GeForce GTX 870M vs Radeon HD 4890 1GB

Intro

Compare those specs to the Radeon HD 4890 1GB, which uses a 55 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 memory runs at a frequency of 975 MHz on this particular card. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 870M		110 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 80 Watts (73%)

Memory Bandwidth

Performance-wise, the Radeon HD 4890 1GB should in theory be much better than the GeForce GTX 870M overall. (explain)

Radeon HD 4890 1GB		124800 MB/sec
GeForce GTX 870M		96000 MB/sec
	Difference: 28800 (30%)

Texel Rate

The GeForce GTX 870M will be quite a bit (approximately 163%) faster with regards to anisotropic filtering than the Radeon HD 4890 1GB. (explain)

GeForce GTX 870M		105392 Mtexels/sec
Radeon HD 4890 1GB		40000 Mtexels/sec
	Difference: 65392 (163%)

Pixel Rate

If running with a high screen resolution is important to you, then the GeForce GTX 870M is the winner, and very much so. (explain)

GeForce GTX 870M		22584 Mpixels/sec
Radeon HD 4890 1GB		16000 Mpixels/sec
	Difference: 6584 (41%)

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 largest amount of information (counted in MB per second) that can be transferred past the external memory interface in a second. The number is calculated by multiplying the bus width by its memory speed. If the card has DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total amount of texture units of the card 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 per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the video card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.