IDF Taipei: Memory interleaving
Another good piece of news about the upcoming Core i7 processors is the fact that the memory will be overclockable on all models, as it's running in a separate "bus" to the CPU. This means that those that already have expensive DDR3 memory kits have nothing to worry about, as they'll get the most out of their current modules.
In other words, you can overclock and underclock your memory to fit whatever "bus" speed you'll run the CPU at, although we're not quite sure how the QPI will work when it comes to overclocking the Core i7 processors, as it's not quite like the traditional front side bus that Intel have been using to date.
Another neat feature is that you can run unmatched memory modules in your X58 motherboard, although you won't get quite the same performance as you would running matched modules. It's possible to run one, two and three way interleaving over all three memory channels. The interleave can be spread over multiple modules in the same channel, but the limitations is that the same channel can only appear in an interleave once.
The granularity is 64MB, in other words, the smallest size on one interleave would be 192MB, although it's unlikely that someone would end up with such a configuration, as the smallest DDR3 modules are 512MB. Again, this is good news for people planning to upgrade, as it's possible to run with unevenly configured memory, but according to Intel you get the best performance if you keep the same amount of memory in the same channel, although this doesn't mean the same size modules in each channel.
For example, if you own a 2x2GB DDR3 kit today, you can compliment it with a 2x1GB kit and split it into 2GB per channel for the best overall performance. This means that triple-channel memory kits might not be as popular as first expected and it could possibly upset a few memory manufacturers that hoped to sell a lot of triple-channel DDR3 memory kits.
