Intel's Pentium Performance Hangs on a Hyper-Thread

Non-intentional Benefits For HT-ready Applications

Several applications exist today that will benefit from HT, but the developers were not aware of the potential HT benefit when writing the programs, such as Adobe PhotoShop and Windows Media Decoder.

While many applications were written specifically for multithreaded dual processors applications, some multithreads were added by developers as a convenience for the software vendors when they were debugging their code. Because the debuggers had dual processor workstations and were writing with multiple threads, the debugging process worked faster. The end-user with a single-threaded environment obviously didn't see the benefit of that, but after turning on HT, you see it. Now, all of a sudden, these applications are better in a stand-alone mode.

The Pentium 4 Trojan Horse?

But for some observers, HT will help the Pentium 4 compensate for several of the less-than-stellar performance benchmarks associated with the Pentium 4 vs. the Athlon and the Pentium 3.

One of the most well known features of the new Pentium 4 is its extremely long pipeline. The pipeline of Pentium III, for example, has 10 stages and the Athlon has 11. Meanwhile, the Pentium 4 has no less than 20 stages. Due to the Pentium 4's long pipe architecture, performance has lagged megahertz for megahertz compared to the Pentium 3 and the Athlon for most office applications (an issue on which AMD has tried to capitalize with its AthlonXP line since its introduction last year).

The performance gap has even triggered ongoing class action lawsuits. This summer, class-action lawyers sued Intel, Gateway, and Hewlett-Packard. Technically, the suit includes anybody in the U.S. who had ever bought or leased a PC containing with a Pentium 4. Potentially, the plaintiffs may number hundreds of thousands of people. But now, Intel says HT enables its long pipeline architecture to see its full fruition. Could HT be Intel's Trojan Horse that will render the Pentium 4's performance commensurate with its clock-speed?