Radeon HD 4830 1GB vs Radeon HD 4850 2GB

Intro

Compare all that to the Radeon HD 4850 2GB, which features a core clock speed of 625 MHz and a GDDR4 memory speed of 993 MHz. It also features a 256-bit bus, and makes use of a 55 nm design. It features 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

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

The Radeon HD 4850 2GB, in theory, should perform just a 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 (approximately 36%) better at texture 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

If running with lots of anti-aliasing is important to you, then the Radeon HD 4850 2GB is a better choice, though only just barely. (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: Bandwidth is the maximum amount of data (in units of MB per second) that can be moved past the external memory interface in one second. The number is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This number is worked out by multiplying the total texture units by the core 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 in a second.

Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate 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 outputting the pixels (image) to the screen. The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.