Powering two HD4850s

[Mansin]

I'm building a new PC now, and am upgrading to two 4850s when I can afford it. I'm looking at power supplies and am wondering what's better for them

4 12v rails at 18A
or
3 12v rails at 19A

Basically, total amps or amps per rail?


Also, I'm looking at Rosewill power supplies, which I've never heard of, but are retarded cheap for their power. Are they some off brand garbage I should stay away from?

[Olo401]

Rosewill are horrible. As far as PSUs go, the ones to look at are PC Power & Cooling, Corsair, Thermaltake, Seasonic, and the higher-end Antec and Cooler Master units.

(NOTE: This next part I'm winging it on. I'm not a real expert on power & electricity. just guessing based on what I know from my own reading. If any of this info is bad, PLEASE post a correction!)

The number of rails goes more to the efficiency of the unit than how much power it's rated for. Most PSUs on a single rail should be fine, but for power output you want to go for higher wattage. In your case, for a double-GPU setup, I'd recommend at least a 650 - or if you get a double rail you'll want at least 4-500 per rail.

[Luciola]

Also, I'm looking at Rosewill power supplies, which I've never heard of, but are retarded cheap for their power. Are they some off brand garbage I should stay away from?

You dont go and spend $500 on 2 new video cards just to have them fried by a cheap ass no name power supply. Just because they are cheap and supply a particular voltage, it doesnt mean they are stable under load. Ive had the misfortune of repairing a computer with one of those psus. Video card, motherboard, blu-ray burner and ram were all fried from 1 capacitor blowing and shorting out nearly everything else. It was one smelly mess... Dont EVER buy them!

[Stromgarde]

I got this Rosewill 500W PSU and haven't ever had any problems with it. However, it may just be that mine is an isolated example of competence... are Rosewill really that bad?

http://www.newegg.com/product/produc...82E16817182059

[rezn0r]

Newegg.com - PC Power & Cooling S75QB 750W ATX12V / EPS12V SLI NVIDIA SLI Certified (Dual 8800 GTX and below) CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Power Supplies

[Kohan]

Newegg.com - PC Power & Cooling S75QB 750W ATX12V / EPS12V SLI NVIDIA SLI Certified (Dual 8800 GTX and below) CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Power Supplies

This is a good suggestion. As aforementioned, do not skimp on the power supply. It's where an unfortunately large amount of people try to save some dollars, and is one of the worst parts for cutting costs on. The energy that you'll be taking in through the PSU is going to touch every last part within your machine, so why would you risk the lives of those components?

More rails can be good, but your primary concern is overall performance, and the PC Power & Cooling line is magnificent.

Another possibility: Newegg.com - Antec TruePower Quattro TPQ-1000 1000W ATX12V / EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Power Supplies

[Olo401]

I got this Rosewill 500W PSU and haven't ever had any problems with it. However, it may just be that mine is an isolated example of competence... are Rosewill really that bad?

Newegg.com - Rosewill RP500-2-S 500W ATX12V v2.01 Power Supply - Power Supplies

They're all probably made in the same three Chinese factories and just badged differently... lulz

Or then again... yep looks like there's three factories on the list that make Rosewill PSUs. Interesting list.

[Shuemue]

Buy this, it's so fucking sexy, Newegg.com - CORSAIR CMPSU-620HX 620W ATX12V v2.2 and EPS12V 2.91 SLI Certified CrossFire Ready 80 PLUS Certified Modular Active PFC Power Supply - Power Supplies

Modular ftw

[Mansin]

I can only spend $100~ more, so it's between this or a used True Power Trio.

http://www.newegg.com/Product/Produc...82E16817341002

[Shuemue]

Then stretch to this; Newegg.com - CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Power Supplies