Radeon HD 4750 vs Radeon HD 4850 1GB

Intro

Compare all of that to the Radeon HD 4850 1GB, which comes with GPU clock speed of 625 MHz, and 1024 MB of GDDR4 memory set to run at 993 MHz through a 256-bit bus. It also is made up of 800(160x5) Stream Processors, 40 Texture Address Units, and 16 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4750		75 Watts
Radeon HD 4850 1GB		110 Watts
	Difference: 35 Watts (47%)

Memory Bandwidth

The Radeon HD 4850 1GB, in theory, should perform a lot faster than the Radeon HD 4750 overall. (explain)

Radeon HD 4850 1GB		63552 MB/sec
Radeon HD 4750		51200 MB/sec
	Difference: 12352 (24%)

Texel Rate

The Radeon HD 4850 1GB is a little bit (more or less 7%) better at texture filtering than the Radeon HD 4750. (explain)

Radeon HD 4850 1GB		25000 Mtexels/sec
Radeon HD 4750		23360 Mtexels/sec
	Difference: 1640 (7%)

Pixel Rate

The Radeon HD 4750 is just a bit (more or less 17%) more effective at FSAA than the Radeon HD 4850 1GB, and should be capable of handling higher screen resolutions without slowing down too much. (explain)

Radeon HD 4750		11680 Mpixels/sec
Radeon HD 4850 1GB		10000 Mpixels/sec
	Difference: 1680 (17%)

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 largest amount of data (in units of megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied in one second. This figure is worked out by multiplying the total texture units of the card by the core speed of the chip. The better the texel rate, the better the video 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 the video card could possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.