Power Supply for the 4850/4770

[mribrahimali]

hi, i have been considering buying either a 4850, or a 4770, however, i was researching the requirements and Ati, say " 450 Watt or greater power supply with 75 Watt 6-pin PCI Express® power connector recommended" for both cards.

atm, i have a 300 watt power supply unit,would the cards run on this or would i have to buy a new power supply?

if the cards would not run, could you recommend a suitable card that would run on the following specs:

Intel® Pentium® D 935 (Dual Core) 64-bit 3.2 ghz
2048 MB DDR2, 667 MHz, (PC2-5300) dual channel memory
300 watt power supply
# One PCI Express ×16 (graphics interface)
# One PCI Express ×1
# Two PCI conventional

if i have missed anything out, should be here : support.gateway.com/s/PC/R/1014800R/1014800Rsp2.shtml

thanks

[stevie lee]

to help out other people who may want to help, heres some links in relation to the above post. - i'm not sure whether those cards mentioned, or even the Radeon 4650/4670 will work without buying a new power supply.

http://www.support.gateway.com/s/PC/...4800Rsp2.shtml

the 300w PSU is either http://support.gateway.com/s/POWER/6...6088Rsp2.shtml OR http://support.gateway.com/s/POWER/6...6092Rsp2.shtml

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welcome to HEXUS aswell.. they're usually a friendly knowledgeable buch around here.

[mribrahimali]

Alright then, thanks a lot for the quick reply

new PSU it is then

[stevie lee]

remember not to go overboard on the PSU, a decent 450W will suffice for your system. enermax, FSP, seasonic, Corsair, are all recommended by various people around here.

just have a quick look at my 'my system' on the left. i run a 1gb 4870, 8 gb ram, 5 hard drives dvd, seperate sound card all on a 425W enermax.

edit:

i did say i wasnt sure whether it would work or not, i would wait for some more people to post before upgrading.

[mribrahimali]

ok, will do

[sammorris]

A 300W of top notch quality would do it, as a 130W Pentium D with an HD4770 would be a total system draw of about 230-240W or so full load. However, that's cutting it a bit fine, especially with a gateway unit. I'd recommend something like a 400W Corsair CX.

[mribrahimali]

OK, so it needs a new PSU, and this will probably sound stupid, but will the more powerful supply damage the other components?, and would there be any real issue with dimensions of the PSU, or is it pretty much standardised?

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thanks a lot for all your replies by the way

[sammorris]

No, as long as you don't buy a bad brand, it doesn't matter what the wattage is, you can't damage the system with a high output PSU, PSUs only produce what the PC needs, the figure they're rated for is the MAXIMUM. As long as you have a standard ATX case and not, say an unusual Gateway or Dell system, any ATX PSU will fit, as long as there's room for it (some smaller cases have the PSUs very close to, for example, the cd drives, so you have to make sure to get short ones. This isn't often a problem though)

[Swiftes]

A Corsair CX400 would be nice for that, overkill but very much capable of powering such a setup and doing a marvellous job of it too.

[Zak33]

A power supply only SUPPLIES.. it doesn't FORCE power.

So you COULD in THEORY have a 1000 W power supply and your PC would still only TAKE what it wanted, so you're quite safe with a higher rating.

The reason ATI has to be cautious wth power ratings is that many many power supplies are over described, and it's very much like stereo's.

A £40 stereo that CLAIMS to be able to supply 2x50W probably can... for about 1/1000 th of a second, and in doing so will sound aweful The rest of it's working life it'll be nothing of the sort.
A GOOD amp that claims to be 2x20W can do 20watts it's entire life, all the time.
And the bad amp will potentially damamge your speakers with it's uncotrolled power.

A good and bad Power Supply are very similar. A Cheap branded one that states 600w might only be able to manage 600w for a few short seconds and then falter... and in doing so MIGHT blow up your components. A Well made, quality unit, will be stable consistent and more than capable.
A really good brand psu (power supply unit) could be a much lower rating and maintain it's stated power all day long.

ATI has to over egg the pudding... it must over state it's requirements so that you don't shout "unfair" when a crappy 400w unit fails to run your new card, where someone else's 400w unit does it easily.

Hope that makes sense. In essense.. a cheap power supply is a bad bad idea

[sammorris]

Agreed. For instance, I'm drawing 700W ish with my 4870X4 setup, and AMD say you should really have a 1KW PSU minimum for it. My 850W unit handles it fine, but a lot of other 850W units would go bang and possibly destroy the system, because they aren't truly 850W. At this top end scale, even BeQuiet and Enermax units routinely fail this. Zalman, Corsair and PCP&C seem to be the only trustworthy units up this high.

[mribrahimali]

I understand now, thanks.

[Zef]

I bought the 4850 and it ran fine with my basic 300W PSU although I wouldn't recommend it because it was probably at the limit of it's capability. Also make sure your PSU has the right connectors for the card. If not, it definitely won't work. I bought a 550W Corsair and I'm very pleased with it:

-It's got more power than you need
-More connectors than you need
-It's very quiet
-With the old PSU I would hear a high pitched buzz through the headphones when more power was being used. The new one has eliminated that (lower electrical noise from higher quality components I think?)

So if you get a quality PSU that's better than you need now, it will be able to handle future upgrades and avoid any annoyances that cheapo ones can give you.

[sammorris]

yeah, cheap PSUs are known for noise on the rails at high load, that probably caused it (even OCZ units are pretty bad for this). For ref, a PC with an HD4850 and a 65W dual core processor will use around 160-170W DC under load.

[nibbler]

I got a EZcool 450W never let me down
not even overly loud

[sammorris]

...yet. Seriously, a 450W EZCool (i.e. a 150W PSU with no overload protection) is dangerous for running anything but basic hardware.