1600x900 to 1920x1080

No, it doesn't work that way. You have a monitor with 1600 pixels across, with 900 pixel down in a grid. You can't turn it into any other res. You can emulate lower resolutions like 1440x800, but you can't make pixels appear out of no where.

if you want to create more stress on the GPu, try increasing the AA from the in-game settings.
or try forcing AA through the driver control options.
on all cards, forcing FSAA will put a lot of stress on the gpu, sometimes halving the FPS,

it works when im not in a game but things get small thats why i think it would be possible.

?

i can put the resolution up to full hd but things get small.

Why do you want to put more stress on the gpu?

Which monitor are using anyways?
You can't set the resolution up from your native resolution. Either the screen won't fit or it would appear small.
And as mayankleboy said, you can try turning on AA in games if you want to put some stress to your video card.

i want to put more stress on the gpu so it would be fair in benchmarks and easy to compare to other systems.

6850 im getting a 2nd 1 soon

Yeah, for 1600X900, it's a good card. But for 1080p, I'd get a Radeon HD 6950 or a GTX 560 Ti. The former is less expensive though.

Best answer selected by 9_breaker.

This topic has been closed by Mousemonkey