something really weird

I was able to run the graphics card in the first slot by changing the PCIE generation to 2.0
After changing to generation 3.0 or 4.0, the board does not detect the graphics card. Clearly the problem lies with the motherboard. Does anyone have an idea what's going on? As a last resort, my question is what is better: gen 2.0 x16 or gen 3.0 x4?

Haz123 · 20 Sep 2021 at 19:20

IIRC each generation of pcie doubles the available bandwidth so pcie 2 x16 should be twice the bandwidth of PCI 3 X 4. Would be equivalent to pcie 3 X 8.

I would reflash the bios one last time and if still the same issue then think about RMA the mobo.

mickyflinn · 20 Sep 2021 at 21:09

Echo the above reflash bios maybe diffrent version if no joy them return the motherboard.

glenimp617 · 25 Sep 2021 at 09:05

I had this problem with the X570 tomahawk. There's also another forum member who had it.

Mine was a faulty board. The replacement is fine. The other members issue was with his nvme drive, although I had the same one and mines ok, worth checking.

Purgatory · 25 Sep 2021 at 10:13

Mareczin said:
Hey all, I recently changed my motherboard, cpu and ram and everything works fine if I insert the GPU into the 4th PCI slot but the VGA light comes on and stays on in the first slot. The EZ debug light for VGA goes off anytime the gpu is plugged in the top slot (16x) over the bottom (4x). I should also note that when the GPU is plugged into the E1 slot, I get a VGA debug light. The GPU is also less audible when I plug into E1 unlike when I plug it into E3 where you can clearly hear the GPU fans spin aggressively. The first slot is not damaged because the gtx 950 card inserted in the first slot works and starts the system. Any idea what I can do friends :/?
Motherboard: MSI MAG X570 TOMAHAWK WIFI
SSD: x1 Samsung 970 EVO Plus NVMe M.2
CPU: AMD Ryzen 5900X
RAM: 32GB Patriot Viper Steel DDR-4000 Kit 4x8
GPU: MSI GeForce GTX 1080 GAMING X+
BIOS Version: 7C84v17

Stick the GTX 1080 in a working slot or pc and run this tool to update the firmware to the latest DP specs. Then try it again on the first pci slot.

NVIDIA Graphics Firmware Update Tool for DisplayPort 1.3 and 1.4 Displays

https://www.nvidia.com/en-us/drivers/nv-uefi-update-x64/

Also what monitor are you using ? You may need to turn eco modes off on the monitor to allow it to wake up on post, some monitors also cause issues.