Radeon HD 4650 512MB vs Radeon HD 7750

Intro

Compare those specifications to the Radeon HD 7750, which comes with core speeds of 800 MHz on the GPU, and 1125 MHz on the 1024 MB of GDDR5 RAM. It features 512 SPUs along with 32 Texture Address Units and 16 ROPs.

(No game benchmarks for this combination yet.)

Power Usage and Theoretical Benchmarks

Both cards have the same power consumption.

Memory Bandwidth

The Radeon HD 7750 should in theory be quite a bit faster than the Radeon HD 4650 512MB in general. (explain)

Radeon HD 7750		72000 MB/sec
Radeon HD 4650 512MB		16000 MB/sec
	Difference: 56000 (350%)

Texel Rate

The Radeon HD 7750 will be quite a bit (about 33%) better at anisotropic filtering than the Radeon HD 4650 512MB. (explain)

Radeon HD 7750		25600 Mtexels/sec
Radeon HD 4650 512MB		19200 Mtexels/sec
	Difference: 6400 (33%)

Pixel Rate

The Radeon HD 7750 is quite a bit (about 167%) faster with regards to FSAA than the Radeon HD 4650 512MB, and capable of handling higher screen resolutions while still performing well. (explain)

Radeon HD 7750		12800 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 8000 (167%)

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 (measured in MB per second) that can be transported over the external memory interface in a second. It is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied in one second. This is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics 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 maximum number of pixels that the graphics chip can possibly record to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.