GeForce GT 420 vs Radeon R9 M390X

Intro

Compare those specifications to the Radeon R9 M390X, which features a clock speed of 723 MHz and a GDDR5 memory frequency of 1250 MHz. It also uses a 256-bit bus, and makes use of a 28 nm design. It is made up of 2048 SPUs, 128 Texture Address Units, and 32 ROPs.

Display Graphs

Hide Graphs

Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

GeForce GT 420		50 Watts
Radeon R9 M390X		125 Watts
	Difference: 75 Watts (150%)

Memory Bandwidth

Theoretically speaking, the Radeon R9 M390X will be 456% quicker than the GeForce GT 420 overall, because of its greater data rate. (explain)

Radeon R9 M390X		160000 MB/sec
GeForce GT 420		28800 MB/sec
	Difference: 131200 (456%)

Texel Rate

The Radeon R9 M390X should be much (more or less 1553%) better at texture filtering than the GeForce GT 420. (explain)

Radeon R9 M390X		92544 Mtexels/sec
GeForce GT 420		5600 Mtexels/sec
	Difference: 86944 (1553%)

Pixel Rate

The Radeon R9 M390X will be quite a bit (about 726%) better at FSAA than the GeForce GT 420, and also capable of handling higher resolutions better. (explain)

Radeon R9 M390X		23136 Mpixels/sec
GeForce GT 420		2800 Mpixels/sec
	Difference: 20336 (726%)

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 (in units of megabytes per second) that can be transported over the external memory interface in one second. The number is worked out by multiplying the card's interface width by its memory clock speed. If it uses DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.

Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the video 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 write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the card's 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 lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.