Our investigation of the correlation between the performance of Ivy Bridge platforms and their memory subsystem parameters suggests a lack of significant differences from Intel’s earlier platforms. The Ivy Bridge memory controller is largely the same as the Sandy Bridge one and delivers similar performance at the same settings. So, the influence of system memory settings on practical tasks is rather low. However, the new CPUs have brought about certain changes, the most important of which is the opportunity to choose a very high clock rate for DDR3 SDRAM. Such clock rates were not possible even with overclocker-targeted systems of the previous generation. As a result, the range of DDR3 SDRAM offered for LGA1155 systems has been extended, increasing the gap between configurations with slow and fast memory. By changing the memory clock rate alone, you can see a performance boost of 5-10% while applications that need large amounts of data (such as games) may get up to 20-30% faster! So, choosing the right kind of memory for you LGA1155 platform is important. We must note, however, that such benefits can only be achieved after a twofold increase in clock rate whereas a single 266MHz step up leads to a mere 2-3% increase in speed.
So, the rational approach to choosing system memory is in looking for the optimal frequency/price ratio. Modules up to DDR3-2133 SDRAM may be recommended for Ivy Bridge platforms, but not faster ones. Up to that frequency, the price remains reasonable while the performance in everyday applications grows up. Faster memory modules are considerably more expensive without providing tangible performance benefits, so they can only be recommended for enthusiasts who want maximum speed no matter what.
You shouldn’t bother about memory with low latencies, by the way. There are fewer such products on the market nowadays because low timings do not offer much in terms of performance on the modern LGA1155 platform.