Radeon HD 4650 512MB vs Radeon HD 5550

Intro

Compare those specifications to the Radeon HD 5550, which features a clock speed of 550 MHz and a DDR2 memory frequency of 400 MHz. It also uses a 128-bit memory bus, and uses a 40 nm design. It is comprised of 320(64x5) SPUs, 16 Texture Address Units, and 8 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Memory Bandwidth

The Radeon HD 4650 512MB, in theory, should perform a lot faster than the Radeon HD 5550 overall. (explain)

Radeon HD 4650 512MB		16000 MB/sec
Radeon HD 5550		12800 MB/sec
	Difference: 3200 (25%)

Texel Rate

The Radeon HD 4650 512MB should be much (more or less 118%) better at AF than the Radeon HD 5550. (explain)

Radeon HD 4650 512MB		19200 Mtexels/sec
Radeon HD 5550		8800 Mtexels/sec
	Difference: 10400 (118%)

Pixel Rate

The Radeon HD 4650 512MB is a small bit (approximately 9%) better at FSAA than the Radeon HD 5550, and also will be capable of handling higher resolutions without slowing down too much. (explain)

Radeon HD 4650 512MB		4800 Mpixels/sec
Radeon HD 5550		4400 Mpixels/sec
	Difference: 400 (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 (measured in megabytes per second) that can be transferred over the external memory interface in a second. It is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR memory, the result should 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, High Dynamic Range and high resolutions.

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

Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.