power needed for 9800

[Rebel Son]

I have a 9800xt coming and I would like to know how much of a power supply I need. It needs 300 watts to run. how about 550-600, or is that to much?
thanks

3.2ht\512 cache
2x512 pc3200 kingston
9800xt
soundblaster audigy 2
gigabyte ga-8knxp
seagate 120gb

[embj]

It doesn't require 300 watts to run. I'm using a generic 350 watt PSU. I'm using a power hungry overclocked AMD system with a Radeon 9800 Pro that is overclocked past XT speeds. I'm not even using 300 watts of power I know because I'm using a 500 VA UPS that only supports a maximum of 300 watts of power going through it. If I was using 300 watts it would be beeping like crazy telling me that it is overloaded. You should be fine with a 400-450 watt PSU.

[FastHotRod]

I hear this a lot and there seems to be a misconception about what "power" really is. If you were to compare a power supply to a pickup truck, it would probably be easier for you to understand.

For example, if I have a Ford F-150 (150 watt power supply) and just use to to drive around town, I'm cool. Load it with a 1/2 ton of stuff and I'm still okay but pushing the design limits...

So I upgrade to a Ford F-350 (350 watt power supply) and I drive around... cool. Load it with 1/2 ton of of stuff... still cool because it was designed to handle more load that I am currently using. So now I slam it full with a ton of dirt... still okay, but pushing the limits again...

So I buy a Ford F-450 dump truck... Get the point?

The same applies to computer power supplies. Just because you can supply 350/400/500 watts doesn't mean that you will always use the capacity. You could, but you won't necessarily (all based on what parts are in your computer.) Feel free to use that higher rated power supply... if it's a quality unit that can actually perform based on it's specifications.

Also, remember that you could probably put a couple ton of dirt in a 1/2 ton truck... but it probably won't last very long.

Hope this helps.

Mark

Originally posted by Rebel Son
I have a 9800xt coming and I would like to know how much of a power supply I need. It needs 300 watts to run. how about 550-600, or is that to much?
thanks

3.2ht\512 cache
2x512 pc3200 kingston
9800xt
soundblaster audigy 2
gigabyte ga-8knxp
seagate 120gb

[FastHotRod]

Again, another misconception. (Don't mean to flame you, sorry.) Your 350 watt PSU is rated at the outputs of it, I.E current output on the +12v rail, -12v rail, +5v rail, -5v rail, etc.... those voltages are all DC (direct current) and total power can be calculated by multiplying the voltage by the current.

For example, a 200 watt PSU may have these specs: (+12v rail @ 10 amps is 120 watts. +5v rail @ 20 amps is 100 watts, -12v rail @ 0.5 amps is 6 watts, etc....) A 200 watt PSU might only pull about 1 amp from the 120 VAC outlet. (120 actual watts) It's really dependent on the design of the PSU and the quality of the components used during manufacture.

Thing is, a PSU converts AC power to DC power. There is a transformer that changes the 120 volts to a lower AC voltage level, then is rectified to DC and filtered to attempt to make the best DC it can. The conversion rate is not normally 1:1 in those cases. (I could get into specifics, but this post would be pages long...)

A 500 VA UPS is rated differently than a PSU. A 500VA UPS is designed to provide 500 VA (volt/amperes) to a load. That could be a light bulb, computer, etc... It actually takes AC, converts it to DC, then back to AC again. Depending on the power factor, your 500 VA UPS should be able to put out 500 watts of AC power, more than enough to power two or three 350 watt PSU's. If your UPS is overload beeping at 300 watts, you need a replacement.

Understand that this is all a "guess-timation" on my part because I don't have your component specifics in front of me. Shoot me some specifics and I can give you better calculations. Hope this helps.

Mark

p.s. Sorry if I sounded like I flamed you, that was not my intention.

Originally posted by embj
It doesn't require 300 watts to run. I'm using a generic 350 watt PSU. I'm using a power hungry overclocked AMD system with a Radeon 9800 Pro that is overclocked past XT speeds. I'm not even using 300 watts of power I know because I'm using a 500 VA UPS that only supports a maximum of 300 watts of power going through it. If I was using 300 watts it would be beeping like crazy telling me that it is overloaded. You should be fine with a 400-450 watt PSU.

[Tazzin]

My suggestion is .. try it with the power supply you have now! I am sure that it will work fine. If it goes bad.. then go buy a new one. What would you do with the old power supply? It will sit in your closet or somewhere collecting dust .. like mine

I am running an AMD 2400+ on a Gigabyte GA-7N400 Pro MOBO with 2x512 DDR PC3200 RAM .. ATI 9800 Pro ... 160GB WD 7200 RPM HD... DVD ROM and CD-RW ... it stays on 24/7 .. no problems yet with the stock case power supply... 350 Watt.

[Sweeper]

what are the specs on your PSU? Your 12v, +5v, +3.3v ?