I need some help with PSU

[DirtyDel]

I used the PSU calculator sticky thread and I think I got false results. Here's the system I'm building-

*I7 920 SLBEJ - which I plan on OC'ing to 3.4 and cooling with a *Thermalright Ultimate 120 extreme 1366 RT Rev.B
*ASUS P6T Deluxe v2
*CORSAIR TR3X6G1600C7D 6GB 1600 DDR3
*CrossFire XFX Radeon HD 4890 XT
*Western Digital WD1001FALS 1TB SATA2 7200rpm 32MB Hard Drive
*LG GGW H20L Super Multi Blue BLU RAY BD-R

After I typed everything into the calculator to the best of my knowledge, it came out to 497W.

That seems a bit low for an overclocked CPU and two graphics cards. Any suggestions? I would love to hear some ideas or what you would buy.

One more question- does anyone think I need a cooler for my video cards?

 

[hitokiri_808]

That actually sounds about right for the actual DC draw. Of course that doesn't mean you should use a 500w PSU though. A 700-850w would be a good wattage range to get to keep the efficiency up and a little room to grow. Seasonic, Corsair, Antec, Enermax, are all good. Read through some other threads in the PSU section to see what everyone else is running.

 

[DirtyDel]

That actually sounds about right for the actual DC draw. Of course that doesn't mean you should use a 500w PSU though. A 700-850w would be a good wattage range to get, to keep the efficiency up. Seasonic, Corsair, Antec, Enermax, are all good.

if i went for a quiet 850, would that damper performance?

 

[RollingThunder]

I used the PSU calculator sticky thread and I think I got false results. Here's the system I'm building-

*I7 920 SLBEJ - which I plan on OC'ing to 3.4 and cooling with a *Thermalright Ultimate 120 extreme 1366 RT Rev.B
*ASUS P6T Deluxe v2
*CORSAIR TR3X6G1600C7D 6GB 1600 DDR3
*CrossFire XFX Radeon HD 4890 XT
*Western Digital WD1001FALS 1TB SATA2 7200rpm 32MB Hard Drive
*LG GGW H20L Super Multi Blue BLU RAY BD-R

After I typed everything into the calculator to the best of my knowledge, it came out to 497W.

That seems a bit low for an overclocked CPU and two graphics cards. Any suggestions? I would love to hear some ideas or what you would buy.

One more question- does anyone think I need a cooler for my video cards?

DirtyDel,

Like that handle!

Anything in in the 750 watt + range in this sticky link placed above in the Power Supply area should do you just fine.

http://www.ocforums.com/showthread.php?t=589708

The 4800 series vid cards aren't "bears" on your system although I haven't seen reliable specs on the 4890 wattage requirements yet. As long as you are speaking two "single" 4890's, it sounds about right. Dual 4870's in CF is about 250 - 275w (not overclocked).

 

[chuck4456]

If you are going to run dual 4890s then you need a high amp single rail power supply.
No brainer there.

 

[DirtyDel]

how's this
quiet corsair 750w
http://www.digitalstormonline.com/product.asp?id=143105

anyone have suggestions on cooling GPU?

 

[DirtyDel]

If you are going to run dual 4890s then you need a high amp single rail power supply.
No brainer there.

can i get a link?

 

[Oklahoma Wolf]

If you are going to run dual 4890s then you need a high amp single rail power supply.

No, you don't. Any good 850W will do, regardless of rail topology.

 

[mjw21a]

I've never seen a review which adequately explains why dual rail would ever be better than single.... Plenty where they rate a PSU lower simply because its not dual rail.

Isn't it just that Intel specifies dual rail for EPS compatibility or something?

I know the wolf will know the answer to this. He is the PSU king

 

[RollingThunder]

I've never seen a review which adequately explains why dual rail would ever be better than single.... Plenty where they rate a PSU lower simply because its not dual rail.

Isn't it just that Intel specifies dual rail for EPS compatibility or something?

I know the wolf will know the answer to this. He is the PSU king

Right in our "Stickies:"

http://www.ocforums.com/showthread.php?t=548862

 

[Oklahoma Wolf]

Each has advantages, each has disadvantages. Pick your poison.

Single 12V disadvantage - if powerful enough, unit's OCP won't shut the unit down in the presence of minor short circuits. Increases chance of physical damage from said short (some of the most powerful single 12V designs you can almost arc weld with, that's how high the OCP trip point is).

Single 12V advantage - can run oddball loads like TEC's or piles of hard drives without worrying about split 12V OCP trip points.

Split 12V disadvantage - if sensitive enough or implemented improperly, the unit will shut down with one too many hard drives or components needing more power than the OCP is set for. Most of these units are not optimized for unusual configurations like 20+ hard drives at once or TEC rigs.

Split 12V advantage - smaller chance of the unit not shutting down in a valid short circuit condition. The OCP remains invisible to the unit until it trips and shuts the unit down, like a household circuit breaker.

The good news is, these days you have to look hard to find good units either split or single 12V that will not run the average rig. Most companies' engineers have wised up after a few companies' exercises in doing split 12V wrong (I'm looking at you, Enhance and PC P&C). Just size them according to your power needs, and you should be just fine as long as you make sure you're getting a decent quality PSU.

Personally, I run split 12V units in both of my rigs.

I've never seen a review which adequately explains why dual rail would ever be better than single

Dual 12V designs usually tend to be smaller units not really intended for demanding rigs. Usually they will be ok for running rigs that won't overdraw their total output rating, but that often amounts to a low end video card or CPU.

Quad and up 12V topology is usually favored for split designs over 600W just because they permit enough design flexibility for the engineers to put connectors where they need to go.

Darn - I meant to do a quick reply and posted an essay. Any more questions, just read the sticky

 

[Aynjell]

If you are going to run dual 4890s then you need a high amp single rail power supply.
No brainer there.

OMGOSH LOL I love that image!

 

[mjw21a]

Hmmmm, cool. So my HX is likely a single and that really means sweet bugger all unless the PSU is too small for my needs

Got ya

 

[Oklahoma Wolf]

Hmmmm, cool. So my HX is likely a single

The Corsair HX's were always single 12V. They pulled out the split OCP even before they hit the market, and after all the labels and literature had already been printed.

 

[mjw21a]

As I nderstand it PSU's lose their capacitance over time also varying depending on component quality. Does anyone know roughly how long a quality PSU should last?

 

[Oklahoma Wolf]

5 years minimum.

 

[mjw21a]

Cool, looks like I've another 3 years with this thing then.

 

[DirtyDel]

i can't find a quiet 850w. is the corsair one good? no one has said anything about cooling my graphics cards.

 

[watchthisspace]

I have a Corsair HX620 and a friend has the Corsair TX750, both are incrediably silent PSU's.

For GPU cooler, what about a couple of these: http://www.frozencpu.com/products/8...ICrossFire_Ready_NVIDIA_ATI.html?tl=g40c21s65

 

[mjw21a]

The Antec Signiture series PSU's are meant to be extremely quiet, even more so the the Corsairs which are quiet power supplies in their own right. Take a look at Silent PC Reviews recommended list: http://www.silentpcreview.com/Recommended_PSUs