There Are No Performance Gains With DRAM Faster Than 1600 MT/s
The answer to this depends on many factors. It is completely false if you are using a CPU's or APU’s on-board graphics. They use your system DRAM—and the faster, the better!
Most DRAM benchmarks measure read, write and copy performance. Many gaming benchmarks demonstrate a 3 to 5 FPS gain on DRAM between 1600 and 2133 MT/s. That’s because, in most games, DRAM is used primarily as a pipeline to feed information to the GPU and as a holding area for frequently retrieved data. The fact remains that it can increase FPS a little. Because the price of DRAM between 1600 and 2133 MT/s is only narrowly differentiated, it can sometimes still make sense to get the higher data rate DRAM.
Furthermore, the file compression program WinRAR pulls the data into DRAM and compresses it to DRAM before writing it back to the drive. Benchmarks using WinRAR can show a 25-percent gain going from 1600 MT/s to 2400. And there are plenty of other memory-intensive applications: editing video, working with images, CAD, running VMs and so on. While some of the gains might be small, the little snippets of savings add up if you use those applications.
If you are doing one task at a time—writing a memo, then browsing a Web page and then watching a video—you don’t really need faster DRAM. If you multitask, however—for instance, if you have a bunch of browser tabs open while you're working on a good-size spreadsheet, or if you're running video in a window, are working with images and maybe running a virus or malware scan in the background—then the faster memory can be far more beneficial.
You can test this out by running some applications like these with 1600 MT/s DRAM and then something faster. Once you’ve loaded up your system with several programs, use something like the SiSoftware Sandra system benchmark, and then use WinRAR on a large file. While it runs, hop around through your open Windows, and then check your scores in Sandra and the elapsed time for the WinRAR.