Radeon HD 4850 X2 1GB vs Radeon HD 4870 1GB

Intro

Compare those specifications to the Radeon HD 4870 1GB, which features a core clock frequency of 750 MHz and a GDDR5 memory frequency of 900 MHz. It also features a 256-bit bus, and uses a 55 nm design. It is comprised of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4870 1GB		150 Watts
Radeon HD 4850 X2 1GB		250 Watts
	Difference: 100 Watts (67%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 4850 X2 1GB should be a small bit faster than the Radeon HD 4870 1GB overall. (explain)

Radeon HD 4850 X2 1GB		127104 MB/sec
Radeon HD 4870 1GB		115200 MB/sec
	Difference: 11904 (10%)

Texel Rate

The Radeon HD 4850 X2 1GB will be much (about 67%) faster with regards to anisotropic filtering than the Radeon HD 4870 1GB. (explain)

Radeon HD 4850 X2 1GB		50000 Mtexels/sec
Radeon HD 4870 1GB		30000 Mtexels/sec
	Difference: 20000 (67%)

Pixel Rate

If using a high resolution is important to you, then the Radeon HD 4850 X2 1GB is superior to the Radeon HD 4870 1GB, and very much so. (explain)

Radeon HD 4850 X2 1GB		20000 Mpixels/sec
Radeon HD 4870 1GB		12000 Mpixels/sec
	Difference: 8000 (67%)

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 max amount of data (measured in megabytes per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the interface width by the speed of its memory. If the card has 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 anti-aliasing, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This is calculated by multiplying the total number of texture units of the card by the core 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 applied in one second.

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