View Full Version : 7800 gtx 512mb power supply

02-24-06, 01:40 PM

I dont understand why BF2 runs so jumpy and with not particualry impressive fps... From like 70fps down to 50 fps and i see 40 fps too.
1280x1024, x4aa + x8af

I've tried loads of nvidia drivers... [I have a 2mb bt yahoo adsl connection]

That may look alright, but the actual gameplay just isnt smooth, feels jumpy and chuggy.

I think a possible weakness could be my power supply?

http://cgi.ebay.com/Dell-NEW-NPS-460BB-C-Dell-Xps-gen-3-power-supply_W0QQitemZ6849342555QQcategoryZ42021QQcmdZVi ewItem#ebayphotohosting

Its a Dell 460W PSU

two 12V rails rated at 18.5 amps? [from wot i can see]

02-24-06, 01:41 PM
I just had a look at the box for my graphics card and it says it requires:


450W PSU with (12 V rail of 26A)

So does my psu only have 18.5A on the 12V rail? or is it two 18.5A combined?
Hence, i need a psu with the 12 V rails rated @ 26A each????

02-24-06, 05:33 PM
If you read the label on the ebay listing carefully, you'll see that the supply has a maximum current of 18.5A on *each* of the two +12V rails. The sum of the currents on those rails is limited to less than 34A.

There must be additional limits as well. If that 34A was available, and the +3.3V and +5V lines were run to the maximum rated sum of 240W, the supply would be delivering 648W. That would be nice, but it seems a bit much to expect.

That seems like it ought to be more than adequate. However, see the second page of:


The system built for that test used an A64 FX60 CPU and a pair of 512 MB 7800GTX cards, and a Silverstone 600W supply wasn't adequate. If it's this one:


note that it has *4* rails, 13A + 18A + 16A + 8A (that's a nominal 55A total). The one that ran without trouble was:


(PC Power & Cooling 850W, 16A +16 A + 30A, < 54A sum).

That's a bit scary.

I've run a 4400+ (overclocked to 2.42 GHz) with a single 256 MB 7800 GTX quite stably with a Tagan 480W supply that provides 28A max on its single +12V rail.

I'd bet that your PSU is adequate, but I wouldnt bet more than 5 cents.

02-24-06, 09:35 PM
I would think your power supply would be fine since it put out 18amps on 2 12v rails giving you arounf 37 amps,but you never know unless you try a different power supply

02-26-06, 05:39 AM
But you cannot just add the two rails together, can you?

02-26-06, 12:25 PM
dont think so

02-26-06, 01:17 PM
your psu is fine its just the game has poor coding.... go to my documents and delete all folders under battlefield2->mods->bf2... this will force the game to create a new shader cache... no chugging on my system and i play at 1280x960 4xAA/high texture filter (4xAF)... u can try setting pb to refresh less.... join a game and open console and type pb_sleep 500 and then pb_writecfg... also turn off any firewall/av