MadShrimps have published NVIDIA Low Budget 7300 GT vs 8500 GT Comparison:

The Zotac 7300 GT DDR3 has only 128Mb onboard memory compared to the 256Mb on both 7300 GT DDR2 and 8500 GT models, but that doesn't seem to matter. You see, before you hit the memory bottleneck where memory size above 128Mb pays off you hit the limitation of the GPU. The only reason you see lower end cards with massive amounts of onboard memory is marketing.

In our tests we saw 7300 GT with 256Mb DDR2 and GPU overclocked to 510Mhz, trail the 7300 GT with 128Mb DDR3 at stock speeds (GPU = 500Mhz). When we increased resolution which required more onboard memory, the GPU was unable to process the data quickly enough and performance dropped below playable levels, making the extra 128Mb on the 7300 GT DDR2 useless.

The 8500 GT from PNY is also equipped with 256Mb DDR2 and at stock speeds it had a hard time keeping up with the Zotac 7300 GT DDR3 card. If you don't intend to overclock, the older generation 7300 GT card will make a better deal, if you get the DDR3 powered version. Available in stores at <$70 it's cheaper and faster than the new 8500 GT video card.

If you are not afraid to play around with Rivatuner to extract the maximum performance from your video card, you will like the overclocking potential of the 8500 GT; In newer games which rely heavily on shaders for GFX effects the overclocked Shader engine on the card makes it shine, easily outperforming the older 7300 GT cards. But don't fool yourself, the card is still a low end budget card, overclocking will give you a bit of headroom but don't expect to play the latest games at high resolution and detail.

In low-budget related news, InsideHW.com takes a look at Intel Pentium E2140/2160 and C2D 6320/6420. It's very interesting to see what sub-100USD processors can do when overclocked against twice as expensive processors.