GeForce GTX 275 vs Radeon HD 4850 X2 1GB

Intro

Compare that to the Radeon HD 4850 X2 1GB, which has a clock speed of 625 MHz and a GDDR3 memory speed of 993 MHz. It also features a 256-bit memory bus, and makes use of a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 275		219 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 31 Watts (14%)

Memory Bandwidth

Theoretically, the Radeon HD 4850 X2 1GB should be just a bit faster than the GeForce GTX 275 overall. (explain)

Radeon HD 4850 X2 1GB		127104 MB/sec
GeForce GTX 275		127008 MB/sec
	Difference: 96 (0%)

Texel Rate

The GeForce GTX 275 is a little bit (approximately 1%) faster with regards to AF than the Radeon HD 4850 X2 1GB. (explain)

GeForce GTX 275		50640 Mtexels/sec
Radeon HD 4850 X2 1GB		50000 Mtexels/sec
	Difference: 640 (1%)

Pixel Rate

The Radeon HD 4850 X2 1GB is just a bit (about 13%) faster with regards to FSAA than the GeForce GTX 275, and also should be capable of handling higher screen resolutions more effectively. (explain)

Radeon HD 4850 X2 1GB		20000 Mpixels/sec
GeForce GTX 275		17724 Mpixels/sec
	Difference: 2276 (13%)

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.

One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the largest amount of information (counted in MB per second) that can be transferred past the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.