Tom's Hardware's 2009 Gift Guide: Part 1, For System Builders

Processor: Intel Core i5-750

www.intel.com
$199
By: William Van Winkle

Santa might whip up free toys for kids, but the rest of us have to pay with cash or credit, and that means the winter sky is not the limit. We’d all love to put a Core i7-975 Extreme in every stocking, but at a grand a pop, that’d be pretty ho-ho-horrific on the budget. If you want to give the gift of Intel's Nehalem architecture at 20% of the price, look no further than its Core i5-750.

To know where and why Core i5 fits into the big value scheme, we need to revisit the ghosts of Nehalem past. Originally, there was the king, Core i7 on an LGA 1366 socket interface. This monster features four cores with Hyper-Threading, yielding eight logical cores. You also have 8MB of L3 cache shared among all four physical cores and a three-channel DDR3 memory controller built into the CPU. For more on Intel's current flagship, check out our review of the Core i7-975.

Next, we got Core i7 on the LGA 1156 socket. What’s the difference? Not much! In fact, the derivative architecture was so good that we called it Intel's Mainstream Magnum Opus in our launch coverage. It included the same number of cores, Hyper-Threading as a feature of the Core i7s, and the same shared L3 cache. You merely step down to a dual-channel integrated DDR3 controller. And sure, the LGA 1366 variant gets 36 lanes of PCI Express 2.0 through X58 versus 16 built into the LGA 1136-based processor. But this is only a concern if you focus on multiple high-speed graphics cards across multiple slots.

The difference between i5 and i7 is Hyper-Threading and a bit of core clock rate. That’s it. The bottom line is that stepping down from three DDR3 channels to two and losing Hyper-Threading will generally whack 10% to 20% in performance versus today’s flagship. If that sounds grim, I’ll put it another way: you can get better than 80% of the top-end Core i7's performance for 20% of the price in a Core i5. Happy holidays, indeed!

Keep in mind that Core i5 preserves Nehalem’s Turbo Boost capabilities, which shuts down unneeded cores and uses some of their overhead to "overclock" the remaining core. Turbo Boost will take the i5-750's default speed of 2.66 GHz up to 3.2 GHz when running a single-threaded workload. Or, if you're comfortable taking the manual approach, we've taken these CPUs beyond 4GHz thanks to the maturity of Intel's 45nm manufacturing process, too.

Much (if not most) of your software may not need the eight-threaded support that Hyper-Threading—four might be plenty. The fact is that for the majority of mainstream users, Core i5-750 is an almost unbelievably good value—so good that it’s hard to justify paying more for anything until we see what Intel’s next-gen Gulftown (32nm, six physical cores) adds when it pops up in the middle of next year.