Need help please. Psu for 4870 CF specifically.

[CreasianDevaili]

Sorry to be a bother.

I was wondering if a Silverstone ST56ZF psu, 560w with single 12v rail 38amps, could handle the 4870 Crossfire setup with the following PC components:

e8400 3.825Ghz using Zalman 9700LED, x38-DS4, 2x1gb XMS 2 DDR2-800, 1 WD SE16 Sata HDD, 1 DVD/CD burner combo SATA, 4x120mm fans +4x120mmLED fans.

I am very doubtful, as i would have to use 2 molex adapters for the 2nd card. I wont want to kill my psu as i am putting it in a older machine. Was going to get the HX1000 and a single 4870 but i am wondering if i can just get the 2 4870's and CF tem without it.

Be frank with me. I am not wanting to kill the psu, or the new gpu, or anything else if the psu gets overloaded. Not worth it. I know people have done the this on a corsair 620w but every psu is different, and that was a multi rail vs my single. So its not apples to apples really and I am asking advice on it.

Can get a 4870 and hx1000 psu today, since the psu is for going to nehalem next year and i like to OC, or get 2 4870's if my current psu can handle it and get the hx1000 in september.

Since i game at 1920x1200 i dont think i need to wait for a 4870x2.

Thoughts?

 

[vgkarthik88]

if ur going to upgrade to a hx1000 anyway you might as well do it now. also 4870 is a power hungry card. you also mention you like to OC and that will def suck up more power. if ur stick with this, expect some crashes while OCing. also, your getting 4870 CF to play at 19x12. why dont u want to wait for 4870X2? u can get the same GPU's same memory for $100 less. i know some people will say performance will not be the same but its def worth it if the price is cheaper. with 4870 selling so well prices may not drop soon.

 

[BTRY B 529th FA BN]

what i don't understand is how one can tell if the psu isn't enough

 

[HumblePie]

Umm, from AT's review, it looks like 4870's in CF pull about 200 to 225 watts at load. That plus an average 150w CPU a 10w per HDD at load, and 40w for a good mobo, and a fe wmore here and there for case fans and what not and you'll know how much you need.

Look up the test rig system specs he was using and the 4870's in CF were using 420ish at load.

 

[chizow]

Originally posted by: BTRY B 529th FA BN
what i don't understand is how one can tell if the psu isn't enough

In actual application? You try to power up and nothing happens. Or you turn on the power, start to POST, then power shuts off. Or you're in the middle of gaming and your PC suddenly shuts down/restarts. Or worst case....you smell smoke.

I'd say 560W is pushing it no matter how good the PSU-maker is. You can try over in the Power Supplies forum for maybe a more focused answer.

 

[beray]

Originally posted by: CreasianDevaili
Be frank with me. I am not wanting to kill the psu, or the new gpu, or anything else if the psu gets overloaded. Not worth it. I know people have done the this on a corsair 620w but every psu is different, and that was a multi rail vs my single. So its not apples to apples really and I am asking advice on it.

Let me be frank with you.

99.999999999% of consumer PSUs 800W and under on the planet are 12V single-rail PSUs. The "12V single-rail" PSU experts on the net simply didn't recognize their favorite "12V single-rail" PSUs.

They usually can't recognize their favorite "12V single-rail" PSUs even if you bash their brains out with one.

You should ask your questions in the PSU forum.