GeForce GTX 465 vs Radeon HD 4890 2GB

Intro

Compare that to the Radeon HD 4890 2GB, which comes with a clock speed of 1000 MHz and a GDDR5 memory frequency of 975 MHz. It also features a 256-bit bus, and uses a 55 nm design. It is made up of 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4890 2GB		190 Watts
GeForce GTX 465		200 Watts
	Difference: 10 Watts (5%)

Memory Bandwidth

The Radeon HD 4890 2GB should in theory be a lot faster than the GeForce GTX 465 overall. (explain)

Radeon HD 4890 2GB		124800 MB/sec
GeForce GTX 465		102592 MB/sec
	Difference: 22208 (22%)

Texel Rate

The Radeon HD 4890 2GB will be a lot (more or less 50%) faster with regards to AF than the GeForce GTX 465. (explain)

Radeon HD 4890 2GB		40000 Mtexels/sec
GeForce GTX 465		26708 Mtexels/sec
	Difference: 13292 (50%)

Pixel Rate

The GeForce GTX 465 should be much (about 21%) faster with regards to full screen anti-aliasing than the Radeon HD 4890 2GB, and also will be able to handle higher screen resolutions without slowing down too much. (explain)

GeForce GTX 465		19424 Mpixels/sec
Radeon HD 4890 2GB		16000 Mpixels/sec
	Difference: 3424 (21%)

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

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

Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the core 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 fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.