Can't get Sapphire ATI Radeon HD 4870 to work

TempoTutor

Commendable
Jun 19, 2017
20
0
1,520
I'll start of by giving a list of the components in my setup to give you an idea of what I'm working with.

Motherboard: Asus P5B (might be some sub-model; it's orange but only says P5B)
CPU: Intel Core 2 Duo E6850 @ 3.0 GHz
Memory: 3 GB DDR2
PSU: Colors-It 500W
OS:Windows 7 Ultimate (x64)
Current GPU: An old Sapphire ATI Radeon 9200 that barely works
New GPU that I can't get to work: Sapphire ATI Radeon HD 4870 (1GB GDDR5; 750MHz core clock)

I've properly installed 4870 and plugged in both PCIe cables, but when I try to turn the computer on, it turns on for a split second and then turns off, and tries to boot again, in a sort of endless loop. The computer runs fine when I unplug one of the PCIe cables, but Windows doesn't detect it. By the way, I'm using Molex to PCIe adapters since the PSU is non-modular.

If there is anything I could do to make this work, please let me know, and feel free to ask any questions about my setup. Thanks!
 
Solution

Alright, I had feared that. Thanks for the advice.


That can be ruled out because I got the GPU from a friend and he had tested it and it was working just fine. You're probably right with the PSU thing.

Update: I'm...

huskysonian

Honorable
Jun 19, 2017
42
0
10,560
I'd say that your power draw is likely inadequate. I had a similar issue while trying to put an old HD 6000 series card into a workstation PC that needed something better than the iGPU and had a poor idea of what the PSU was supposed to output.

Personally, adapting to PCIe from molex is inadvisable for powering GPUs. I'd prefer to work with something that can output the power you need using PCIe plugs.

Alternatively, maybe the 4870 is dead? If you got it second hand untested, then that could be a solution. Try a new PSU first, though.
 

TempoTutor

Commendable
Jun 19, 2017
20
0
1,520

Alright, I had feared that. Thanks for the advice.


That can be ruled out because I got the GPU from a friend and he had tested it and it was working just fine. You're probably right with the PSU thing.

Update: I'm looking into a Corsair CS600M 600 Watt PSU. Is it a good idea? I'm just trying to stay on the cheap side and have found a good used one.

Update #2: Nevermind! I took out the 9250 and the HD 4870 now works fine! My guess would be that either A: the motherboard couldn't handle both cards; B: PSU couldn't handle both cards, or C:\ there was some kind of built-in mechanism in one of the computer's components that prevented them from running at the same time. My money's on either A or B.
 
Solution