GeForce GT 420 vs Radeon R9 M390X

Intro

Compare those specifications to the Radeon R9 M390X, which uses a 28 nm design. AMD has clocked the core frequency at 723 MHz. The GDDR5 RAM is set to run at a speed of 1250 MHz on this specific model. It features 2048 SPUs as well as 128 Texture Address Units and 32 Rasterization Operator Units.

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 is 456% faster than the GeForce GT 420 in general, because of its higher bandwidth. (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%) faster with regards to anisotropic filtering than the GeForce GT 420. (explain)

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

Pixel Rate

If running with a high screen resolution is important to you, then the Radeon R9 M390X is the winner, and very much so. (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 transferred over the external memory interface within a second. The number is calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR memory, the result 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 high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics 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 the graphics card can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.