Windows7ge

3 minutes ago, Schnoz said:

The power supply I'm using does have a cable with way too many Molex connectors on it, and it should definitely be long enough to reach the GPU. Just curious, what model of fan are you talking about?

A DC Brushless FD7525U12D 75mm. Came out of my Sapphire Radeon HD 7970 from like 2014.

21 hours ago, Schnoz said:

That length range should be enough, though I can extend fan cables with some of those 30cm fan cables that came with my NF-A4s. I'm currently controlling the GPU fan speed from BIOS by connecting only the GPU fans to CHA_FAN and connecting all the other fans to CPU_FAN.

Because the fan can draw up to 1.7A @ 12V I'm not putting a 4-pin on the fan. It's going to be molex for power direct from PSU then a 4-pin for testing TACH + PWM. If you have Molex extensions handy that'll work.

1 minute ago, Schnoz said:

For the power cable, I'm using an EPS12V to dual 8-pin adapter similar to this one, which is connected to the 8-pin and 6-pin PCIe connectors on the nonmodular 500W power supply it's hooked up to. I'm probably using around 45-55cm of power cables in total at the moment, as well as a 30cm PCIe x16 riser.

 

I'm planning to use the duct you're designing with a second one that I'll probably make out of cardboard and tape, on the opposite end of the card to better overcome the pressure drop. I've actually built a second duct, and I'm testing it right now. The P100 now boosts considerably higher when folding, and I think it'll actually be able to handle a 100% power limit with your duct installed.

 

Thank you again for taking the time and resources to do this. I really appreciate it.

So 1.5ft or about 45cm should be long enough?

The blower motor has TACH and I believe PWM functionality. Though these functions are supposed to run through the GPU I might be able to get them working on a motherboard fan header. If it works you would be able to control the fan speed from within the OS or the BIOS at least. Without resorting to throttling direct DC voltage.

On 11/13/2021 at 9:46 PM, Schnoz said:

I understand that you're quite busy, and I really appreciate that you're taking the time to help me like this. Please don't feel rushed to take care of it right away; I can use a makeshift duct with cardboard and tape until then. Sorry for any bother, and thanks again!

How long of a power cable would be good for you?

Assuming I can get the .STL file for the duct on thingiverse making a new housing for the motor/blade assembly out of a Radeon HD 7970 won't be any trouble. I'll even see if I can adapt the GPU PCB connector to a standard 3/4-pin. It'll have to be a 2/3 part assembly though so either screws or tape will have to hold it together.

I'm also working 40+ hour weeks so although I volunteered it's not something I can guarantee you'll get ASAP nut I'd like to see what that card can do when it actually has adequate cooling.

Thanks for giving us the word and telling us at least what you think the problem was specifically. Most other non-tech sites would probably tell you "hardware problems" at the most assuming nobody has the knowledge to understand what the specific issue really was despite wanting better answers.