Radeon HD 4830 512MB vs Radeon HD 4850 X2 512MB

Intro

Compare all of that to the Radeon HD 4850 X2 512MB, which comes with a clock frequency of 625 MHz and a GDDR3 memory speed of 993 MHz. It also makes use of a 256-bit memory 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 4830 512MB		95 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 155 Watts (163%)

Memory Bandwidth

The Radeon HD 4850 X2 512MB should in theory be a lot faster than the Radeon HD 4830 512MB in general. (explain)

Radeon HD 4850 X2 512MB		127104 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 69504 (121%)

Texel Rate

The Radeon HD 4850 X2 512MB should be quite a bit (about 172%) faster with regards to anisotropic filtering than the Radeon HD 4830 512MB. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 31600 (172%)

Pixel Rate

If using lots of anti-aliasing is important to you, then the Radeon HD 4850 X2 512MB is a better choice, by far. (explain)

Radeon HD 4850 X2 512MB		20000 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 10800 (117%)

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 information (measured in MB per second) that can be transferred over the external memory interface in one second. It's worked out by multiplying the bus width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, 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 amount of texture map elements (texels) that are applied in one second. This is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). 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 potential to reach the maximum fill rate.