Will 850W PSU be enough for GTX 285 SLI?

affinitydesigns

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I'm looking to get an SLI configuration.
At the moment I'm deciding to get either two GTX 260 Core 216 or a single GTX 285 and get another a month or two down the road.
1. Is the 260 or 285 better for the money?
2. Will the 850W PSU run both SLI set-ups?
3. Will the 850W PSU run a tri-SLI 260?
4. If yes to 3, Would that be better than a two SLIed 285s?
5. Can the Asus P6t Deluxe V2 Do a tri-sli?

Here's my proposed system.

i7 920
Asus P6t Deluxe V2
Kingston HyperX 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 2000
Western Digital Raptor WD740ADFD 74GB 10000 RPM / Western Digital Caviar Black WD1001FALS 1TB 7200 RPM
CORSAIR CMPSU-850TX 850W ATX12V 2.2 / EPS12V 2.91 SLI Ready

I was talked out of a CORSAIR CMPSU-1000HX 1000W ATX12V 2.2 / EPS12V 2.91 which I know could run the two 285s, but I don't know about the three 260s.

I plan to get these components first and then get water cooling after.

Thank you for your help.
 

n3f0ur

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1. 260 at $160-ish on sale is the ultimate best bang gpu. If you can find it at that price, snag 2.

2-4. See these:

http://www.slizone.com/object/slizone_build_psu.html
http://www.nvidia.com/object/product_geforce_gtx_260_us.html
http://www.nvidia.com/object/product_geforce_gtx_285_us.html

Doesn't mean other psus won't work. They're not certified yet. Unfortunately, most cards don't list the SLI requirements, but rather, they refer to SLIZONE.

5. Yes. SLI and CrosFireX. Only at x16/x16/x1 or x16/x8/x8 mode.

http://www.asus.com/Product.aspx?P_ID=iRlP8RG9han6saZx
 

n3f0ur

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Not enough room for 3-way sli or Crossfirex if the cards are 2-slot wide. The mobo slot layout is not the best. The 3 shorter slots should be in between the PCI-E ones. Look for another mobo.
 


A 850w psu like a Corsair for example can easily push two gtx 285's and have plenty of juice to spare. It's the ATI cards that suck up the power. Unless your using a 52" monitor with god only knows what resolution, two gtx 285's will pretty much clean house with any game out there atm. Lucky for you the price on those cards has dropped to $300 at newegg.
 

Distinct

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How long do you think this system will last you? If you plan to have this system for a long period of time it might be smart to spend the extra $50. I only say this because technology down the road might suck up more juice, and if you plan to have the system for a while, then you'll be upgrading!
 
I know you only asked for suggestions on the PSU, but I would ditch that old 74GB Raptor drive. The current 7200RPM drives are just as fast as that old Raptor and offer MUCH better price/performance. I would replace the Raptor drive with a 640GB Black Edition drive WD6401AALS. If you really think you need a Raptor, take a look at the VelociRaptors.


Edit: The 850TX will easily power SLI GTX 285's as has been stated above. There's no reason for a 1000W PSU for that build.
 

affinitydesigns

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Thank you for the help guys. Yeah, I've changed my HDD's to two Caviar Black's in RAID 0. I'm planning on using two 22" Samsung HD monitors and I also have a 46" LCD HDTV that I'll probably hook up to a few times a week for presentation and what have you. (I run my own business.)


Edit- I just found the Corsair Power Supply Calculator and I don't know how accurate it really is, but it's suggesting for an OCed i7 and two OCed GTX 285 and 2-4 HDD's to get the 1000W CPU.
 

sassan

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its better to be safe then sorry. But I think the 850W for two sli 285 should be enough.

I don't trust those calculators, just a marketing scheme.

I think it looks for what the person is buying for example an i7 and they suggest a higher priced PSU.

750W should be good, but 850W is recommended.

If you are planning on doing with 3 Way SLI then get the 1000W

This guy is using the HX620 with these specs
http://www.asktheramguy.com/v3/showthread.php?p=396925
 

affinitydesigns

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Wow, well that puts things in perspective.

I have another question for you.

I have an old computer I am upgrading.
It has a 350W PSU which I'm not sure can handle what I want to put into it.
Phenom 9600
Gigabyte MA78GM-US2H
3GB of Ram 2x1GB 2x512MB
DVD-ROM
250GB IDE HDD

I built it all up wired it right, and when I hit power, nothing happens. I've checked a million times to make sure the connections are secure and in the right place, but nothing happens at all. I know the power supply is good because I can plug in a different mobo and it turn it on.

Does that sound like the PSU isn't strong enough?

I don't know if the Mobo is good or not. Any way to check it?
the only PSU I have access to at the moment is the 350W.

I would hate to buy another PSU just to find out that the Mobo is bad.