Is this even possible?

[MeanUncleBob]

A neighbor in my building claims to be running a AMD quad core processor and a geforce 9800 gx2 powered by a 300 watt power supply. Do you think that he is BSing, mistaken or could this power supply just be giving more juice than it's supposed to? He does say the system is very hot. To me that indicates a slight possibility that the power supply is supplying enough amps but is going to burn out soon.

He does say lots of strange things.

 

[djcoolmasterx]

He's either lying, doesnt know what PSU he has or is about to have a failure; either way he is an idiot.

 

[anthropophaginian]

It might be just about possible if you choose a low power phenom and use a single low power harddrive and any way to save power. However, you're going to put a lot of strain on the PSU, and it probably won't last long. So he's a moron or mistaken. Or lying.

 

[Onus]

Maybe he doesn't game (but why that card then?). The GX2 running 3D needs 217 watts. The lowest Phenom quad needs up to 95W. That's 313 right there. /TILT/
The prior assessments appear to be quite accurate.

 

[theAnimal]

Anandtech measured 346 at the wall with an i7 965 & 9800GX2. That's less than 300W at the PSU.

 

[Devastator_uk]

Disable 3 of the 4 cores, then under-clock as much as possible, and underclock graphics and don't have a harddrive (boot from usb or lan), no optical drive and 300W should be plenty

 

[pinaplex]

running that setup on a 300W psu might be possible but not at all smart. Just like Chris Rock said, "you can drive a car with your feet, but it doesn't mean it's to be done!"

think of running your cars engine at its redline all the time, that's similar to what he's doing....

 

[grieve]

I think as the others have mentioned that this is possible. I would be curious if the machine will crash under load.

I also agree with the others, either way your neighbor is an idiot...

 

[JohnnyLucky]

A single 9800GX2 uses 217.5 watts and 18.1 amps at load.

The source of the information is the Tom's Hardware article about video cards and power requirements. There is a link to the article on the home page.

A power supply such as the SeaSonic SS-300TFX 300W TFX12V 80 PLUS Certified Active PFC Power Supply is rated at 36 amps.

Hmmmm......it seems quite possible depending on the rest of the components and the configuration.

 

[MeanUncleBob]

A single 9800GX2 uses 217.5 watts and 18.1 amps at load.

The source of the information is the Tom's Hardware article about video cards and power requirements. There is a link to the article on the home page.

A power supply such as the SeaSonic SS-300TFX 300W TFX12V 80 PLUS Certified Active PFC Power Supply is rated at 36 amps.

Hmmmm......it seems quite possible depending on the rest of the components and the configuration.

http://archive.atomicmpc.com.au/forums.asp?s=2&c=7&t=9354 gives a more conservative usage of 182 watts, but that's still a big bite. I'm going to check out that article because my card (8800gt oc2) doesn't have a listing anywhere. Supposed to have a total of 28A on the 12V and my power supply only has 18A. Didn't even come up and say that it would be working in low power mode or anything like that (read about something like that......somewhere). Worked fine in another guy's system though. Thinking of doing the dual power supply thing until I can afford a good one from a real manufacturer. I'm pretty sure that my X2 5600 only uses 65W, (think it's a brisbane) but even if it's a windsor my video card would have to be drawing fairly close to the gx2 level to use up 18A. Or perhaps the power supply (OKIA from old system) is just cheap, old and tired--which would mean it's suited to me I guess.

 

[Nik_I]

i say the system would run. but running and running well aren't necessarily the same thing... for all you know, he might have just manged to get the system to turn on with that power supply and then got a new one because it obviously didn't work.

 

[cjl]

A single 9800GX2 uses 217.5 watts and 18.1 amps at load.

The source of the information is the Tom's Hardware article about video cards and power requirements. There is a link to the article on the home page.

A power supply such as the SeaSonic SS-300TFX 300W TFX12V 80 PLUS Certified Active PFC Power Supply is rated at 36 amps.

Hmmmm......it seems quite possible depending on the rest of the components and the configuration.

Are you sure about the 36 amp figure? 36 amps on the 12V rail is 432 watts on the 12V alone, so it seems somewhat implausible on a 300W PSU.

 

[MeanUncleBob]

Are you sure about the 36 amp figure? 36 amps on the 12V rail is 432 watts on the 12V alone, so it seems somewhat implausible on a 300W PSU.

I had to check that out. The two 12V rails combine to give 252W. I'll have to look through some more info before I can even come near to understanding.

 

[cjl]

I have no doubt that the listed config could work - a lot of people don't realize that components don't take as much power as they might think, and with a lower power Phenom, it would definitely be doable. What I'm doubtful of is that there's any 300W PSU with a 36A 12V rail.

Edit: looking at that PSU, it has 2 12V rails at 18A peak each, but it cannot exceed a total 12V load of 252W (21A combined max load). Basically, it's saying you don't need to carefully balance the 12V rails, but you can't draw anywhere near 36A from that 12V.

 

[JohnnyLucky]

The source of the information is the Tom's Hardware article about video cards and power requirements. There is a link to the article on the home page. The power and amperage charts are on page six of the article:

http://www.tomshardware.com/reviews/geforce-radeon-power,2122-6.html

I just checked to make sure I was looking at the results for the 9800 GX2 (2x512 MB). It's the third listing in the first chart.

Here's the Seasonic web page for the power supply:

http://www.seasonicusa.com/tfx.htm

It is showing two 12 volt rails at 18 amps each but nowhere does it state it has multiple rails. The psu's usually have one large 12 volt rail that is divided in "virtual rails". It appears to be an advertising gimmick. There have been numerous articles about the advertising hype. Seasonic also manufactures Corsair and PC Power & Cooling psu's. I know all of the Corsair units are one large 12 volt rail. I was just using the Seasonic psu as an example. It was the first 300 watt psu at newegg that I noticed.