GeForce 8600 GT 512MB DDR2 vs GeForce GT 420

Intro

Compare those specifications to the GeForce GT 420, which has core clock speeds of 700 MHz on the GPU, and 900 MHz on the 2048 MB of GDDR3 memory. It features 48 SPUs as well as 8 TAUs and 4 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8600 GT 512MB DDR2		47 Watts
GeForce GT 420		50 Watts
	Difference: 3 Watts (6%)

Memory Bandwidth

In theory, the GeForce GT 420 should be a lot faster than the GeForce 8600 GT 512MB DDR2 in general. (explain)

GeForce GT 420		28800 MB/sec
GeForce 8600 GT 512MB DDR2		12800 MB/sec
	Difference: 16000 (125%)

Texel Rate

The GeForce 8600 GT 512MB DDR2 should be quite a bit (about 54%) better at anisotropic filtering than the GeForce GT 420. (explain)

GeForce 8600 GT 512MB DDR2		8640 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 3040 (54%)

Pixel Rate

If running with high levels of AA is important to you, then the GeForce 8600 GT 512MB DDR2 is superior to the GeForce GT 420, by a large margin. (explain)

GeForce 8600 GT 512MB DDR2		4320 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 1520 (54%)

Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.

Price Comparison

Specifications

Memory Bandwidth: Bandwidth is the maximum amount of data (in units of MB per second) that can be transferred over the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.