Radeon HD 4890 1GB vs Radeon R9 M395X

Intro

Compare those specifications to the Radeon R9 M395X, which features GPU clock speed of 723 MHz, and 4096 MB of GDDR5 RAM set to run at 1250 MHz through a 256-bit bus. It also is made up of 2048 Stream Processors, 128 Texture Address Units, and 32 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Power Consumption (Max TDP)

Radeon R9 M395X		125 Watts
Radeon HD 4890 1GB		190 Watts
	Difference: 65 Watts (52%)

Memory Bandwidth

Theoretically, the Radeon R9 M395X should be much faster than the Radeon HD 4890 1GB in general. (explain)

Radeon R9 M395X		160000 MB/sec
Radeon HD 4890 1GB		124800 MB/sec
	Difference: 35200 (28%)

Texel Rate

The Radeon R9 M395X should be much (more or less 131%) faster with regards to AF than the Radeon HD 4890 1GB. (explain)

Radeon R9 M395X		92544 Mtexels/sec
Radeon HD 4890 1GB		40000 Mtexels/sec
	Difference: 52544 (131%)

Pixel Rate

If using a high screen resolution is important to you, then the Radeon R9 M395X is superior to the Radeon HD 4890 1GB, and very much so. (explain)

Radeon R9 M395X		23136 Mpixels/sec
Radeon HD 4890 1GB		16000 Mpixels/sec
	Difference: 7136 (45%)

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 max amount of data (in units of megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the card's 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 are processed per second. This number is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the video 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 number of pixels that the graphics chip could possibly record to its 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 the card's clock speed. ROPs (Raster Operations Pipelines - aka 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 of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.