GeForce GTX 970 vs Radeon HD 4850 X2 1GB

Intro

Compare that to the Radeon HD 4850 X2 1GB, which has a GPU core clock speed of 625 MHz, and 1024 MB of GDDR3 memory set to run at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 970		145 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 105 Watts (72%)

Memory Bandwidth

Performance-wise, the GeForce GTX 970 should theoretically be quite a bit superior to the Radeon HD 4850 X2 1GB overall. (explain)

GeForce GTX 970		224000 MB/sec
Radeon HD 4850 X2 1GB		127104 MB/sec
	Difference: 96896 (76%)

Texel Rate

The GeForce GTX 970 is a lot (approximately 118%) more effective at texture filtering than the Radeon HD 4850 X2 1GB. (explain)

GeForce GTX 970		109200 Mtexels/sec
Radeon HD 4850 X2 1GB		50000 Mtexels/sec
	Difference: 59200 (118%)

Pixel Rate

The GeForce GTX 970 should be quite a bit (about 236%) more effective at FSAA than the Radeon HD 4850 X2 1GB, and will be able to handle higher resolutions while still performing well. (explain)

GeForce GTX 970		67200 Mpixels/sec
Radeon HD 4850 X2 1GB		20000 Mpixels/sec
	Difference: 47200 (236%)

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 maximum amount of information (in units of megabytes per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the bus width by the speed of its memory. If the card has DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the video 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 number of pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel 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 get to the max fill rate.