Before you nod off to sleep and plant your face in the keyboard, realize that this CPU is actually a pair of chips wound up to 3.73GHz and, well, that's a lot and stuff. Perhaps more importantly, thanks to refinements to its 65-nanometer manufacturing process, Intel has found a way to crank up the clock frequency while dialing back the heat on this double-barreled blowtorch of death. In fact, it's more like a blowtorch of pain now, with power consumption actually reduced from the Pentium Extreme Edition 955 we reviewed a few months back, despite the 965's increased clock speed.
The result could be that this CPU based on a lame-duck microarchitecture manages to do something few Pentiums have done in recent times: catch up with the competition from AMD in terms of performance and power use. And if that doesn't work, we can always try turning up the clock speed to 4.53GHz, right? Let's have a look at what Intel's new fastest processor has to offer.
The 965 takes a bow
For the unfamiliar, Pentium Extreme Edition processors are Intel's flagship desktop products, the top-of-the-line fastest CPUs it sells, traditionally priced just one buck shy of a cool thousand. The Extreme Edition 965 is primarily distinguished from the previous model 955 by its higher 3.73GHz clock speed. Like the rest of the Pentium D 900 series, Intel manufactures these chips using its 65nm fabrication process, and although they're billed as dual-core processors, they're really more like Siamese twins, with a pair of identical Pentium 4 "Cedar Mill" chips arranged together in one package. Each "core" is an independent CPU, complete with its own 2MB of L2 cache onboard.
Because the 965 is an Extreme Edition, though, it has a few extras the Pentium D 900 series lacks. The 965 comes with official support for a 1066MHz front-side bus, allowing it to talk to the rest of the systemand its two cores to one anotherat an accelerated pace. Dual-core Extreme Editions also have support for Hyper-Threading, which creates an irresistible bragging-rights scenario. Fire up Windows Task Manager or the like, and you'll see four virtual CPUs showing on this single-socket wonder. If that's not enough to impress your friends, perhaps the Extreme Edition's unlocked multiplier will do the trick. This thing overclocks easily with no need for bus speed adjustments or running the rest of the system at odd frequencies. Heck, the Intel motherboard we used for this review comes complete with easy BIOS-based multiplier adjustments and fine-grained control over CPU overvolting. (There was a day when the impact of those words would have bordered on cataclysmic, but now, such things are practically expected, even from Intel.)
The Pentium Extreme Edition 965 processor comes in a standard LGA775 package The 965 has also learned a trick the 955 didn't know: the enhanced "C1E" halt state that kicks in when the operating system lets the CPU know it can sit idle briefly. C1E turns down the CPU clock frequency dynamically, conserving power and reducing heat production. Previous Pentium 4 and D processors came with C1E halt state, but it wasn't implemented in Intel's earlier production 65nm processors. This useful mechanism makes a return in recent steppings of the 965, including the one we received for review. When idle, this puppy eases back its clock rate to 3.2GHz. The 965 still doesn't work with Intel's Enhanced SpeedStep clock throttling tech, but that's hardly a major drawback given the minimal practical differences between C1E and SpeedStep.
Here's your morsel of Moore's Law food for thought for the day: the Extreme Edition 965 is literally twice the CPU of the Pentium 4 Extreme Edition 3.73GHz introduced just a little more than a year ago. The P4 Extreme Edition 3.73GHz was a single-core 90nm chip based on the same NetBurst microarchitecture, with the same 2MB of L2 cache, the same 1066MHz front-side bus, and obviously the same 3.73GHz clock speed. Only thing is, each of the Extreme Edition 965's two cores have faster L2 caches than older 90nm processors, so the 965 is a little more than double the fun. Not bad for a year's progress, huh?