How much power do I need?

Varone · 21 Dec 2007 at 18:43

Antec P182B
Intel Core 2 Duo E6750 Conroe
Asus P5K Premium (TBC)
4GB (4x1) Corsair PC2-8500 Dominator
2x BFG 8600GTS OC2 256MB (720Mhz)
150GB Western Digital Raptor X
400GB Western Digital Caviar

Originally I was going to opt for a single video card and so a 530w PSU seemed fine but I recently decided to going for a couple of 8600GTS' and am concerned that the power drain will be too high. I haven't gone for a dual card setup before so any help would be appreciated.

A specific PSU recommendation would be nice too, but it will need to fit in that cage on the P182 and be relatively quiet.

Tetras · 21 Dec 2007 at 18:46

I recently decided to going for a couple of 8600GTS

Why why why?

Good PSU in 500+ model range should be fine. Corsair HX520 for example....

fobose · 21 Dec 2007 at 18:52

Using this:

http://www.extreme.outervision.com/PSUEngine

Your spec requires a 359W PSU, that was with the additon of 8 usb devices, TV card, sound card, 4 120mm fans and 2x DVDRW.

Varone · 21 Dec 2007 at 18:53

The benefits of an extra 256mb in a single card on the 8600GTS made no difference to performance but a second card both running at 720Mhz, and 256mb on each card running at 2200Mhz seemed like a good idea. For under £250 on cards it seemed like the best option. Do you beg to differ?

Hxc · 21 Dec 2007 at 18:54

http://www.overclockers.co.uk/showproduct.php?prodid=GX-051-OK

£2 over but it'll smash those two.

willhub · 21 Dec 2007 at 18:56

Varone said:
The benefits of an extra 256mb in a single card on the 8600GTS made no difference to performance but a second card both running at 720Mhz, and 256mb on each card running at 2200Mhz seemed like a good idea. For under £250 on cards it seemed like the best option. Do you beg to differ?

And when you run 2 8600GTS's in SLi its still limited by 256mb of memory.

For £150 or even -110 you could have got something from a 3850-8800GT and get better performance.

fobose said:
Using this:

http://www.extreme.outervision.com/PSUEngine

Your spec requires a 359W PSU, that was with the additon of 8 usb devices, TV card, sound card, 4 120mm fans and 2x DVDRW.

Power calculators are rubbish.

fobose · 21 Dec 2007 at 18:56

I am pretty sure a 8800GT would beat those 2 aswell?

Hxc · 21 Dec 2007 at 18:56

More than likely, I just posted to the top of the budget.

PinkPig · 21 Dec 2007 at 18:57

Getting 2 8600s is a terrible idea. A single card will give you much better performance for the same money.

willhub · 21 Dec 2007 at 18:58

fobose said:
I am pretty sure a 8800GT would beat those 2 aswell?

8800GT beats a 3850 by a long way, it beats a 3870 aswell, and will deffenitly beat 2 8600's too.

Ben M · 21 Dec 2007 at 18:59

PinkPig said:
Getting 2 8600s is a terrible idea. A single card will give you much better performance for the same money.

fobose · 21 Dec 2007 at 18:59

willhub said:
Power calculators are rubbish.

In the respect they over compensate?

willhub · 21 Dec 2007 at 19:00

fobose said:
In the respect they over compensate?

They seem to overcompensate by a long way.

Varone · 21 Dec 2007 at 19:01

Thanks for the input guys. I think I'll go for that 8800GTX! Is the cooler pretty loud and if so are there any third party improvements?

fobose · 21 Dec 2007 at 19:02

Yes, my point being a 500W PSU for his system is totally OTT.

willhub · 21 Dec 2007 at 19:06

A nice HX520W or HX620W would be good for the system, but a HX520W would power it fine.

Gald to see we all slapped some sense into him and he's getting an 8800GTX now

.

Tetras · 21 Dec 2007 at 21:15

Your spec requires a 359W PSU, that was with the additon of 8 usb devices, TV card, sound card, 4 120mm fans and 2x DVDRW.

Yes, my point being a 500W PSU for his system is totally OTT.

Aside from the +12v rails being far more important than any calculated wattage, it is very unwise to run a PSU near to rated capacity (heat, efficiency, noise, voltage regulation & component stress). That isn't mentioning that not many PSUs are actually capable of sustaining a load at or near their rated wattage.

Assuming you left some extra output capacity on the 359 from the calculator and the OP had no intention on overclocking or upgrading to a more power-hungry graphics card / PC in the future that would make a 400 Watt PSU. Perhaps now 500 range doesn't sound such a waste?

~>Dg<~ · 21 Dec 2007 at 21:31

any decent 500w will do and give you a little scope for future upgrade.

james.miller · 21 Dec 2007 at 21:33

Tetras said:
Aside from the +12v rails being far more important than any calculated wattage, it is very unwise to run a PSU near to rated capacity (heat, efficiency, noise, voltage regulation & component stress). That isn't mentioning that not many PSUs are actually capable of sustaining a load at or near their rated wattage.

Assuming you left some extra output capacity on the 359 from the calculator and the OP had no intention on overclocking or upgrading to a more power-hungry graphics card / PC in the future that would make a 400 Watt PSU. Perhaps now 500 range doesn't sound such a waste?

my old pc drew about 330w at the mains full tilt. thats an 8800gtx and a 3.2ghz e6600 by the way. how much power do you think he needs?

Tetras · 21 Dec 2007 at 21:54

how much power do you think he needs

As I said in my first post I think a decent PSU in 500+ model range would be sensible. Your PC would have been sucking most of that out of the +12v rails and even if we take a PSU universally(ish) recognised as decent, the VX450, it is only rated up to 33A / 396 Watts.

http://www.corsair.com/products/vx.aspx

Yes a 400 Watt PSU would run in the short-term but I don't think it would be leaving enough headroom and end up running harder than I'd be comfortable with (especially considering PSU is an investment that will potentially last through several rigs / upgrades).