Power Supply Question

d3moliti0n · 2 Feb 2009 at 21:27

Hi

I'm thinking about upgrading my graphics card on my computer, but what is the lowest wattage power supply I would need to run my system (see signature) and a 4850/4870?

Thanks for your help.

ChrisLX200 · 2 Feb 2009 at 21:31

About 500w, probably work with less but why struggle with the minimum if you're in the market to buy a new PSU? What d you have right now?

Kennysevenfold · 2 Feb 2009 at 21:32

your better getting a higher powerred psu than you need, they run more efficiand that a psu that is oan load constantly, plus, you your system only needs 300watts and you have a 800 watt psu, you will still only use 300watts, so it leaves room for the future

and wont have such a strain on the psu which will in turn last longer and run cooler

something like this, cant really go wrong..

http://www.overclockers.co.uk/showproduct.php?prodid=CA-008-CS&groupid=701&catid=123&subcat=1084

d3moliti0n · 2 Feb 2009 at 21:34

A crappy PSU, it says it's 650w but the amps on the 12v are crap so it's only like 300w or something in reality.

ChrisLX200 · 2 Feb 2009 at 21:38

If it's that **** then it's a good plan to upgrade it anyway. the high performance GFX card (and the rest) likes smooth, clean power so get yourself a decent PSU - worry less about watts and more about build quality. A good 500 would do, no harm going a bit higher output if you have the money. Don't sacrifice quality for output.

Kennysevenfold · 2 Feb 2009 at 21:40

d3moliti0n said:
A crappy PSU, it says it's 650w but the amps on the 12v are crap so it's only like 300w or something in reality.

so what amps are on its 12v rail then.?

icey_haj · 2 Feb 2009 at 21:41

ChrisLX200 said:
If it's that **** then it's a good plan to upgrade it anyway. the high performance GFX card (and the rest) likes smooth, clean power so get yourself a decent PSU - worry less about watts and more about build quality. A good 500 would do, no harm going a bit higher output if you have the money. Don't sacrifice quality for output.

Agreed. I would also add another 2GB of RAM, they're cheap as chips these days.

d3moliti0n · 2 Feb 2009 at 21:45

Is this power supply any good? http://www.overclockers.co.uk/showproduct.php?prodid=CA-026-OC&groupid=701&catid=123&subcat=

icey_haj · 2 Feb 2009 at 22:00

Coolermaster 520W
Zalman 500W
Corsair 520W (Out of Stock)

I would personally choose out of these 3

d3moliti0n · 2 Feb 2009 at 22:16

So, the OCZ one is no good then?

icey_haj · 2 Feb 2009 at 22:47

d3moliti0n said:
So, the OCZ one is no good then?

I would rather not go for it tbh

S.A.S · 3 Feb 2009 at 00:35

The zalmans are fantastic, the guys on the forum told me to go with one and it worked perfect in a 4850x2 build.

the zalman 650 would be a good future proof PSU

simbady · 3 Feb 2009 at 01:13

Corsairs are also great really quite.

Lumeycom · 3 Feb 2009 at 10:35

Kennysevenfold said:
your better getting a higher powerred psu than you need, they run more efficiand that a psu that is oan load constantly.......(SNIP)

People keep saying this and there is no logic that I can see behind it. an 80% efficient 500w psu will use the same amount of power at 300w that a 1000w 80% efficient psu.

Power is power, affected only by power factor (or effiiciency in friendly terms)...

Unless years of electrical training decieves me ofc, or theres leprechauns involved.

EsaT · 3 Feb 2009 at 10:53

Good 250W PSU would be enough for your current config but no such available so would have to be satisfied with around 350W PSUs.

With 4870 peak draw would reach to mighty 220-230W.
Corsair VX450 is good for nearly any single GPU PC.

S.A.S said:
The zalmans are fantastic, the guys on the forum told me to go with one and it worked perfect in a 4850x2 build.

Even crap PSU would power 95% of gaming PCs because PCs don't consume as much as loudest yellers think.
Besides I haven't yet seen innards shot of Zalman which would include highest quality capacitors.

Lumeycom said:
an 80% efficient 500w psu will use the same amount of power at 300w that a 1000w 80% efficient psu.

Power is power, affected only by power factor (or effiiciency in friendly terms)...

Efficiency isn't flat line but curve with drop especially in low load end so assuming similar designs that 1kW nuclear power plant would waste more power because with 500W PSU load would hit directly to range of highest efficiency. And especially during 90% time when PC is on (idling, web surfing) efficiency of later would be crappy.

And power factor doesn't have anything to with with efficiency or consumed power, just only with how much there's reactive power increasing apparent power.

d3moliti0n · 3 Feb 2009 at 11:08

Is this power supply any good? http://www.antec.com/uk/productDetails.php?ProdID=05506

I am thinking of buying either a 9800GTX or a 4850, and am going to upgrade to 4GB or memory and maybe a quad-core CPU in the near-future. Will this PSU be able to run all of those things?

S.A.S · 3 Feb 2009 at 11:22

yes the antec neopower 500w is ok

Nullvoid · 3 Feb 2009 at 11:31

EsaT said:
Even crap PSU would power 95% of gaming PCs because PCs don't consume as much as loudest yellers think.
Besides I haven't yet seen innards shot of Zalman which would include highest quality capacitors.

The 1000w/850w are Enhance designs: http://www.silentpcreview.com/article834-page3.html

The 750w/600w/500w are based on the FSP Epsilon but instead of just getting them rebadged they got FSP to tweak the design enough to solve the ripple problems: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story2&reid=30