GeForce 8500 GT vs GeForce GT 420

Intro

Compare those specs to the GeForce GT 420, which features a core clock speed of 700 MHz and a GDDR3 memory speed of 900 MHz. It also makes use of a 128-bit bus, and uses a 40 nm design. It is made up of 48 SPUs, 8 Texture Address Units, and 4 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8500 GT		45 Watts
GeForce GT 420		50 Watts
	Difference: 5 Watts (11%)

Memory Bandwidth

As far as performance goes, the GeForce GT 420 should theoretically be much superior to the GeForce 8500 GT overall. (explain)

GeForce GT 420		28800 MB/sec
GeForce 8500 GT		12800 MB/sec
	Difference: 16000 (125%)

Texel Rate

The GeForce GT 420 is a lot (about 56%) better at AF than the GeForce 8500 GT. (explain)

GeForce GT 420		5600 Mtexels/sec
GeForce 8500 GT		3600 Mtexels/sec
	Difference: 2000 (56%)

Pixel Rate

The GeForce GT 420 will be quite a bit (approximately 56%) better at AA than the GeForce 8500 GT, and also capable of handling higher resolutions better. (explain)

GeForce GT 420		2800 Mpixels/sec
GeForce 8500 GT		1800 Mpixels/sec
	Difference: 1000 (56%)

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 max amount of information (in units of megabytes per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the bus width by the speed of its memory. If the card has DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to the local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.