Radeon HD 4890 1GB vs Radeon HD 5850

Intro

Compare those specs to the Radeon HD 5850, which comes with GPU clock speed of 725 MHz, and 1024 MB of GDDR5 RAM set to run at 1000 MHz through a 256-bit bus. It also is made up of 1440(288x5) SPUs, 72 Texture Address Units, and 32 ROPs.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 5850		151 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 39 Watts (26%)

Memory Bandwidth

As far as performance goes, the Radeon HD 5850 should theoretically be a small bit better than the Radeon HD 4890 1GB overall. (explain)

Radeon HD 5850		128000 MB/sec
Radeon HD 4890 1GB		124800 MB/sec
	Difference: 3200 (3%)

Texel Rate

The Radeon HD 5850 should be quite a bit (more or less 31%) better at anisotropic filtering than the Radeon HD 4890 1GB. (explain)

Radeon HD 5850		52200 Mtexels/sec
Radeon HD 4890 1GB		40000 Mtexels/sec
	Difference: 12200 (31%)

Pixel Rate

The Radeon HD 5850 is much (more or less 45%) more effective at FSAA than the Radeon HD 4890 1GB, and also will be able to handle higher screen resolutions better. (explain)

Radeon HD 5850		23200 Mpixels/sec
Radeon HD 4890 1GB		16000 Mpixels/sec
	Difference: 7200 (45%)

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 largest amount of information (counted in megabytes per second) that can be transferred over the external memory interface within a second. It is worked out by multiplying the interface width by its memory speed. In the case of DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the 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 texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling 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 that the graphics chip could possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.