GeForce GTX 260 vs Radeon HD 4890 2GB

Intro

Compare those specifications to the Radeon HD 4890 2GB, which makes use of a 55 nm design. ATi has set the core speed at 1000 MHz. The GDDR5 memory is set to run at a frequency of 975 MHz on this specific card. It features 800(160x5) SPUs along with 40 TAUs and 16 Rasterization Operator Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 260		182 Watts
Radeon HD 4890 2GB		190 Watts
	Difference: 8 Watts (4%)

Memory Bandwidth

In theory, the Radeon HD 4890 2GB will be 12% quicker than the GeForce GTX 260 in general, due to its greater data rate. (explain)

Radeon HD 4890 2GB		124800 MB/sec
GeForce GTX 260		111888 MB/sec
	Difference: 12912 (12%)

Texel Rate

The Radeon HD 4890 2GB should be just a bit (approximately 9%) faster with regards to AF than the GeForce GTX 260. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
GeForce GTX 260		36864 Mtexels/sec
	Difference: 3136 (9%)

Pixel Rate

The GeForce GTX 260 is just a bit (approximately 1%) better at FSAA than the Radeon HD 4890 2GB, and should be capable of handling higher resolutions without losing too much performance. (explain)

GeForce GTX 260		16128 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 128 (1%)

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 data (in units of MB per second) that can be transferred across the external memory interface within a second. It's calculated by multiplying the bus width by its memory speed. If the card has DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This figure is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, the better the card will be at handling 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 could possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.