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PSU advice needed

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August 4, 2009 7:18:00 PM

Ok, so the rig looks like this:

i7 920 - looking at a modest overclock to about 3,5ghz
3x2gb 1600mhz corsair
2x sapphire vapor-x 4890 - quite power hungry, and looking at a modest oc also
NEC AD 7240S, DVD±RW
EX58-UD4P
HDD WD 1Tb, 1001FALS , SATA II
scythe mugen 2 cpu cooler
CM 690 case.

So my first choice was a corsair tx series psu, but for some reason that series psu and the vapor-x card don't work properly (I've looked it up, some peopla are having the same probs with that combo).
The 1000w HX corsair is just too expensive for me atm and i don't know if the 620 hx would pull it off.
So help me out here, what PSU do you suggest?

Another offtopic Q, would 2x xfx 4890 xxx (factory oc-ed to 900mhz) and a scythe musashi cooler fit in the CM 690 without issues?

Thanks alot!

More about : psu advice needed

a c 121 ) Power supply
August 4, 2009 8:45:52 PM

With your specs, and assumptions about fans and other minor stuff, the PSU calculator at http://www.extreme.outervision.com/PSUEngine comes up with only 525W for that build. You'll need 4 PCIE power connectors though.
Try this one: Antec TruePower New TP-650 650W Continuous Power ATX12V V2.3 / EPS12V V2.91 SLI Certified CrossFire Ready 80 PLUS BRONZE Certified Active PFC Power Supply - $120
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
a b ) Power supply
August 4, 2009 10:45:18 PM

He has 2x HD4890s jtt, i think a minimum of a 750w or 850w would be better. I would probably go with the Corsair 850w for $120 after rebate. He'll be using well over 500 watts at load with an overclocked i7 920. So 750w minimum, since this will be a long lasting gaming rig and it's not going to be long till the HD5870s are out, i'd get some headroom.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

If for some reason 2 Sapphire Vapor-x GPUs have problems with Corsair power supplies, i'd blame the GPUs before i'd blame the Corsairs.

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a c 121 ) Power supply
August 5, 2009 12:16:20 AM

I put those assumptions into the PSU calculator (including the pair of 4890s and the 3.5GHz OC), but there's no arguing with a little headroom. He was also concerned about cost, but a 750W version of the TruePower New isn't much more, and has all the necessary connectors.
Is it possible that the rail distribution is what causes the problems with those cards?
August 5, 2009 12:53:43 AM

Most folks recommend running a PSU at between 40% and 60% of maximum capacity. While a good PSU can run at the maximum value, they will be wasting a lot of energy as heat. So your 525W figure, using the less conservative 60% target, indicates an 875w PSU. I would settle on the HX850 and call it even. :) 
August 5, 2009 10:12:57 AM

I know that Corsair is a great manufacturer and looks like the vapor-x series is the only card that has a problem with the TX series psus ( it works with hx and vx), so i think i'll be looking into other 4890 cards to find a good solution since the shop im buying in doesn't have a great selection of psus (they have all the tx series and just 620w and 1000w hx).
Now i just need to find a good vga cooler that can fit well enough with 2x 4890 into the CM690 :)  (or last resort order the psu online).
Anyways thanks for the help guys!
a b ) Power supply
August 5, 2009 3:14:43 PM

minko said:
Ok, so the rig looks like this:

i7 920 - looking at a modest overclock to about 3,5ghz
3x2gb 1600mhz corsair
2x sapphire vapor-x 4890 - quite power hungry, and looking at a modest oc also
NEC AD 7240S, DVD±RW
EX58-UD4P
HDD WD 1Tb, 1001FALS , SATA II
scythe mugen 2 cpu cooler
CM 690 case.

So my first choice was a corsair tx series psu, but for some reason that series psu and the vapor-x card don't work properly (I've looked it up, some peopla are having the same probs with that combo).
The 1000w HX corsair is just too expensive for me atm and i don't know if the 620 hx would pull it off.
So help me out here, what PSU do you suggest?

Another offtopic Q, would 2x xfx 4890 xxx (factory oc-ed to 900mhz) and a scythe musashi cooler fit in the CM 690 without issues?

Thanks alot!


IMHO, it's nothing short of foolish to scrimp on a power supply. It's the cheapest insurance policy you will ever buy for the sucess of your new machine and will probably pay dividends for years to follow. Buy the highest wattage you can afford. Scrimp somewhere else.
a c 121 ) Power supply
August 5, 2009 10:47:13 PM

No, not the highest wattage, the highest QUALITY (of sufficient wattage). I'll take my SG-650 over a 1100W Apevia Warlock any day of the week, unless I need something for target practice.
August 6, 2009 1:11:41 AM

If you are budget limited, drop the 2nd video card and put the cash in your psu (pss, the corsair) to prep your system to be ready when you get more cash to get the 2nd video card.

A fast car with no tires will get you no where...
!