There is only some slightly fps difference affected by the shader clock only. I think Mad Shrimps had a benchmark review on more than 10 8800gts which can help you to clarified your doubt.
Mad Shrimps 8800gts 320mb Review

If you on a 22 incher, the 320mb should be ok enough but not too sure on a 24 incher. My 640mb still can handle most current games at 1920x1200 with max settings, 16x af and 2x or 4x aa. There only a few games which had lag with the settings such as in oblivion at wild with heavy grass scene, supcom where there are 100 over units bombarding a base.

This post has been edited by sniperwolf: Jun 19 2007, 03:51 PM

My pny 8800gts 640mb had the default fan speed set at 100% and I can say my aircond sound is more noticeable than the graphic card fan spinning sound.

How to determine whether its a split or not? As normal the fan compressor part is outside the room where as the 1 in the room is the blower la. Its not a too old model and if I not mistaken its the 1st panasonic model with ionizer which I bought around year 2004

Quite standard temp. My 640mb usually idle at max 65c (600/1900), where no fan nor air cond in a closed room with a dusty case chasis There already a thick layer of dust infront of the front intake fan part of my centurion 530 and still lazy to clean it . Probally will move all things out this weekend to move into the v1100 plus.

But the power consumed and heat generated is more than a 8800gts ler. If cant afford ultra, then just grab a GTX and oc it close to ultra lor

640mb would be better imo. As later if you might tend to upgrade to maybe a 24 to 28inch range monitor which utilize 1920x1200 resolution, the 640mb will still be a better performer over the 320mb