Power Supply for 6950 Xfire

[OVerLoRDI]

I'm considering selling my 5850 and grabbing a pair of 6950s. My current concern is my PSU. I have a Corsair 650watt that has served my very well, but my gut tells me I would need a beefier PSU for 2 6950s. The question is, how much beefier?

My current system is as follows:

Phenom II X4 940 (not oc'd currently, will be in the future)
6 hard drives (5x 7200rpm, 1x 5900rpm)
ATi 5850

New system would be the same except replace the 5850 with 2x 6950.

eXtreme PSU Calc gives me a recommended wattage of 637. I made the calculate based on 2 5870s, since the 6950 isn't in their app yet.

Newegg PSU Calc recommends 1012 watts.... Now I think Newegg's calculator is a bit extreme so they can sell big PSUs to noobs, so I'm thinking I need something in between.

I am deciding between the Corsair 750 or 850 (maybe I should consider 900+?). I never want to skimp on the PSU, but I definitely don't want to spend too much either.

 

[tomoyo]

6950 has a TDP of about 200w. Add in your other components and I'd estimate 600-650w. Factor in a little overhead and a 750 sounds just about right.

 

[RavenSEAL]

1000w is the safest option

 

[Meghan54]

1000w is the safest option

So would a 1200W unit or a 1500W unit. But all are overkill in his situation....incl. the 1000W you advocate. A good 750W or 850W unit is all he needs.

BTW....what do you mean by "safest?" Just wonder.....given the questionable advice I've noticed you giving. (A 120Hz monitor will "fix" microstuttering from video cards.....LOL!!!)

 

[RavenSEAL]

So would a 1200W unit or a 1500W unit. But all are overkill in his situation....incl. the 1000W you advocate. A good 750W or 850W unit is all he needs.

BTW....what do you mean by "safest?" Just wonder.....given the questionable advice I've noticed you giving. (A 120Hz monitor will "fix" microstuttering from video cards.....LOL!!!)

A good, quality 1kW PSU will give him:

#1: Better reliability
#2: a future proof unit in case he wants more.

 

[tomoyo]

Unless he's smart and doesn't try to get video cards that suck too much power. Course I prefer being in the under 250w total power range personally, no matter which generation. Also reliability has absolutely nothing to do with the max wattage on a psu.

 

[Mistwalker]

If you're going Corsair then you can easily get by with a 750 with no worries whatsoever, as the units are quality.

The only reason I'd recommend 850 is the PSU remains quieter (lower load percentage at the same wattage), for future upgrades, or if you plan to OC the 6950s hard.

Obviously the OP could buy a 1000W or higher for "future proofing" but he also states he doesn't want to overspend. For a 6950 CF setup it's completely unnecessary.

 

[OVerLoRDI]

If you're going Corsair then you can easily get by with a 750 with no worries whatsoever, as the units are quality.

The only reason I'd recommend 850 is the PSU remains quieter (lower load percentage at the same wattage), for future upgrades, or if you plan to OC the 6950s hard.

Obviously the OP could buy a 1000W or higher for "future proofing" but he also states he doesn't want to overspend. For a 6950 CF setup it's completely unnecessary.

I think I'm going to go with the 850watt corsair. Hopefully video cards don't get that much more power thirsty over the next few years and I can hold on to it through another upgrade cycle.

Thanks for your input guys.

 

[deimos3428]

Good choice. You don't "need" 850W, but they're at a really good price point right now. Going up from a 650/750 won't strain the pocketbook very much, so you may as well.

 

[bigsnyder]

Going too big might also land you the least efficient solution, regardless the specs. Your power consumption might fall outside of the power curve where the unit is most efficient.

 

[BTRY B 529th FA BN]

FurMark always gives you the "worst case scenario" when monitoring wattage draw.

Why don't you simply get a wattage checker from Lowes or Home depot for ~ 20$ and see what are currently drawing from the wall. I did. My i7 @ 3.3Ghz and 2 5870's running UT3 drew close to 300w (total machine power) adding those other HDD drives you have i'd say they probably add round another 20-30w...

