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Best modular psu under $80?

SeductivePig

Senior member
Dec 18, 2007
681
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I have a 2500k, Z68 mobo, 2 harddrives, 8gb of ram, dvd drive, and will eventually be getting two 6870's, most likely this xfx: http://www.newegg.com/Product/Produc...82E16814150521

I was looking at this antec 550W and I was wondering if it has enough amps on it's 12v rail and if it has enough watts, and enough connectors for my setup? It's $68 shipped.
http://www.newegg.com/Product/Produc...82E16817371016

If that's not good enough, what's the best non modular power supply for my build in that price range?
 

lehtv

Elite Member
Dec 8, 2010
11,897
74
91
Don't skimp on the PSU. Power quality, efficiency, heat output and fan noise all get worse as the PSU approaches its rated wattage. By what factor they get worse depends on how good quality PSU you're dealing with.

As a rule of thumb it's a good idea to go for a PSU that will not go above 70-80% of its rated wattage under any circumstances. For your system, that would mean a 650W-750W PSU. Even 850W wouldn't be overkill if you game alot, it'd just keep the load wattage closer to 60% instead of 70-80%, which would maintain efficiency at an optimal level.

If your budget is really strict, I'd recommend forgetting about Crossfire and going for a single 6950 2GB (e.g. this if you're really into XFX's warranty). This would allow you settle for a decent 500W+ PSU, or invest into a more capable PSU that you could use for later, more power hungry systems as well. E.g. 750W to allow crossfiring the 6950 later if needed.
 
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Termie

Diamond Member
Aug 17, 2005
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www.techbuyersguru.com
I have a 2500k, Z68 mobo, 2 harddrives, 8gb of ram, dvd drive, and will eventually be getting two 6870's, most likely this xfx: http://www.newegg.com/Product/Produc...82E16814150521

I was looking at this antec 550W and I was wondering if it has enough amps on it's 12v rail and if it has enough watts, and enough connectors for my setup? It's $68 shipped.
http://www.newegg.com/Product/Produc...82E16817371016

If that's not good enough, what's the best non modular power supply for my build in that price range?

That Antec is a fine PSU, but with 37 combined amps on the 12v rail, it's not even close to sufficient to power 6870 crossfire. Don't bother with it. You are building a premium rig, buy a premium power supply. You can't get a good modular PSU for under $80.

If you seriously can't spend more than ~$80 on a PSU (and I'd suggest you reconsider that limit for this kind of rig), you could go for this PC Power and Cooling (OCZ) 750w unit for $79 after code/rebate: http://www.newegg.com/Product/Produc...82E16817703027.

It's non-modular, but with 62 amps on the 12v rail, it would be plenty for 6870 crossfire.

Even better would be this very fine Corsair 750w unit for $95AR: http://www.newegg.com/Product/Produc...82E16817139021. Better quality than the OCZ-owned PC Power&Cooling. You can read why here: http://forums.anandtech.com/showthread.php?t=2084101

There's also a great deal on the 650w Corsair going right now: http://forums.anandtech.com/showthread.php?t=2185936. It only has two PCIe power plugs, so you'd need to run adapters for dual 6870s, but it probably has enough power (53w on the 12v rail) to run the 6870s.
 
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Skott

Diamond Member
Oct 4, 2005
5,730
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I was looking at this very same Antec BP550 unit for a single 6870 budget build. I would think it would handle that well enough but I'm curious if it how much of a single GPU it would handle down the road if the owner wanted to upgrade the GPU as time went on? It should be enough to handle any single GPU that exists now shouldn't it? Normally I swear by Corsair but their modular units are considerably more expensive.
 

Termie

Diamond Member
Aug 17, 2005
7,949
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91
www.techbuyersguru.com
I was looking at this very same Antec BP550 unit for a single 6870 budget build. I would think it would handle that well enough but I'm curious if it how much of a single GPU it would handle down the road if the owner wanted to upgrade the GPU as time went on? It should be enough to handle any single GPU that exists now shouldn't it? Normally I swear by Corsair but their modular units are considerably more expensive.

It's fine for any single GPU, although I'd probably step up if you were ever going to go with a GTX580-class GPU, which draws almost as much power as crossfired 6870s: http://www.anandtech.com/show/4008/nvidias-geforce-gtx-580/17.