Now that the clock speed war is over, AMD and Intel have been slowly improving the underlying architecture of their flagship processors. After all, a 200MHz clock speed improvement does little if there are other bottlenecks that are preventing the CPU from reaching optimal performance.
AMD has improved its Athlon XP processors recently by first incorporating a 333MHz bus last summer. The new bus speed was necessary at that time because AMD was having trouble scaling to clock speeds beyond 2.1GHz. By increasing the bus frequency, AMD was able to improve performance without having to resort to higher clock speeds, and thus was able to get around the manufacturing problems it was having. This “work smarter, not harder” approach was refined even further with the launch of AMD’s “Barton” Athlon XP core earlier this year. Barton doubled the L2 cache size from 256KB to 512KB, a move Intel had made earlier with its “Northwood” Pentium 4 core.
When it was originally conceived, Barton was intended to serve alongside AMD’s 64-bit desktop CPU, Athlon 64. This would give the Athlon XP one last upgrade path option, as initial Athlon 64 supply was expected to be light. Of course, we now know that Athlon 64 has been delayed until September, with volume shipments really kicking in at the end of the year and going into 2004. As a result, Barton has been pressed to hold the line for AMD; hence the chip received one final bus speed boost (400MHz) last month. AMD’s roadmap now lists Barton going through the end of 2004.
Intel has been playing its hand just as deftly. Besides the bus speed and cache improvements Intel incorporated into Northwood last year, the other big story from Intel was Hyper-Threading technology. Thanks to Hyper-Threading, the Pentium 4 can execute multiple software threads at once, just like a system with dual processors. Before Hyper-Threading, execution units would often go unused, sitting idle until needed. In its current form, Hyper-Threading works by sending a second thread to the processor with the intent that some of these idle units can be put to work, increasing the efficiency and performance of the processor. Hyper-Threading can also play dividends in multi-tasking situations as well.
Intel fine-tuned the Pentium 4 platform just two months ago with the introduction of a faster 800MHz system bus on its Pentium 4 3.0C. When paired with the 875P chipset and dual-channel DDR400 memory, we saw performance improvements of up to nine percent – roughly the equivalent of the 133MHz clock speed jumps Intel had been incorporating in each new Pentium 4 release.
Intel’s Springdale launch brought 800MHz bliss to the mainstream segment, and was accompanied by 2.4GHz, 2.6GHz, and 2.8GHz Pentium 4 “C” processors. This brought all of Intel’s latest technologies (including Hyper-Threading) to even the most cost-conscious consumer.
Now that Intel has seeded all segments of the PC market with state-of-the-art hardware, they’ve decided to address clock speed once again with today’s release of the Pentium 4 3.2GHz. Lets take a look at what’s new with this processor.