The study of the memory controller in the new Sandy Bridge-E processors produced unexpected and at the same time very interesting results. It turned out that this time Intel used a totally different approach to optimizing the work of the memory sub-system. The main idea of this approach was to optimize the quad-channel DDR3 SDRAM controller not for single-threaded but for multi-threaded load, which is more typical of the servers and high-performance workstations. Therefore, the Sandy Bridge-E memory controller doesn’t look too good in traditional desktop benchmarks. However, the new system simply blows you away by its unprecedented practical bandwidth in special tests such as Stream, for instance.
Unfortunately, this is bad news for the desktop users. Most typical desktop applications do not address the memory in multiple parallel threads. Therefore, we have quite a paradox in reality, when quad-channel memory access provides minimal or no benefits. Even though it may seem unbelievable, you will get practically the same performance if you use a dual- or triple-channel DDR3 SDRAM in your LGA 2011 system instead of a special quad-channel kit.
This may be a pretty useful piece of information for those users, who do not feel like upgrading their memory. They will experience truly minimal performance loss if they decide to give up quad-channel memory access.
The most important parameter for the memory sub-system in the new LGA 2011 platforms is certainly DDR3 SDRAM frequency. This parameter has a great effect on the overall system performance than the number of channel, and a much greater effect than the latencies. Therefore, you should pay special attention to this particular parameter while shopping around for memory for your LGA 2011 system. In fact, this is no news at this point: the same priority was in place for other platforms with DDR3 SDRAM, too. The overclocker memory makers are well aware of this that is why they have given up the hunt for lower timings and are focusing mostly on hitting higher frequencies.
LGA 2011 platform favors memory overclocking and allows achieving stability at pretty high DDR3 speeds. Now that the prices on DIMM modules are crashing down, it is a good chance for the manufacturers to make some money off their more expensive elite DDR3 kits. However, don’t be misled by aggressive marketing. The importance of high memory frequency, which we stated earlier, is a relative factor. In fact, the Sandy Bridge-E platform performance only depend so much on the memory frequency and even if you put in the fastest memory out there, you gain may not exceed a few percent. So, we suggest investing into expensive high-speed memory in the end, when all other system components have been upgraded to the ideal choices.