ORIGINAL: tmrpro

I'm still curious if Windows and non-hyperthreaded CPUs allow to MultiTask multiple single threaded processes without HyperThreading?

Windows uses a mix of cooperative and preemptive multitasking.

Basically, windows sends messages to each running application from time to time, the application responds to the message. If an application is taking too much time, Windows can pre-empt it's timeslice and move on. This works great for well-behaved applications, the problem is the badly behaved apps (read: poorly written).

One example of a poorly written app that will dominate your system is the typical CD-ROM device driver.

Hyperthreading changes the way this is accomplished, even the worst behaved app will still get time taken away when required under hyperthreading. This is why hyperthreading improves the perceived responsiveness of the system... the UI almost always gets some attention.

As someone else pointed out, sometimes this will result in a small net loss of overall performance, but more often it results in improvements.

ORIGINAL: tmrpro
I'm still curious if Windows and non-hyperthreaded CPUs allow to MultiTask multiple single threaded processes without HyperThreading?

Yes.

I can't see why anyone would want to turn HT off unless your Motherboard or CPU doesn't support it. Nearly every P4 motherboard Made from the last 6 months uses HT. I recently installed a fresh OS of XP Pro and unfortunatly I didn't get HT to show up on the install and my system ran like a snail compared to when I used HT on XP Home. I reinstalled and got HT to work and it ran basically twice as fast in most things especially with sound and video.

I also find that Sonar 3 will only use one CPU from using Task Manager and right clicking sonar - "Set Affinity". I usualy click to use both CPUs and also set Prioriy to "High" or "Realtime" and this is all done in Task Manager and you can also see if you have two CPU's running easily here as well in the "Performance" Window but you may need to turn on "View > CPU History > "One Graph Per CPU"

I think that's and old article made before the 3.1 (and 3.1.1) update....