Memory Configuration Performance
Testing how the memory configuration affects the performance of Photoshop CS6 is not as easy as testing how the speed of the RAM affects performance, but it is certainly possible. Unfortunately, the results are a little bit messy and require some effort to see exactly what is going on.
To test the memory configuration, we decided to focus on both the number of memory channels being used and size of each stick of RAM. By testing with two and four 4GB sticks of RAM in our Z77 system and two, four, six, and eights 4GB sticks of RAM in our X79 system, we can see if there is any advantage of using more or less memory channels. Also, by testing two and four 8GB sticks of RAM in both of the test systems, we can see if there is any advantage to using more 4GB sticks or fewer 8GB sticks to achieve the same total amount of memory in a system.
Starting with the Z77 system, we saw pretty much no change in performance moving from two to four sticks of RAM. With X79, however, there was a .6% increase in performance moving from two to four sticks, but only a .25% performance increase moving from both four to six sticks and six to eight sticks. Interestingly, this once again appears to mostly affect GPU accelerated effects and leaving the standard effects almost completely unchanged. So while the number of RAM sticks doesn't appear to matter for Z77 systems, X79 systems do get a small performance advantage by using four sticks of RAM versus two sticks. After that, the increase in performance is so small that it is not worth worrying about.
As for the size of the memory, our testing shows that there is no change in performance by using larger physical sticks of RAM. So if you are going for the absolute best performance possible for this size of images, you are slightly better off going with more 4GB sticks than fewer 8GB sticks. Whether a performance increase that is smaller than 1% on GPU accelerated effects is worth the more limited upgradability is something that each user will have to decide for themselves.
Upping the image size to 250MB shows similar results to the benchmarks with the 109MB image. The Z77 system in particular shows pretty much no difference going from two to four sticks of RAM. The results for the X79 system on the other hand, are slightly different. This time, moving from four to six sticks does not show any performance increase at all. Going up to eight sticks, however, does show a small .3% increase in performance. So for X79 systems, there is once again a small performance increase going with four sticks over two sticks, but after that the increase in performance is so small that it is not worth worrying about.
As for the size of the memory, our testing once again shows that there is no change in performance by using larger sticks of RAM. So if you are going for the absolute best performance possible, you are again slightly better off going with more 4GB sticks rather than fewer 8GB sticks. Again, a performance increase that is smaller than 1% is likely not worth the more limited upgradability, but that is something that each user will have to decide on their own.