Here, here's one from New Egg for 16$
http://www.newegg.com/Product/Produc...-001-_-Product

 

[pugh]

So would a 1200W unit or a 1500W unit. But all are overkill in his situation....incl. the 1000W you advocate. A good 750W or 850W unit is all he needs.

BTW....what do you mean by "safest?" Just wonder.....given the questionable advice I've noticed you giving. (A 120Hz monitor will "fix" microstuttering from video cards.....LOL!!!)

+1

I'm with you on that, I like to search out information I need myself instead of depending on someone else's opinion. Wonder if he would then say you need 1500w psu for 2x gtx580.....

 

[BTRY B 529th FA BN]

I took out those 5870 cards, and running 1 GTX 480 and the i7 @ 3.49Ghz playing UT3 runs around 255w power draw from the wall.

 

[OVerLoRDI]

What is the general opinion of Thermaltake PSUs? Quality wise how do they compare to Corsair? I'm considering this:

http://www.newegg.com/Product/Produc...82E16817153106

 

[BTRY B 529th FA BN]

What is the general opinion of Thermaltake PSUs? Quality wise how do they compare to Corsair? I'm considering this:

http://www.newegg.com/Product/Produc...82E16817153106

IMO - dislike

my favs and top tier 3- Seasonic, Corsair, Enermax

The Seasonic X - 650 and 750 are phenomenal PSUs in terms of clean power, great ripple suppression, and efficiency. I personally own the 650 model.

EDIT: btw, I am selling my Enermax Revolution 950w for 170$

 

[jacktesterson]

My xfx 850 is 9.6/10 on guru and runs my similar rig just fine at 4.2

It's a seasonic made modular psu. I got mine for around 130 on sale

 

[OVerLoRDI]

http://www.newegg.com/Product/Produc...82E16817151100

So this would be a wise choice then?

 

[BTRY B 529th FA BN]

Not when the Seasonic X 650w is going for 129$

 

[jacktesterson]

http://www.newegg.com/Product/Produc...82E16817151100

So this would be a wise choice then?

Thats a great no frills psu.

 

[BTRY B 529th FA BN]

This is where the Seasonic X 650w gets interesting. Read this review:

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story2&reid=169

 

[TemjinGold]

OP: Since you already HAVE a Corsair 650, why don't you actually plug it all in and use it for a while first? If the thing starts running out of power during usage (HIGHLY doubt it), THEN go spend your money on a bigger PSU. Most people think they need far more PSU than they really do. You really don't have anything to lose here because the worst that can happen is a game crashes because you didn't have enough juice. As long as your 650 isn't malfunctioning, you should be fine with it.

 

[flopper]

750w corsair running highly overclocked. all is well.

 

[Face2Face]

OP: Since you already HAVE a Corsair 650, why don't you actually plug it all in and use it for a while first? If the thing starts running out of power during usage (HIGHLY doubt it), THEN go spend your money on a bigger PSU. Most people think they need far more PSU than they really do. You really don't have anything to lose here because the worst that can happen is a game crashes because you didn't have enough juice. As long as your 650 isn't malfunctioning, you should be fine with it.

+ 1

 

[Elfear]

In case you haven't gotten a PSU yet OP, I just ran the STALKER:COP benchmark with the computer in my sig (6950's unlocked at stock 6970 clocks) and peaked at 720W from the wall plate. If my efficiency is ~85%, then my system needs ~612W. With the cards overclocked I'll bet it would be easy to hit 800-825W from the wall plate (~680-700W system draw). Sticking with the 30% buffer rule being thrown around you would need a 1KW PSU.

I can't even imagine a quad 6970 or tri SLI 580 system.

 

[BoomerD]

http://www.newegg.com/Product/Produc...82E16817151100

So this would be a wise choice then?

Good, but for the price, I'd go with one of these:

http://www.newegg.com/Product/Produc...82E16817207003

http://www.newegg.com/Product/Produc...82E16817207001

Both get excellent ratings from JonnyGuru. (9.6, 9.7)