Radeon HD 4870 2GB vs Radeon HD 4870 X2

Intro

Compare those specs to the Radeon HD 4870 X2, which features GPU clock speed of 750 MHz, and 1024 MB of GDDR5 RAM running at 900 MHz through a 256-bit bus. It also is comprised of 800(160x5) Stream Processors, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 2GB		150 Watts
Radeon HD 4870 X2		350 Watts
	Difference: 200 Watts (133%)

Memory Bandwidth

Performance-wise, the Radeon HD 4870 X2 should in theory be much superior to the Radeon HD 4870 2GB overall. (explain)

Radeon HD 4870 X2		230400 MB/sec
Radeon HD 4870 2GB		115200 MB/sec
	Difference: 115200 (100%)

Texel Rate

The Radeon HD 4870 X2 should be quite a bit (more or less 100%) more effective at anisotropic filtering than the Radeon HD 4870 2GB. (explain)

Radeon HD 4870 X2		60000 Mtexels/sec
Radeon HD 4870 2GB		30000 Mtexels/sec
	Difference: 30000 (100%)

Pixel Rate

The Radeon HD 4870 X2 is quite a bit (more or less 100%) more effective at anti-aliasing than the Radeon HD 4870 2GB, and will be capable of handling higher resolutions better. (explain)

Radeon HD 4870 X2		24000 Mpixels/sec
Radeon HD 4870 2GB		12000 Mpixels/sec
	Difference: 12000 (100%)

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: Bandwidth is the max amount of data (measured in MB per second) that can be moved across the external memory interface within a second. It's worked out by multiplying the bus width by the speed of its memory. In the case of DDR type RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the 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 amount of pixels the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core 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 fill rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.