Radeon HD 4650 512MB vs Radeon HD 6670 (OEM)

Intro

Compare all of that to the Radeon HD 6670 (OEM), which features a core clock speed of 800 MHz and a GDDR5 memory frequency of 1000 MHz. It also makes use of a 128-bit memory bus, and makes use of a 40 nm design. It is comprised of 480 SPUs, 24 Texture Address Units, and 8 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon HD 4650 512MB		55 Watts
Radeon HD 6670 (OEM)		63 Watts
	Difference: 8 Watts (15%)

Memory Bandwidth

Theoretically speaking, the Radeon HD 6670 (OEM) should be 300% quicker than the Radeon HD 4650 512MB overall, due to its higher data rate. (explain)

Radeon HD 6670 (OEM)		64000 MB/sec
Radeon HD 4650 512MB		16000 MB/sec
	Difference: 48000 (300%)

Texel Rate

Both cards have exactly the same texel fill rate, so in theory they should perform equally good at at AF. (explain)

Pixel Rate

If running with lots of anti-aliasing is important to you, then the Radeon HD 6670 (OEM) is the winner, and very much so. (explain)

Radeon HD 6670 (OEM)		6400 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 1600 (33%)

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 data (measured in megabytes per second) that can be moved across the external memory interface in one second. It's calculated by multiplying the interface width by the speed of its memory. If it uses DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher 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 are processed per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.