Radeon HD 4830 512MB vs Radeon HD 4850 1GB

Intro

Compare that to the Radeon HD 4850 1GB, which uses a 55 nm design. ATi has set the core speed at 625 MHz. The GDDR4 RAM runs at a frequency of 993 MHz on this particular model. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 512MB		95 Watts
Radeon HD 4850 1GB		110 Watts
	Difference: 15 Watts (16%)

Memory Bandwidth

The Radeon HD 4850 1GB should theoretically perform a little bit faster than the Radeon HD 4830 512MB overall. (explain)

Radeon HD 4850 1GB		63552 MB/sec
Radeon HD 4830 512MB		57600 MB/sec
	Difference: 5952 (10%)

Texel Rate

The Radeon HD 4850 1GB will be quite a bit (approximately 36%) faster with regards to anisotropic filtering than the Radeon HD 4830 512MB. (explain)

Radeon HD 4850 1GB		25000 Mtexels/sec
Radeon HD 4830 512MB		18400 Mtexels/sec
	Difference: 6600 (36%)

Pixel Rate

The Radeon HD 4850 1GB will be a little bit (more or less 9%) more effective at FSAA than the Radeon HD 4830 512MB, and also capable of handling higher resolutions better. (explain)

Radeon HD 4850 1GB		10000 Mpixels/sec
Radeon HD 4830 512MB		9200 Mpixels/sec
	Difference: 800 (9%)

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.

Price Comparison

Specifications

Memory Bandwidth: Memory bandwidth is the maximum amount of data (counted in MB per second) that can be moved across the external memory interface in one second. It is worked out by multiplying the bus width by its memory clock speed. If the card has DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate 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 outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.