Overclocking Intel’s Xeon E5620: Quad-Core 32 nm At 4+ GHz

From my review of Intel’s Core i7-980X:

“What’d really be cool for the enthusiast crowd would be a line of quad-core CPUs manufactured at 32 nm. Almost certainly scalable to even higher clock rates and armed with AES-NI, these would be high-performance, lower-power options that’d go really well with today’s less-expensive X58-based motherboards.

The potential for such a design is supported by Intel’s plans to launch quad-core 32 nm Xeon processors based on its Westmere-EP design. But the most we could get out of Intel regarding its desktop plans was ‘we’re considering all options.’ Ah well, we tried.”

Well, I give up on waiting. I’ve been poking Intel, trying to talk the company into introducing one of its 32 nm Xeons as a desktop chip. I want something faster than a Core i5-600-series chip and cheaper than a Core i7-970. Four cores are fine—just give the overclockers something that’ll run cool at 4+ GHz.

Is Xeon Where It’s At?

Meet the Xeon E5620. This processor runs at 2.4 GHz by default, and it Turbo Boosts up to 2.66 GHz. It’s a quad-core chip, but it retains all of Westmere-EP’s 12 MB shared L3 cache. Hyper-Threading is turned on, so you get up to eight threads in flight at a time, and the chip’s QPI operates at 5.86 GT/s.

Performance-wise, you can’t expect much out of a 2.4 GHz part. However, Xeons are binned notoriously generously, putting power and reliability ahead of all else. The 32 nm Xeon E5620 has a VID range of .75-1.35 V and sports a modest 80 W TDP.

The only Achilles heel this thing has is an 18x multiplier that’s locked. Oh, were it not for locked ratios, this $389 Xeon would be such a beast. Sigh.

Nevertheless, I got my hands on a pair of E5620s and shot for the moon, hoping to derive a bit of enthusiast value from a notoriously business-class processor designed for dual-socket servers and workstations. With a bit of help from Asus (not every X58 motherboard supports Xeon CPUs), I managed to build a fast, stable, gaming box that doesn’t require high-end cooling or eyebrow-raising BIOS settings.