Tuesday, April 17, 2007

Quad Core Nostalgia

As I watch Intel launch its latest quad-core CPU I can't help but wax nostalgic about my time as contract test engineer for the company's Desktop Architecture Labs (DAL). It was early 2000 and the first Pentium 4 was still in preproduction testing. I had just received my prototype system for evaluation - an 800Mhz box with dual-channel RAMBUS (remember those guys?) RDRAM. I knew they were in trouble when my first round of tests - mostly linear office productivity tasks - showed the chip to be 30-40% *slower* than its predecessor, the Pentium III. I communicated my findings back to Intel and they blamed it on a buggy BIOS and poorly tuned chipset.

Weeks later, as I evaluated the now 1.5GHz production-level chip, I became convinced that a traditional linear benchmark approach wasn't going to cut it. The Pentium 4's longer pipeline simply clobbered throughput, with most tests showing performance barely on par with the older P6 core. Fortunately, I was already hard at work on my first parallel-processing test suite, Benchmark Studio, and tests with multiple, concurrent tasks had the Pentium 4 pulling away from the Pentium III by a sizable margin.

Once again, I communicated my findings to Intel, even suggesting a possible marketing spin for the data: More performance for demanding workloads. It would have dovetailed nicely with the related work I had been doing around the company's "Constant Computing" initiative, however, ultimately my findings were canned. Apparently, my message of "more torque for heavy multitasking loads" (i.e. the "SUV" argument) wasn't sexy enough. They wanted a "sports car" message. Better linear performance. Ever higher clock speeds (4GHz was the long term goal). The rest, as they say, is history.

Of course, the Pentium 4 architecture (a.k.a. "NetBurst") ultimately flopped, allowing AMD to each Intel's lunch for many years. When Intel finally dumped NetBurst in favor of a revamped Pentium III design (a.k.a. Core 2), the industry had finally caught-up with where I was over 7 years ago. Now, virtually all business productivity benchmarks emphasize parallel execution performance, a necessity now that most CPUs have 2 or more cores on board. Symmetrical Multiprocessing (SMP), once the purview of engineering workstations, is now de rigeur, and the current mainstream OS - Windows XP - is completely at home on multiple CPUs.
I guess I can take some small measure of satisfaction in knowing that I was right about where benchmarking was headed, and that if Intel had followed my lead they might have fared better (at least in terms of marketing success).

Note: You can download the latest incarnation of my test suite, Clarity Studio, for free from the exo.performance.network (www.xpnet.com) web site. Read more...