Generally speaking, the faster the processor, the higher the system-wide bandwidth and the lower the latency. As is always the case, faster is better when it comes to processors, as we’ll see below. But with Core i7, the game changes up a bit.
Whereas previous memory controllers utilized a dual-channel operation, Intel threw that out the window to introduce triple-channel, which we talked a lot about at August’s IDF. Further, since Intel integrates the IMC onto the die of the new CPUs, benefits are going to be seen all-around.
Before jumping into the results, we already had an idea of what to expect, and just as we did, the results seen are nothing short of staggering.
Mentioned earlier, the improved design of Sandy Bridge should give us far better memory latencies compared to Clarkdale, and sure enough, that’s true. In fact, the latencies we see are some of the best we’ve come across, and in terms of bandwidth, that’s also been amped up.
How fast can one core swap data with another? It might not seem that important, but it definitely is if you are dealing with a true multi-threaded application. The faster data can be swapped around, the faster it’s going to be finished, so overall, inter-core speeds are important in every regard.
Even without looking at the data, we know that Core i7 is going to excel here, for a few different reasons. The main is the fact that this is Intel’s first native Quad-Core. Rather than have two Dual-Core dies placed beside each other, i7 was built to place four cores together, so that in itself improves things. Past that, the ultra-fast QPI bus likely also has something to do with speed increases.
While memory latencies are impressive, the results here are a strange turn of events. The inter-core bandwidth and latencies are actually worsened compared to Clarkdale and other Intel offerings. Fortunately this hasn’t been reflected in our other results.