PSU Advice

[FrazzleMcV]

Just wondering, I'm looking to build an i5 sandy bridge system for gaming
I also intend to have an ssd and set of 4 hard drives in raid 10, would a 700 watt psu be suitable for this.

I've tried a number of websites that give calculations but I'm not sure which ones to trust.

Sorry if I've missed any posts about this before.

 

[Hastibe]

What do the calculators say, and which ones have you tried?

 

[eloric]

Adequacy of a 700 W PSU depends on several factors starting the the quantity and type of graphics cards. If you are going to run quad GTX 480s in SLI, then no. If you have a single GTX 460, then 700 W is too much.

Next is an estimate for overclocking. Are you buying a k version of Sandybridge? The power supply calculators do not have the current 1155 sockts yet, so this is a bit tough. I have been selecting instead an i5-760, with overclock settings of 4000 Mhz and 1.45 v. That is a high estimate since the Sandybridge architecture uses less power.

Another big factor is how do you operate your systems - do you keep them on 7X24, running folding programs in the off hours, or use them for an hour and shut them off? This is reflected in the last question for capacitor aging - PSU's wear out, so you need to buy excess capacity for them to last long enough. I figure an extra 25 percent for my power supplies.

If you get those three things right, you will be pretty accurate. SSDs take almost no power, and 4 hard drives use very little compared to graphics, just plug those into the calculator. The websites are all driven off the same software, and mostly ask the same questions. I use this one for no particular reason: Antec Power Supply Calculator.

You will probalby find that 700 W is excessive. I am recommending 450W to 600W on most builds.

 

[treefrog07]

What about your VGA card(s): makes and models? CD/DVDRX drive(s)? Which make/model 700W PSU are you thinking of? A good quality 650W PSU with Active PFC and 80+ efficiency will handle systems with crossfired 5XXX or 6XXX cards. I've been using a Corsair CMPSU-650TX to run two 4870s, 5 HDDs, a TV tuner card, and an optical drive for several months with no problems.

 

[eloric]

Yip, treefrog, if you use the calculator, your configuration calls for minimum PSU of 508 Watts, which leaves a healthy margin for capacitor aging.

 

[geofelt]

Your psu requirements are almost entirely determined by the graphics cards you plan to use.
It is assumed that you may have a couple of drives, and an OC does not add much.

A good quality 650w unit will power any system which has a single great graphics card, even a GTX580, 6970 OR 5970.

Good quality units come from Corsair, XFX, Seasonic, PC P&C, and Antec to name a few.

Do not go cheap on the PSU.

If you plan on dual cards,(which I would avoid) then you will need more.

 

[FrazzleMcV]

Thanks for the help,
I've already got the psu (it came with a case of a friend who already had one)

It's a coolermaster silent pro.

I'm planning to use either a mid-range or hi-end 6XXX ATI graphics card, I was planning to use dual cards once these were out of date, but given the lack of PCIe x16 for the sandybridges I probably wont now.

The full set of components is (this will change as I'm still building funds)

CPU:
i5 - 2500k

MoBo:
Asus P67 Pro/Delux

GPU:
Anything up from an ATI 5850 or later

Memory:
Corsair vantage DDR3 1600mhz

Drives:
DVD RW
BluRay RW
Soundcard (to be added at some point but not a major concern)
Netgear pci wireless adapter

The computer itself will probably only be on when in use, not really any over night stuff.

I used the calculator a while back so i can't remember for the life of me which site it was (I used the i5 960 and assumed they were similar after some comparisons of power usage), and it said it would be fine, I just like to have some more human advice as I've never really built one before

Again thanks for all the help.

 

[dalauder]

Get the 650W (quality manufacturer only) and a 6950 unlocked to 6970.

I personally think DDR3 2000MHz is a better choice for versatility and ability to reduce latencies as much as possible.

 

[FrazzleMcV]

Best answer selected by frazzlemcv.

 

[Silvune]

Yes the Cooler Master Silent Pro M 700W is a good power supply and should even be able to power your video card upgrade plans as well.