Back To Dual-Channel
Lynnfield (Core i5) and Bloomfield (Core i7) are different animals. While the latter supports triple-channel DDR3 memory configurations, the former loses one channel, bumping us back to the days of dual-channel configurations (officially at speeds of up to DDR3-1333, in the case of our setup here). Not that we're worried--Core i7 has more throughput than it can currently utilize, and we anticipate that this platform will similarly have plenty of memory bandwidth.
Specific to Asus' implementation are a couple of memory-oriented extras. The first is called MemOK!, which facilitates one-touch fail-safe presets whenever compatibility is a perceived issue. We don't have much information on what MemOK! does exactly (and we continued to have issues with one set of modules in particular), but we'll certainly dig deeper into the inner workings of this value-add when it comes time to review the retail hardware.
The second innovation is called Q-DIMM, though this one wasn't available on our pre-production engineering sample. But the concept is easy enough to imagine. You have two "clips" per DIMM slot, which lock the module in place with a snap. On the side closest to your graphics cards, the retail P7P55D Evo won't have the clips you see in our picture. Instead, the modules will slide into place and clip-in on the side closest to the board's edge. As a result, you won't need to yank your video card to swap/add modules. We've seen this issue avoided altogether by vendors shifting memory slots toward the edge a little more, freeing up room between DIMMs and the first PCI Express slot. However, this workaround does the trick, too.