Hyper-threading without the hype
Published: 01 Oct 2002 16:23 BST
Can I plug in a hyper-threaded chip as a replacement for my old Pentium processor on an existing motherboard?
No.
Will I need faster memory if I use hyper-threading?
Hyper-threading does make higher demands of your memory than single threaded execution, because two threads running simultaneously can consume more memory bandwidth than one. In the figures Intel has published to date, it has been using Rambus 1066 memory -- the fastest available. No figures have been published for slower memory systems, such as DDR-RAM, but Intel says the speed-up will be more modest.
Should I buy new software?
Intel says not, but it's hard to square that with its claim of great speed improvements if you do have hyper-threading aware software. Most old software won't do that well on hyper-threaded processors, so you may wish to leave the feature turned off. Intel says that things like background virus scanning, digital media encoding and picture processing will use hyper-threading to best effect, but there are many variables that may affect this. Wait until hyper-threading systems are established and real-world experiences have begun to circulate before deciding this.
The more software that is written to make best use of hyper-threading, the better everything will run. Intel is aggressively promoting the techniques and information necessary for software writers to do this, but there will be an indeterminately long period while everyone gets on board. In particular, look for hyper-threading aware versions of traditionally flaky or hardware-sensitive software, such as device drivers and games.
What operating system support is there?
Linux 2.4 onwards has hyper-threading support. The Microsoft story is more complex. Windows 2000 and NT will regard a hyper-threaded processor as two separate chips, which may or may not be helpful -- performance may be compromised, and software licensed for single-processor systems may complain. XP Professional and Home editions do understand and support hyper-threading, although you need to re-install the operating system if you turn hyper-threading on in the BIOS after installing the operating system. If you subsequently turn hyper-threading off, you'll lose around five to six percent performance until you re-install the operating system in single-processor mode.
Have your say instantly in the Tech Update forum.
Find out what's where in the new Tech Update with our Guided Tour.
Let the editors know what you think in the Mailroom.
Previous
Did you find this article useful?
134 out of 264 people found this useful
Digg
Slashdot
Del.ici.ous
Stumble
Reddit
