GeForce GTX 970M vs Radeon HD 4870 2GB

Intro

Compare all that to the Radeon HD 4870 2GB, which comes with a core clock speed of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also makes use of a 256-bit bus, and makes use of a 55 nm design. It is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 970M		75 Watts
Radeon HD 4870 2GB		150 Watts
	Difference: 75 Watts (100%)

Memory Bandwidth

In theory, the Radeon HD 4870 2GB will be 20% quicker than the GeForce GTX 970M overall, due to its greater bandwidth. (explain)

Radeon HD 4870 2GB		115200 MB/sec
GeForce GTX 970M		96000 MB/sec
	Difference: 19200 (20%)

Texel Rate

The GeForce GTX 970M is a lot (about 146%) faster with regards to AF than the Radeon HD 4870 2GB. (explain)

GeForce GTX 970M		73920 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 43920 (146%)

Pixel Rate

The GeForce GTX 970M should be a lot (about 270%) better at AA than the Radeon HD 4870 2GB, and will be capable of handling higher screen resolutions without slowing down too much. (explain)

GeForce GTX 970M		44352 Mpixels/sec
Radeon HD 4870 2GB		12000 Mpixels/sec
	Difference: 32352 (270%)

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: Memory bandwidth is the maximum amount of data (measured in MB per second) that can be transferred past the external memory interface in a second. The number is worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

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

Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.