Question GPU in upgraded system prevents boot

[MarcusM17]

Hi all,

Hoping someone is knowledgeable enough to help me out. I recently picked up a new pc case and PSU, all other components worked properly in my previous rig (same components besides case/PSU).

Built PC, flipped on switch on the back of the PSU (not power btn on pc case), all my RGB sprang to life. Clicking the case’s power button didn’t see the fans spin or the system boot up, though. Took it apart, set the mobo up on its case, left in 1 RAM stick, CPU, and GPU. No boot. Swapped my 3080 ti for my old 1060 (same PSU), it booted to life just fine. I swapped out the new PSU for the old and tested, my 3080 Ti (and the rest of the machine) booted up. I’ve narrowed the issue down to the PSU (?) but the new, better PSU works fine with my 1060. Essentially, every configuration works except 3080 ti + new PSU.

Why would upgrading my power supply cause my GPU, which worked well in nearly the exact same, worse machine, prevent my system from booting?

I’ve tried swapping PCIE slots and PSU cables to no avail. I should mention my old PSU (3080 Ti worked) was a Corsair CX 650M.


Parts List:
-Ryzen 5 2600 (Ik I need to upgrade)
-MSI RTX 3080 Ti Gaming X Trio
-Toughpower GF1 850W 80+ Gold
-ASUS Rog Strix B450-F Gaming ii
-XPG Spectrix D50 (16GB 3600)

Thank you very much for any help!

 

[COLGeek]

When you swapped PSUs, did you also swap all of the corresponding cables (out with the old, in with the new)?

 

[MarcusM17]

When you swapped PSUs, did you also swap all of the corresponding cables (out with the old, in with the new)?

Thanks for replying. Yes, I swapped out the entire PSU (650M is semi modular, didn’t swap any cables between PSUs.)
It’s so weird. 3080 Ti + old PSU works. 1060 + new PSU works. 3080 Ti + new PSU doesn’t work.

 

[COLGeek]

Thanks for replying. Yes, I swapped out the entire PSU (650M is semi modular, didn’t swap any cables between PSUs.)
It’s so weird. 3080 Ti + old PSU works. 1060 + new PSU works. 3080 Ti + new PSU doesn’t work.

Are you using all 3 (separate, not using the daisy chain connectors) PCIe connections between the PSU and the GPU?

 

[MarcusM17]

Are you using all 3 (separate, not using the daisy chain connectors) PCIe connections between the PSU and the GPU?

I’ve tried using 3 individual PCIE cables as well as just 2 (1 daisy chain connector).

 

[COLGeek]

There are some known power issues with some Seasonic PSUs and high-end Nvidia GPUs, like your RTX 3080 ti. I suspect your PSU could be having similar issues.

I have a different 3080 ti that would not work with a particular PSU, but was perfectly fine with a different make/model.

You might be better served by returning the TT and getting something like a Corsair RM850.

 

[MarcusM17]

There are some known power issues with some Seasonic PSUs and high-end Nvidia GPUs, like your RTX 3080 ti. I suspect your PSU could be having similar issues.

I have a different 3080 ti that would not work with a particular PSU, but was perfectly fine with a different make/model.

You might be better served by returning the TT and getting something like a Corsair RM850.

Damn, okay thank you for your help. Putting the 650W back in until my new new PSU arrives lol.