This 2.66GHz quad-core CPU, a member of Intel's Lynnfield family of chips, is based on the same characteristics as the previously mentioned Core i7-870 CPU, with one key difference: This CPU has no hyperthreading, its four physical cores are all you're going to get, rather than the eight "virtual cores" that would otherwise appear in your operating system when using a Core i7-870.
How much does that difference affect this $199 chip's performance? Our WorldBench 6 tests showed a 17 percent drop by the i5-750 from the i7-870, which is almost double the 9 percent difference between the two CPUs' stock clock speeds (the i5-750, with Turbo Boost, can raise its frequency to 3.2GHz when needed). The difference on our multithreaded Cinebench test is more pronounced, as the i5-750 delivers a score 40 percent lower than that of the i7-870.
In addition to the chip's dual-channel memory controller (which means only four DIMM slots), the socket-1156 CPU's internal PCI Express controller can dish out one full x16 PCI-E connection for graphics or split two x8 connections. That won't affect your performance unless you plan to run a pair of graphics cards in parallel.
You don't get multithreaded processing power with the i5-750; as a result, this quad-core suffers on multitasking tests.