new gpu with old 500w psu

[Scyvh]

Hey all,

I'm looking to upgrade the GPU of my away-from-home computer (i5 2500k, 8gb, 500w). It currently has a gtx 560 and runs it smoothly. Because it isn't my main computer I'd rather not invest in a new PSU unless it is absolutely necessary. I won't be overclocking in the near future; in that case I would invest in a new PSU.

The current PSU limits my choices though, it isn't a top model (cooler master RS-500-PSAP-J3) and it only has two 6 pins (through a molex converter) for the GPU. I'm not a PSU expert, but it has two 12v rails with 20A each.

I'd be looking to upgrade into the 960/770/970 range, foregoing the specific cards that have an 8 pin. I've read conflicting things, with some saying 500w would even power a 970?

Would anyone happen to have an idea which cards would be safe? Perhaps someone has been in the same conundrum?

Thank you for your advice.

 

[clutchc]

I definitely would not trust that PSU with a GTX 770. The GTX 970 and 960 would be OK with it. But the quality of that line of Cooler Master PSU is poor. Use it knowing you are doing so at your own risk.

 

[jerdle]

the 960 will be fine

 

[Scyvh]

Thanks Clutch and Jerdle. Do you reckon the 970 would be stretching it too much compared to the 960?

I'd also be interested in slightly older cards that might be an alternative (though I reckon those will draw more power than the 960/970).

 

[Scyvh]

Sorry for bumping. Do you think the 970 would be stretching it too much compared to the 960?

A friend has a spare gtx 770, but I reckon it would be less power efficient than the 970?

 

[jerdle]

a 970 should work.

 

[clutchc]

Sorry for bumping. Do you think the 970 would be stretching it too much compared to the 960?

A friend has a spare gtx 770, but I reckon it would be less power efficient than the 970?

Check the nameplate on the PSU. If it is this one: https://www.google.com/search?q=cooler+master+RS-500-PSAR-J3&biw=1600&bih=797&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjisPCF677KAhUlroMKHRCeAocQ_AUIBygC#imgrc=qq8_F4cTvPuvUM%3A
...you might just squeak by with a GTX 970 if it has 2 x 6pin connectors and you don't OC. But again, the PSU is not the best quality. You'll be taking a chance that it might fail under extreme use.
I would not run a GTX 770 on it, tho.

 

[Scyvh]

Thanks jerdle and clutchc (again!). Seems risking the 770 wouldn't worth it.

I double checked; I have the PSU you just linked. That would mean I have 40A in total on both 12v rails? (20A.2?)

It seems the EVGA SC 970 with 2x6 pins might be a good option then?

 

[clutchc]

Thanks jerdle and clutchc (again!). Seems risking the 770 wouldn't worth it.

I double checked; I have the PSU you just linked. That would mean I have 40A in total on both 12v rails? (20A.2?)

It seems the EVGA SC 970 with 2x6 pins might be a good option then?

Well... the Evga OC version of the GTX 970 might be a bit much for the PSU's +12V rail. I'm not saying it won't work, just that the PSU will be taken to its max at times. Life expectancy of the PSU will be less and failure may occur when it runs beyond its 80% efficiency range. At best, the card will not run at its full potential. At worse, the PSU may died. Use at your own risk.

To answer your other question, yes and no. You have 20A available at each rail. But you don't have 40A total. The max load for the +12V rails is listed as 360W. (360W÷12V=30A) You can't go over a total of 30A.