Hyper-Threading support will be available with all currently shipping motherboards that have support for the 533MHz FSB. Older motherboards based on the same chipset will also offer support after a BIOS update. For motherboards based on older chipsets such as the Intel 845B or the 845D there will probably no support. Which 3rd party chipsets will support Hyper-Threading remains yet to be seen, but it is to be expected that SiS’ chipsets will offer support too after a BIOS update.
Fig 4. The Asus P4T533-C motherboard, featuring dual channel PC1066 RDRAM, capable of 4.2GB/s.
The reasons for only offering support with the latest 533MHz FSB chipsets is twofold, the first reason is because Intel is phasing out the 400MHz FSB Pentium 4s and replacing them with the low-cost Celeron processor. The 2nd reason is because the 3.06GHz Pentium 4 has rather steep power requirements, which cannot be guaranteed by older motherboard designs that weren’t supposed to support >2.4GHz CPUs. Naturally some of them will work, depending on whether how much reserve is built into the motherboard’s power supply, but better be safe than sorry.
Software compatibility is another important factor to consider, both Windows XP Home and Professional will support Hyper-Threading, even though XP Home is not able to support two physical processors in a SMP configuration. Both these operating systems also include optimizations for Hyper-Threading, although it is unclear at this point what these optimizations are exactly. The Linux OS also has support for Hyper-Threading built in, provided a kernel version of 2.4.18 or higher is used.