Another modification of the memory controller that happened during the launch of the new processors on Sandy Bridge microarchitecture deserves our most positive feedback. Intel engineers not only managed to fix the issues in the memory controller of the previous generation Westmere processors, but also to create a new controller, which turned out the highest performing of all existing modifications. Due to elimination of all major bottlenecks between the computational cores and the memory controller, Sandy Bridge proved to be more dependent on the specifications of the DDR3 SDRAM modules in the system than the predecessors or competitors.
However, it doesn’t change the situation in a larger scale. Every time when we discussed the effects of memory speed on the overall performance in certain configurations, we arrived at the conclusion that these effects were quite insignificant. This conclusion that we made back in the days for Socket AM3 and LGA1156 systems proved true one more time. It is also valid for Sandy Bridge based platforms and is backed up by the test results. The results show that the 266 MHz increase in the memory frequency produces only 2-4% growth in the average performance. And by setting all latencies one step lower we can only boost the performance by 1-2% at best.
However, all this doesn’t mean that you should disregard the need to make an educated decision on the best memory for your LGA1155 system. A slight practical effect from the use of faster memory is an average picture. At the same time, there are applications that work with large amounts of data and their performance depends much greater on the DDR3 SDRAM specifications. Among applications like that are, for example, some contemporary games, where you can gain a few extra frames per second by simply upgrading your memory.
This uncertainty together with pretty wide range of DDR3 SDRAM prices on modules with different specifications do not allow us to give specific recommendations regarding the best memory choices for Sandy Bridge platform. However, in general terms, you should keep in mind two things. Firstly, the memory frequency is of greater importance for the overall system performance than the memory timings. Secondly, the additional financial investments into faster memory may not pay back in the long run. In particular, high-speed DDR3-2133 and DDR3-1866 modules may cost 1.5-2 times more than the ordinary DDR3-1333 SDRAM.
Therefore, we believe that inexpensive DDR3-1600 SDRAM with not very aggressive timings would be the most reasonable choice for contemporary LGA1155 systems: in our opinion, memory like that offers the best price-to-performance ratio today.