Radeon HD 4830 1GB vs Radeon HD 4850 X2 512MB

Intro

Compare those specs to the Radeon HD 4850 X2 512MB, which comes with a core clock frequency of 625 MHz and a GDDR3 memory frequency of 993 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

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 1GB		95 Watts
Radeon HD 4850 X2 512MB		250 Watts
	Difference: 155 Watts (163%)

Memory Bandwidth

Performance-wise, the Radeon HD 4850 X2 512MB should theoretically be much superior to the Radeon HD 4830 1GB overall. (explain)

Radeon HD 4850 X2 512MB		127104 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 69504 (121%)

Texel Rate

The Radeon HD 4850 X2 512MB will be much (approximately 172%) faster with regards to anisotropic filtering than the Radeon HD 4830 1GB. (explain)

Radeon HD 4850 X2 512MB		50000 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 31600 (172%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon HD 4850 X2 512MB is a better choice, by a large margin. (explain)

Radeon HD 4850 X2 512MB		20000 Mpixels/sec
Radeon HD 4830 1GB		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 maximum amount of data (counted in MB per second) that can be moved across the external memory interface within a second. The number is calculated by multiplying the card's interface width by its memory speed. If it uses DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the better 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 number of texture map elements (texels) that can be applied in one second. This number is calculated by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.