GeForce GTX 650 vs Radeon HD 3870 1GB

Intro

Compare all that to the Radeon HD 3870 1GB, which comes with a clock speed of 775 MHz and a GDDR4 memory speed of 1125 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It is made up of 320(64x5) SPUs, 16 TAUs, and 16 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GTX 650		64 Watts
Radeon HD 3870 1GB		106 Watts
	Difference: 42 Watts (66%)

Memory Bandwidth

Theoretically speaking, the GeForce GTX 650 will be 11% quicker than the Radeon HD 3870 1GB in general, because of its greater data rate. (explain)

GeForce GTX 650		80000 MB/sec
Radeon HD 3870 1GB		72000 MB/sec
	Difference: 8000 (11%)

Texel Rate

The GeForce GTX 650 will be much (more or less 173%) more effective at anisotropic filtering than the Radeon HD 3870 1GB. (explain)

GeForce GTX 650		33856 Mtexels/sec
Radeon HD 3870 1GB		12400 Mtexels/sec
	Difference: 21456 (173%)

Pixel Rate

If using a high screen resolution is important to you, then the GeForce GTX 650 is a better choice, by far. (explain)

GeForce GTX 650		16928 Mpixels/sec
Radeon HD 3870 1GB		12400 Mpixels/sec
	Difference: 4528 (37%)

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 maximum amount of data (in units of MB per second) that can be transported past the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory speed. If the card has DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.

Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.

Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Render Output Units 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 fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.