I have low power computer:

Pentium 4
Motherboard: Asus P5GPL-X
Processor: Intel Pentium 4 506, 2676 MHz (20 x 134)
Video card: Nvidia GEforce 6200 TC (256Mb)
Ram: 1024 + 256 = 1280Mb DDR 1
PSU: 350 Watts

Test Drive Unlimited
I really want to know: maybee there is some way how to change graphics few times lower than Minimum.
Becouse at Minimum graphics and 640 x 480 resolution Test Drive Unlimited is glitching on my comp!

And for further:
How much Watt PSU i need to Nvidia GeForce 7900 (PCI-EX) work properly?
Sparkle GeFORCE 7900GS Cool pipe, PCI-E, 256MB DDR3, 256Bit, Core Clock 450MHZ, Memory Clock 1320MHz, HDTV-OUT, DUAL DVI

I'll be glad for any help.
Thank you

There may be a way to make TDU run in DirectX 7 mode which would vastly improve your FPS but sacrifice shader effects.

And I would estimate a 400W PSU.

i used to have a 850XT running with 350w........ lol even worked with my new 8800 gts, but switched to a 420w

So, i can for begining use Nvidia GeForce 7900GS on 350 Watts PSU?
Then i'll change Psu to 420W...

Can do that?

7900GS Video Card will work on 350 Watt's PSU?

It depends what quality the PSU is.

If its a good brand like Thermaltake, Antec, Enermax, Asaka, OCZ then you should be ok.

If its a cheap no-name brand then it probably won't be enough - I've had faaar too much trouble with cheap PSUs to even try and run a no-name one - I'd buy a better one straight away.

Ok, thank you for info.
And on thing: I buy new PSU, i put it in the computer and and set in to motherboard all wires. No installing is needed?

Well yes, you put PSU in computer, connect all wires (motherboard,videocard etc.).

it should run without a new PSU, even if it is a poor one; the step from 6200 to 7900GS is probably less than 40Watts, and your system isn't that power hungry.. Should be fine!

However, don't expect TDU to run great; its not the most optimized game and tends to chug at times, even on far more faster hardware than you have!

[off-topic]LMAO at your avatar, Neils. What did they do to you to make them buy rFactor? I'd never do that to my worst enemy [/off-topic]

[off topic still] Well the number is probably at about 6! Its that car I did the physics for that drove a couple of LFSers towards rFactor, for a short flirt I suppose.