Radeon HD 4650 512MB vs Radeon HD 7850

Intro

Compare those specifications to the Radeon HD 7850, which makes use of a 28 nm design. AMD has set the core frequency at 860 MHz. The GDDR5 memory runs at a frequency of 1200 MHz on this card. It features 1024 SPUs as well as 64 TAUs and 32 Rasterization Operator Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4650 512MB		55 Watts
Radeon HD 7850		130 Watts
	Difference: 75 Watts (136%)

Memory Bandwidth

As far as performance goes, the Radeon HD 7850 should theoretically be a lot better than the Radeon HD 4650 512MB overall. (explain)

Radeon HD 7850		153600 MB/sec
Radeon HD 4650 512MB		16000 MB/sec
	Difference: 137600 (860%)

Texel Rate

The Radeon HD 7850 is quite a bit (about 187%) more effective at texture filtering than the Radeon HD 4650 512MB. (explain)

Radeon HD 7850		55040 Mtexels/sec
Radeon HD 4650 512MB		19200 Mtexels/sec
	Difference: 35840 (187%)

Pixel Rate

If running with high levels of AA is important to you, then the Radeon HD 7850 is the winner, and very much so. (explain)

Radeon HD 7850		27520 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 22720 (473%)

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 information (measured in megabytes per second) that can be transported over the external memory interface in a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, 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 figure is calculated by multiplying the total texture units by the core 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 card can possibly write 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 clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.