As mentioned we’d take another look at throttling as that is often a cause for performance drops. Throttling occurs when Pentium 4 processors aren’t cooled properly and thus heat up quickly, causing for the throttling mechanism to be triggered. Although many people will see this as a worst-case scenario that never actually happens throttling occurs more often than you’d think. The culprit? Intel’s stock heatsink that is shipped with all of their processors. This heatsink isn’t able to handle the heat production from a top-of-the-line Pentium 4 processor in all but a very roomy mid or full tower case. We’ve seen throttling occur on Intel’s Pentium 4 560 processor before, putting the brakes on performance, so we set out to explore how these new processors fared in comparison to the 500 and 500J series.
In the above graphs we’ve used Futuremark’s PCmark04 v1.30 as a benchmark and ran Panopsys’ ThrottleWatch
to determine if, and when, throttling occurred. As you can see from the graphs the Pentium 4 560 throttles by quite a significant margin, which reduced its benchmark score for that run significantly. The heatsink used is Intel’s stock heatsink and the entire PC is mounted in a run-of-the-mill mid tower, so this is very much a real-life scenario. But the Pentium 4 560 isn’t the only one that throttles, the Pentium 4 3.73GHz Extreme Edition throttles as well, although not as bad as the 560. Both the Pentium 4 570J and 660 however don’t throttle at all, but you can see both processors drop their clock speed when the processor load is reduced. So, what do these graphs tell us? The obvious conclusion to draw is that the stock heatsink Intel ships with its processors is not able to cool their top-of-the-line processors very well. It handles the Pentium 570J and 660 without throttling, but that’s due to the fact that these processors automatically lower their clock speed when the processor load is reduced, significantly lowering their heat production. What’s important to note is that if they don’t you’d see the same as with the 3.73GHz Extreme Edition, which in essence is a 600 series processor which lacks clock speed throttling and runs at full steam all the time.
So if you are shopping for a Pentium 4 processor, or a Pentium 4 based PC, go with a 600 series processor, as they offer better performance and features than the 500 or 500J series. We’d stay away from the Pentium 4 3.73GHz Extreme Edition processor, there’s nothing that justifies it price, as performance is only marginally better than the 660. The Pentium 4 660 is also the better processor for those that like to wring every last bit of performance from their PC. Our Pentium 4 660 had no problems with running at over 4GHz clock speed and was able to run stable at a maximum of 4.2GHz. Unfortunately the Pentium 4 3.73GHz Extreme Edition did not have much headroom left, 3.9GHz was as much as we could get out of it. Overall the Pentium 4 660 left a very favorable impression; it is easily the best Pentium 4 processor to date and as such deserves a recommendation.