Intel Pentium 4 2.0GHz: The clock strikes two

The future: 133MHz FSB?

Lately Rambus has been talking about yields doing so well on PC800 RDRAM that they are actually capable of running the modules at 533MHz or at PC1066 spec.  There is actually a bit of significance about that number since Intel has been toying with the idea of increasing the FSB on the Pentium 4 from 100MHz to 133MHz, resulting in an effective 533MHz FSB. 

Just to satisfy our own curiosities we used our unlocked Pentium 4 to obtain benchmarks at 20 x 100MHz (2.0GHz) and 15 x 133MHz (2.0GHz) to see the benefit a 133MHz FSB would have on the Pentium 4’s performance.  In order to keep this a controlled experiment we decreased the RDRAM multiplier to 3x which kept the RDRAM frequency at 400MHz (100MHz x 4 vs. 133MHz x 3) or PC800. 

We ran the entire set of benchmarks featured in this review and normalized the results to the regular Pentium 4 2.0GHz running at 20 x 100MHz. 

The results are actually quite impressive.  On average, performance improved 6% across the board.  In some cases such as under Office Bench and SYSMark 2001 the improvement was significantly higher than the average (12 – 14%) while in other cases such as under 3D Studio MAX and CINEMA 4D there were no tangible performance gains.  The test platform ran flawlessly using the 133MHz FSB meaning that it shouldn’t be hard to implement.  Unfortunately for Intel, it’s unlikely that we’ll see the Northwood core debut with 133MHz FSB support.  It will probably be 2002 before we see the first 133MHz FSB Pentium 4 processors.  The performance difference between the 100MHz and 133MHz FSB will only increase as the Pentium 4’s clock speed goes up meaning that the performance benefits will improve with higher clock speed Pentium 4s.