Power Supply

mojomonkeyx · 21 Aug 2008 at 10:56

Greetings OcUK forum wizards,

I've been slowly building up a rig from scratch and I'm doing quite well with it. The one thing I'm not so sure about is power, so I thought I'd ask what would be a good power supply for my system.

I currently have a 600W PSU but it has no PCI express connectors so I can't use it with my new graphics card.

Current specs:
Intel Core 2 Duo E8400 @ 3.00 GHz (not overclocked)
4GB Corsair DDR3 1333MHz RAM (not overclocked)
Asus P5E3 X38 Motherboard
2xSATA HDD @ 7200rpm
1xSATA DVD-ROM drive
PCI TV card
4 additional fans

Currently with an old Radeon X300 SE in there so that I could set up Windows, a power meter shows the drain as constantly below 200W on load, and idles at around 120-130W.

The plan is to put a Radeon HD 4870 X2 in there, which I know is a beast for power consumption. I would also like to have the option to upgrade the CPU, add a VelociRaptor and possibly in the very long term add another X2 to crossfire.

Back in my day I know a 900W PSU would run a 4 GPU solution, but it appears times have moved on!

Any advice on:
-a budget PSU that will run the above rig along with the single 4870 X2
-a PSU with room for my specified upgrades
-is a modular PSU worth getting simply so that my case is tidier (I'm running an air cooled system)

Thanks for any help, appreciated!

mojomonkeyx

Pilky01 · 21 Aug 2008 at 13:16

http://www.overclockers.co.uk/showp...2.2 Modular SLI Compliant PSU (CMPSU-1000HXUK)

CLAIMED as well

AbsenceJam · 21 Aug 2008 at 13:49

A CF'd 4870X2 system like that would draw around 675w from the PSU by my reckoning, so you could get away with 850 but since most 1000's are in the same range and will have their fans spin up later you might as well. The Zalman got an excellent review at SPCR (one of the few good sites for PSU reviews) - http://www.silentpcreview.com/article834-page1.html .

EsaT · 21 Aug 2008 at 14:20

If you have big case with lot of empty space near PSU you can easily bundle unused cables there but in other situations modular cables definitely help lot.

4870X2 apparently peaks around ~200W, E8400 peaks at ~30W and we're around 300W peak draw. (for fast quad core I would add 50W)
Unless you need additional heating or play benchmarking most benefits from second card might go to power company.

mojomonkeyx said:
Currently with an old Radeon X300 SE in there so that I could set up Windows, a power meter shows the drain as constantly below 200W on load, and idles at around 120-130W.

Sound like old low efficiency design or power meter tumbling to non-sinusoidal/phase shifted current.
Does it even have name and specs?

Back in my day I know a 900W PSU would run a 4 GPU solution but it appears times have moved on!

Cooler Master had a demo up and running of two systems powered by a single power supply; and in all fairness, Foxconn had one of four systems powered by one power supply, but the difference between the two is that Cooler Master had a two quad-SLI system...
http://www.fudzilla.com/index.php?option=com_content&task=view&id=7772&Itemid=38
Messing card model in here but better pics of system.
(also X2 cards are actually two GPUs in CF)

Guardsmon · 21 Aug 2008 at 14:29

The Corsair listed above would be a good choice for what you are hoping to finally put in your system.
You ask for advice on a budget PSU - don't buy a budget CPU unless you have the money to rebuild the rig over again.

If you really are going to put 2x 4870x2's in there then you'd do better getting that corsair now and buying other things later. Otherwise if you're not worried about the 2nd 4870x2 look at something like the corsair HX620 Watt. That should be enough for a single one and is great PSU. - Do you really need 2x 4870x2's?

mojomonkeyx · 21 Aug 2008 at 14:45

I don't need 2 4870 X2's, but I'm looking to the future where in maybe a year or maybe 2 years I want a bit more power on the graphics front.

The way my cashflow works is that I'd be happier buying a cheaper PSU now that would comfortably run my single X2 and upgrading later if I need to, if there is a massive difference in pricing.

@EsaT: The power meter is on my Zalman MFC2, as I am writing this post to you I am apparantly on 135W.

@EsaT comment #2: I know that the X2 is a dual GPU solution (2 4870's in CF essentially, with a PCI express bridge), but it still seems to use a great deal of juice!

Pilky01 · 21 Aug 2008 at 14:46

mojomonkeyx said:
I don't need 2 4870 X2's, but I'm looking to the future where in maybe a year or maybe 2 years I want a bit more power on the graphics front.

The way my cashflow works is that I'd be happier buying a cheaper PSU now that would comfortably run my single X2 and upgrading later if I need to, if there is a massive difference in pricing.

@EsaT: The power meter is on my Zalman MFC2, as I am writing this post to you I am apparantly on 135W.

@EsaT comment #2: I know that the X2 is a dual GPU solution (2 4870's in CF essentially, with a PCI express bridge), but it still seems to use a great deal of juice!

A crosiar hx620 can run a single x2. They cost £88.

sibeer · 21 Aug 2008 at 16:48

I'm sure that if your current 600W PSU is a branded one (eg Seasonic, Antec, Coolermaster, etc) then it will be fine for your first 4870X2. When you come to get a second you can be sure that the more powerful PSU's will be cheaper so buy then. Clearly if your system is currently using 135W (sounds right to me), then add another 200W peak device still leaves lots of clearance from 600W. I am sure that a couple of molex to PCI-E converters will be a much cheaper option.