Question New PC Build - Facing problems with PCIe GEN4

Jan 19, 2022
Hello Everyone,
I built a new pc three days back.

Processor: Ryzen 5600x
Motherboard: MSI B550-A Pro
GPU: RTX 3080 10GB Rev 3.0 (Gigabyte Aorus Master)
Ram: 8gb x 2 (3200 Mhz)
PSU: Cooler Master 850W Gold Edition

So these have been long 3 days for me. This is my first PC built and I was fairly worried about how It would come up.

Plugged everything in place (I am omitting details but it was a <mod edit language>💩 show - CPU cooler assembly was a nightmare, broke my case's tempered glass into literally thousands of pieces, changes PSU since original one I got sounded like tractor when switched on + thousands of things going wrong when building in a case - I didn't even know it was so much better to built the pc on a cardboard box first time), anyways

Windows came up just fine, with basic Microsoft Display adapter.
I downloaded NVIDIA latest drivers and it didn't complete first time through, tried multiple times, finally got through it with a slightly older version.

Now I opened a Web Browser and CRASH ! Pc restarts
I downloaded some benchmarking tools from other pc and tested on them,

Heavens Unigine was giving 5-10 FPS for 3080, PC crashing everytime I am running Passmark Burn in Test 3D Graphics or any application using GPU's 3d engine. (2D engine was working fine).
Benchmarks for all the other components (CPU, RAM, SSD) were successful.

Checked the Wattage, CPU was fine, RAM, but 3080 is pulling a miraculous 60-65W only. Wow !

Without thinking anything I contacted the retailer that my GPU is bad piece, and would want to change it. They were looking into that, and in the meanwhile I thought to test the other PCIe slot that comes with the mobo.

So I plugged my 3080 into that and bam, system was running flawlessly, Best of scores on Heavens Unigine and passing all stress tests.

I figured out that the PCIe slot I used before was a Gen4 slot and the bottom one was Gen3. Then I went into BIOS and forced Gen4 slot to work in Gen3 mode, and plugged my 3080 back again into the original slot, and my system was running flawlessly again.

Running 3080 on a PCIe slot with Gen4 is causing it to crash and not work properly. Changing the same PCIe slot to run in Gen3 mode works flawlessly.

My questions is what could be the point of failure. Processor? Mobo? GPU?

And should I even bother about making it work with Gen4 because it is working fine with Gen3 and doing RMA's and debugging the problem can take a long time and is literally a nightmare.

Your thoughts Peeps !
Last edited by a moderator:
Jan 19, 2022
Motherboard may need BIOS update.
I did. To the latest version but it didn't do anything.

I wouldn't. Performance difference should be close to zero.
Yea I saw gaming benchmarks and PCIe3 was actually better than 4 in some cases. But what happens in the future when games become more demanding. I mean surely PCIe4 will perform better with that extra memory bandwidth
Jan 19, 2022
PCIE bandwidth starts playing role, when vram size is not enough anymore.
With 10GB of vram you're quite fine there.

But if some future game requires more than 10GB of vram, performance will tank either way.
You'll have to adjust graphics quality settings.
Okay I can live with PCIe3 then. But just being curious here, what could be the problem? I did BIOS update but didn't clear the CMOS, maybe BIOS update didn't go fine. Can this potentially be a hardware issue (like mobo or processor damaged slightly somewhere and not manufacturer hardware issue) or purely firmware based?