GeForce 840M vs Radeon HD 4650 512MB

Intro

Compare that to the Radeon HD 4650 512MB, which features a core clock frequency of 600 MHz and a DDR2 memory frequency of 500 MHz. It also features a 128-bit memory bus, and uses a 55 nm design. It is made up of 320(64x5) SPUs, 32 TAUs, and 8 Raster Operation Units.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce 840M		30 Watts
Radeon HD 4650 512MB		55 Watts
	Difference: 25 Watts (83%)

Memory Bandwidth

Both cards have exactly the same bandwidth, so theoretically they should have identical performance. (explain)

Texel Rate

The GeForce 840M is quite a bit (approximately 29%) better at anisotropic filtering than the Radeon HD 4650 512MB. (explain)

GeForce 840M		24696 Mtexels/sec
Radeon HD 4650 512MB		19200 Mtexels/sec
	Difference: 5496 (29%)

Pixel Rate

The GeForce 840M is quite a bit (approximately 72%) faster with regards to full screen anti-aliasing than the Radeon HD 4650 512MB, and also capable of handling higher resolutions more effectively. (explain)

GeForce 840M		8232 Mpixels/sec
Radeon HD 4650 512MB		4800 Mpixels/sec
	Difference: 3432 (72%)

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 maximum amount of data (measured in megabytes per second) that can be transferred across the external memory interface in one second. The number is calculated by multiplying the bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's 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 amount of texture map elements (texels) that can be applied per second. This number is worked out by multiplying the total amount of texture units 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 processed per second.

Pixel Rate: Pixel rate is the most pixels the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.