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PSU's SLI or large wattage?

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February 8, 2010 12:02:45 PM

Hi there,

I've had a bit of trouble with my newly built computer.

Stupidly I placed a 700watt (20euro) job psu into the computer. Stupidly? yes because Im running a i7 920, asus p6t delux mobo, 4gb gskill ram, 2x 500gb sata/raid 0 drives, Crazy processor cooling pipes with a 140mm fan + stupid blue led's, a nvidia gts 9600 (phys dedicated) and a GTX 260.

So yeah i killed my psu.... but I know shag all about them and now its all rails this and sli that.

I just want a nice cheap solution if possible.

Ive been looking at the Corsair HX1000W but to me it seems a bit overkill for my setup. Should I just go for a bigger wattage like a 900w? Or am I better going with something "future proof" if i decide to get another gtx260.

any ideas??

Cheers in advance!

More about : psu sli large wattage

a c 84 B Homebuilt system
February 8, 2010 12:12:38 PM

You don't need that much wattage. You probably just bought a poor quality unit. Stick to Corsair, Antec Earthwatts, FSP and SeaSonic to ensure you get a good unit.

Check out a decent PSU wattage calculator to decide how big of a unit you need. The Guide to Choosing Parts has a link to a decent calculator.
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February 8, 2010 12:23:46 PM

Sweet! Nice one lads going to take a look now!

And hey ares1214 whats up with having 4gb with an i7?
a c 84 B Homebuilt system
February 8, 2010 12:27:09 PM

The i7-920's boards use triple channel memory. That means you need 3 sticks of RAM to get the best performance. 4 GB is dual channel. Using dual channel RAM makes the RAM operate slower than if it was triple channel. Thus, the computer is a little slower than it could be.

It's not a big problem, but it's a pretty big oversight that would have only added anouther $50-75 to the build.

I would look into if you can another stick of the EXACT same RAM to add to make it work to the full power of the build. If you can't, keep it in mind when you upgrade the RAM later and buy two 2x2 GB kits of what you've got now, for a total of 12 GB.
February 8, 2010 12:30:36 PM

hahaha ok, mad I didnt realise that. I actually got 6gb but I only use 32bit systems so I just went with 4 like the older systems.

Cool, nice one man, a bit more reading for me to do so!
February 8, 2010 12:40:23 PM

why did you only get 32??? but yeah max of 32 bit is like 3.2-4 gigs, then you would think the max of 64 bit is 6, but its actually like 256 terrabytes lol.
a c 84 B Homebuilt system
February 8, 2010 12:42:53 PM

It's actually ~3.75 GB. And the large increase is because the way tech works is that everything advances at an exponential pace.
February 8, 2010 12:47:56 PM

right, although its different by computer for some reason, some recognize 3.2, some 4, so i just said somewhere in between. haha can you imagine 4x64 Tb ram sticks haha, now thats a ram upgrade :lol: 
February 8, 2010 8:22:21 PM

haha

Recommended PSU Wattage: *595 on Thermaltakes Power Supply Calculator

where in the jaysus was i going with 1000w!?
February 8, 2010 8:43:08 PM

lol you may think that, but the computer needs ac wattage, and the 1000 watts is dc wattage. this is where the efficiency comes in...say that 1000 watt psu has a efficiency of 80%, then it would convert 1000 dc watts into 800 ac watts, converting the extra 200 into waste and heat. of course the 1000 is overkill since 800 is way more than you need, but if you ever want crossfire, and say you bought a 700 watt psu @ 80%, then it puts out 560 ac watts, which would be enough power, but probably wouldnt be enough for a crossfire, depending on a lot of factors...sooooo i wouldnt go less than 800, and mosts psus are at 850, which is perfect for you :) 
a c 84 B Homebuilt system
February 8, 2010 10:10:47 PM

ares is basically right about the efficiency, but he's going the wrong way. The wattage on the PSU is the maximum it can supply to the PC, not how much it can draw.

Say you require that 595W to run the computer. If the PSU was 80+ Certified (greater than 80% efficient at all loads), it would need about 745W from the wall to supply that. The extra 150W is released as heat, which causes the unit to wear out faster. A 600W PSU could still power the system, despite needing more than 600W coming in.

Efficiency is a separate matter from size. Typically, the larger the PSU, the more efficient. In addition, a unit is more efficient when its at close to 50% load. Higher or lower makes it less efficient.

Keep in mind that the calculator determines everything at max load, and depending on the calculator, may or may not take into account aging. Some also state how much wattage is required and some state how much is recommended. That can often be a big difference.

All of that said, if you weren't planning on overclocking or SLI/Crossfire in the future, a 650W would be big enough. If you want to do either of those, a 750W is good. If you want the option to do both, get an 850W. Just make sure that it's at least 80+ Certified, ideally at least 80+ Silver.
February 8, 2010 10:34:52 PM

right, same number, different way of thinking about it lol :lol:  but yeah, i would def get either the ocz gold modualr 850 (above 90% at all times) or the corsair 850 watt (above 85% i believe), both of those are high quality, high efficiency, and tons of options...
February 9, 2010 11:26:09 AM

sweet, its funny I've never had to look into this before. Its the first system I've built in about 12 years ....... ah back in the voodoo 2 and quake days.

Ok so judging on what you guys are saying go with 850. I'll obviously do a bit more research on it just to make sure i can go with sli in the future.

At the moment all i need is the gtx260 really but the gt9600 I was dedicating to physx just because I could.

So this wastage of power you guys are talking about is that not controlled by my mobo? The asus p6t has software to control that i thought no? or hows it work?

Again thanks a million lads!
a c 84 B Homebuilt system
February 9, 2010 11:31:29 AM

It's not so much that the power is wasted, it's that you're wasting your money buying extra headroom that you'll never use. If you only need 850W, but buy a 1000W unit, you're wasting the premium you paid for the extra 150W.
February 9, 2010 11:35:15 AM

right, its not like you make the watts less powerful and use them, its that you only use about 800 watts of that, not using the full power of it, so you waste your money...
February 9, 2010 11:35:57 AM

ok makes sense. haha and by god theres a massive price difference! yay im not going to be totally smashed for cash now!

Lads thanks for that, i'd buy ye a guinness in the pub if i could!
!