5870 question.

[H4wXx]

I was having a problem with my 5870, which I diagnosed to be my power supply not able to provide enough power to my 5870. I cannot get a new power supply at the moment, so I was wondering if underclocking my 5870 would possibly solve my problem and also if I run the risk of damaging my card via underclocking.

On a side note I was wondering if running a video card without enough power runs the risk of damaging it or other system components.

Thank in advance.

 

[Kowan]

Underclocking wouldn't reduce much draw, but it would work okay for the card.
Stressing the PSU could kill components or just kill the PSU.

Are you running multi-fans in your case? Multi-optic drives, hard drives etc.?
You could unplug them for a less power hungry system.

 

[H4wXx]

Ah, ok. I'm only running one HD, 5 fans, the videocard, and the cpu & mobo. Unplugging the optical drive didn't make much difference though. It's a 500w PS which I figured would be enough, but apparently it's not.

I'll just put the old vid card back in until I get a new PS then, thanks for the help.

 

[sirmonkey1985]

what psu is it and what are the amps on the 12v rails? would give a better idea of if it is actually the psu..

if you are able to underclock and undervolt the gpu then it would cut down on the power usage.. wouldnt really do any damage to the card since it should protect its self before that happens by shutting the system down..

 

[H4wXx]

It's an Antec Earthwatts 500w and the amps on the 12v rails are 17 a piece, though I've just put in my old card for now until I get a new PSU (an nVidia 8600 GTS, quite a downgrade, lol).

The reason I think my power supply is the issue is because I was having an issue with the blower fan on the 5870 pulsating before my computer would post, rather then just spinning at max, and then slowing down after like it should. This issue would get resolved sometimes when everything would be unplugged besides the 5870 and CPU/Mobo/Ram, it didn't work consistently, but I found that using one of the dedicated PCI-E power cables and a 12v Molex to PCI-E adapter I could get enough juice to have the computer start normally without the pulsating. However it would only work with 1 of the PCI-E cables, and using one Molex connector of off two separate cables. To add to all of this when I had everything including the DVD plugged in my computer would hang every 4 seconds or so for a period of about 5 seconds, which stopped once I had unplugged the DVD drive again. Everything works fine now though that I'm back to using my 8600 GTS.

I'm not sure if it's the wattage or the amperage that is the problem though, since my knowledge of these things is limited.

Edit: There's only 2 12v rails, forgot to mention that.

 

[Spare-Flair]

It's an Antec Earthwatts 500w and the amps on the 12v rails are 17 a piece

I've seen recommendations of at least 40 amps. You have a total of 34 amps. If your PSU is hot, the power efficiency drops even more, like 30%.

Wattage itself isn't that important as long as you cover the full system load but videocard is very dependant on amperage.

 

[H4wXx]

Thanks for that little tidbit of info, I'll make sure to get a PS that has an amperage of at least 40 if not more. I figured it was probably the amperage, 34 total amps seemed a little low to me to be able to power such a beefy card.