Radeon HD 4830 1GB vs Radeon HD 4850 2GB

Intro

Compare that to the Radeon HD 4850 2GB, which uses a 55 nm design. AMD has set the core frequency at 625 MHz. The GDDR4 RAM works at a frequency of 993 MHz on this particular model. It features 800(160x5) SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4830 1GB		95 Watts
Radeon HD 4850 2GB		110 Watts
	Difference: 15 Watts (16%)

Memory Bandwidth

In theory, the Radeon HD 4850 2GB should perform a little bit faster than the Radeon HD 4830 1GB overall. (explain)

Radeon HD 4850 2GB		63552 MB/sec
Radeon HD 4830 1GB		57600 MB/sec
	Difference: 5952 (10%)

Texel Rate

The Radeon HD 4850 2GB is a lot (about 36%) faster with regards to anisotropic filtering than the Radeon HD 4830 1GB. (explain)

Radeon HD 4850 2GB		25000 Mtexels/sec
Radeon HD 4830 1GB		18400 Mtexels/sec
	Difference: 6600 (36%)

Pixel Rate

The Radeon HD 4850 2GB will be a small bit (approximately 9%) more effective at AA than the Radeon HD 4830 1GB, and also will be able to handle higher resolutions better. (explain)

Radeon HD 4850 2GB		10000 Mpixels/sec
Radeon HD 4830 1GB		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 max amount of information (in units of MB per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the interface width by its memory clock speed. If it uses DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's 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 amount of texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total number of texture units by the core clock 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 per second.

Pixel Rate: Pixel rate is the most pixels the graphics card could 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 colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel 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.