GeForce 8400 GS 512MB vs Radeon HD 7850

Intro

Compare that to the Radeon HD 7850, which comes with a clock speed of 860 MHz and a GDDR5 memory frequency of 1200 MHz. It also makes use of a 256-bit bus, and makes use of a 28 nm design. It is comprised of 1024 SPUs, 64 TAUs, and 32 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 8400 GS 512MB		40 Watts
Radeon HD 7850		130 Watts
	Difference: 90 Watts (225%)

Memory Bandwidth

The Radeon HD 7850 should theoretically perform much faster than the GeForce 8400 GS 512MB in general. (explain)

Radeon HD 7850		153600 MB/sec
GeForce 8400 GS 512MB		6400 MB/sec
	Difference: 147200 (2300%)

Texel Rate

The Radeon HD 7850 should be a lot (approximately 958%) better at texture filtering than the GeForce 8400 GS 512MB. (explain)

Radeon HD 7850		55040 Mtexels/sec
GeForce 8400 GS 512MB		5200 Mtexels/sec
	Difference: 49840 (958%)

Pixel Rate

The Radeon HD 7850 should be quite a bit (approximately 958%) better at full screen anti-aliasing than the GeForce 8400 GS 512MB, and also should be able to handle higher resolutions without losing too much performance. (explain)

Radeon HD 7850		27520 Mpixels/sec
GeForce 8400 GS 512MB		2600 Mpixels/sec
	Difference: 24920 (958%)

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 megabytes per second) that can be transported across the external memory interface in a second. The number is worked out by multiplying the card's bus width by the speed of its memory. In the case of DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the card's 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 processed in one second. This figure is worked out by multiplying the total number of texture units by the core clock speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.

Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.