Can a Graphics Card be bottleneck by low power draw?

[Crix525]

Running a generic 400 Watt power supply for years, I decided to get a GTX 960 for its low powerdraw and efficiency. The problem is that its not performing as expected when paired with a Core i5 2310 and 8GB of Ram. Its been a problem for a while now until I decided to switch connections on my power supply (Removing shared power connections from the GPU) then the problem just seemed to disappear. I get no more microstutters, can play games at higher settings with more consistent frame rates. So now I'm wondering if a low power draw can affect gaming performance so I can get around and fix that problem.

 

[Eximo]

Absolutely. If it is generic, and it is as old as the CPU, then it has probably lost some of its max output by this point due to capacitor aging. Probably has a 360W 12V total or something similar as well, so not quite 400W. Higher the temperature the less efficient it is, and the lower its output will be. Since moving things around helped, that also indicates a multi-rail design. Normally they keep the CPU input and GPU power separate from the rest of the peripherals. Depends on how you hooked it up I suppose.

You should have a quality 500-550W single rail supply in there.

 

[Crix525]

Absolutely. If it is generic, and it is as old as the CPU, then it has probably lost some of its max output by this point due to capacitor aging. Probably has a 360W 12V total or something similar as well, so not quite 400W. Higher the temperature the less efficient it is, and the lower its output will be. Since moving things around helped, that also indicates a multi-rail design. Normally they keep the CPU input and GPU power separate from the rest of the peripherals. Depends on how you hooked it up I suppose.

You should have a quality 500-550W single rail supply in there.

So what you're saying is that I can get the best of my GPU and CPU if I upgrade to a quality power supply even if they are still operable now?

 

[Eximo]

No, I am saying you are on the ragged edge of the PSU failing. If it fails gracefully, no harm done. But it could damage components on failure. There may be a tangible performance benefit if the card is still throttling under a heavy load sometimes.

Additionally, if the power it is providing is no longer smooth, which happens when they operate at high temperature or on the edge of their limits, then the VRMs on your GPU and Motherboard are getting additional wear and tear by having to smooth the incoming power.

I would take a look at specs plate on your power supply and report back. Specifically the +12V amperage/wattage totals. Head on over to pcpartpicker.com and put all your components in to get an estimated wattage total.

 

[Eximo]

No, I am saying you are on the ragged edge of the PSU failing. If it fails gracefully, no harm done. But it could damage components on failure. There may be a tangible performance benefit if the card is still throttling under a heavy load sometimes.

Additionally, if the power it is providing is no longer smooth, which happens when they operate at high temperature or on the edge of their limits, then the VRMs on your GPU and Motherboard are getting additional wear and tear by having to smooth the incoming power.

I would take a look at specs plate on your power supply and report back. Specifically the +12V amperage/wattage totals. Head on over to pcpartpicker.com and put all your components in to get an estimated wattage total.

 

[Crix525]

No, I am saying you are on the ragged edge of the PSU failing. If it fails gracefully, no harm done. But it could damage components on failure. There may be a tangible performance benefit if the card is still throttling under a heavy load sometimes.

Additionally, if the power it is providing is no longer smooth, which happens when they operate at high temperature or on the edge of their limits, then the VRMs on your GPU and Motherboard are getting additional wear and tear by having to smooth the incoming power.

I would take a look at specs plate on your power supply and report back. Specifically the +12V amperage/wattage totals. Head on over to pcpartpicker.com and put all your components in to get an estimated wattage total.

I believe it has 28 Amps on the 12 Volt rails. And temperature wise its surprisingly running really cool and with no hints of burning smell. My PC has never suffered an emergency shut down because of the power supply to my knowledge. I have taken counter measures to prevent failure by plugging in the computer on surge protectors and battery backups. Before I had a harddrive and two case fans sharing the same power connection on the GTX 960.

 

[Eximo]

GPU is taking 1/3 right off the top, 200W for the rest of the system seems reasonable. Still a little low though. Ideally you want to keep a PSU between 50-80% load. As long as it stays cool, you should be fine.

The problem with generic supplies is that you really don't know how good they are without examining the parts.