Radeon HD 4870 512MB vs Radeon R9 M380

Intro

Compare that to the Radeon R9 M380, which features a clock frequency of 1000 MHz and a GDDR5 memory speed of 1500 MHz. It also features a 128-bit memory bus, and uses a 28 nm design. It is made up of 640 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.

Display Graphs

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Power Usage and Theoretical Benchmarks

Memory Bandwidth

Theoretically speaking, the Radeon HD 4870 512MB is 20% quicker than the Radeon R9 M380 overall, because of its higher data rate. (explain)

Radeon HD 4870 512MB		115200 MB/sec
Radeon R9 M380		96000 MB/sec
	Difference: 19200 (20%)

Texel Rate

The Radeon R9 M380 will be quite a bit (approximately 33%) faster with regards to AF than the Radeon HD 4870 512MB. (explain)

Radeon R9 M380		40000 Mtexels/sec
Radeon HD 4870 512MB		30000 Mtexels/sec
	Difference: 10000 (33%)

Pixel Rate

The Radeon R9 M380 is a lot (more or less 33%) more effective at FSAA than the Radeon HD 4870 512MB, and will be able to handle higher screen resolutions without losing too much performance. (explain)

Radeon R9 M380		16000 Mpixels/sec
Radeon HD 4870 512MB		12000 Mpixels/sec
	Difference: 4000 (33%)

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 largest amount of data (measured in megabytes per second) that can be transferred over the external memory interface in a second. It is worked out by multiplying the interface width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 again. If it uses 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, High Dynamic Range and high resolutions.

Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total 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 in a second.

Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.