As we already briefly discussed during our update yesterday the Pentium 4 is soon to be HyperThreading enabled and will debut at 3.06GHz this year. Because we were naturally curious as to what kind of performance and compatibility we can expect from the new Pentium 4, we’ve asked Bill Siu a number of questions to get an idea of what to expect. One thing that became clear right off the bat is the fact that current P4s already have HyperThreading hardware, it just isn’t enabled and won’t be in the future either as the 3.06GHz will be a new stepping of the Pentium 4 core which will implement the latest version of HyperThreading which might not be compatible with previous silicon.
Fig 1. Bill Siu discusses which OSs will be compatible with HyperThreading. This movie requires the Windows Media player to be installed and requires a broadband connection for streaming playback.
One other issue was also addressed by Bill Siu and that’s the question whether older OSs would be able to benefit from HyperThreading, which won’t be the case, only Windows XP will be able to profit from this new feature. Surprising though was the fact that Windows XP Home Edition will also be able to profit from this, although it does not have SMP support and is unable to use more than one processor. Thus unfortunately Windows 2000 and Windows ME users will not be able to profit from the extra performance.
Fig 2. Can HyperThreaded Pentium 4s be compared to real SMP systems such as the Xeon DP? This movie requires the Windows Media player to be installed and requires a broadband connection for streaming playback.
We’ve also asked Bill about the performance differences between a genuine SMP system, such as for example a Xeon DP and a system equipped with a single HyperThreaded Pentium 4. Bill was quick to comment that we’ll see a performance delta anywhere from 70% to virtually no gain if HyperThreading is enabled on a single CPU system but wasn’t sure whether it would be comparable to a SMP configuration. Naturally one of the benefits of HyperThreading vs. genuine SMP would obviously be that we’re not sharing the memory and system bandwidth between two CPUs and thus could be having a slight advantage.
Next update: IDF, Banias a New Mobile Architecture - 10-09-2002, 3:00pm