For years now, memory vendors like Corsair, OCZ, and Kingston have been marketing "enthusiast" memory with ratings far beyond JEDEC specifications. But there's a catch: most of those memory modules need a little extra voltage to run at their rated specs. That usually doesn't pose a problem on decent motherboards, but it could become a serious issue once Intel's Core i7 arrives.
As reported by Custom PC, Asus' upcoming P6T Deluxe motherboard has a sticker covering its DIMM slots that says, "According to Intel CPU spec, DIMMs with voltage setting over 1.65V may damage the CPU permanently. We recommend you install the DIMMs with the voltage setting below 1.65V." Asus spokesman Iain Bristow talked to Custom PC about the issue, and he added that "the sticker had been placed on the motherboard after Intel's recommendation."
The memory controllers inside Core i7 CPUs support DDR3 memory, and JEDEC specifies a standard voltage of 1.5V for that memory type, so this 1.65V limit would leave very little leeway for overvolting. It could force consumers to shop carefully for their high-end DDR3 RAM, too. A quick search for DDR3-1600 modules at Newegg today shows only one of the 20 cheapest offerings with a voltage rating below 1.65V. Many other modules need up to 1.9V to reach their rated speeds.
With that said, Core i7 users probably won't run into too many bottlenecks. Not only does Intel's Nehalem architecture promise significant clock-for-clock performance improvements over current processors, but the first Core i7 variants should support three channels of DDR3-1333 RAM—all on a low-latency, integrated memory controller.