Memory Speed Performance
To see how much of an impact the speed of the RAM has on Photoshop CS6, we simply ran our benchmark series each set of RAM (1333, 1600, 1866 and 2133 MHz) and compared them to each other. Half of the effects we are using utilize GPU acceleration, while the other half do not. So in addition to looking at the overall performance changes, we will also take a closer look at both of these types of effects individually.
As we stated in the test setup, we will also be using both a 109MB image as well as a 250MB version of our test image. This will let us see if any changes in performance become more pronounced as the image size is increased.
Starting with the Z77 test system, we saw a slight overall performance increase moving from 1333MHz to 1600MHz (about 1.3%), but very little performance increase after that. The X79 system on the other hand showed an increase in performance all the way up to 2133MHz. These performance gains are very small, however, with only about a .6% difference between the 1600MHz and 2133MHz RAM.
When we separate the GPU accelerated effects from the standard effects, we get some really interesting results. The GPU accelerated effects clearly show the advantages of using faster RAM, but the standard effects show virtually no difference at all. This is really good to know since it tells us that for medium-sized images (in this case 109MB) faster RAM only affects GPU accelerated effects. Even then, the difference is small (about 1-2%) as long as you are using RAM faster than 1333Mhz.
For both the Z77 and X79 test systems, we see almost exactly the same performance differences for the 250MB image that we saw previously for the 109MB image. The measured time difference is larger since the effects simply take longer to run on larger images, but the percentage difference is within a few tenths of a percent. This applies to not only the overall benchmark times, but the times for both the GPU Accelerated and Standard effects as well.
Our testing has shown that 1866 and 2133MHz RAM does not provide a significant increase in Photoshop CS6 performance, and since most Intel CPUs natively support RAM up to DDR3-1600MHz, that is the speed of RAM we would recommend using. RAM that operates at faster speeds than the CPU natively supports tend to have an increased risk of failure, and in our opinion the small performance improvements are not worth the risk.