Computer HT question

[kamikaze82 0]

Is HT(hyper-threading) all what it's cracked up to be?

I've been watching my CPU usage under task manager and noticed that when I ran disk cleanup performance would show 70 to 90 percent total cpu. I checked processes and disk cleanup was between 40-60% mcshield 5-14% but my system idle was around 50% and my cleanup was sluggish.

My question is why is my cleanup slow but my idle is taking up half the processor? From what I understand is idle has a low priority so why wouldn't it slow and send the rest to diskcleanup?

CPU: P4 3.0ghz HT enabled (for now)

¡YA BASTA!

[Loonix 0]

CPU is only one of several things that determines performance. In this case, the bottleneck is probably your harddisk.

[kamikaze82 0]

i hope it's the disk cause i have a spare. but all those files i would have to transfer

how can i find out without opening everything up and changing all of it?

¡YA BASTA!

[dorbie 0]

With hyperthreading when your cleanup process is waiting on the disk it is probably scheduling the idle process in because there is no penalty for doing so. It is not that te idle process is taking up half the CPU, the problem is that the cleanup process is unable to keep the CPU busy (probably due to disk i/o). It's called the idle process for a reason.

When CPUs run multiple tasks they need to schedue between them. This means that all sorts of executable information like instruction cache program counters and registers may need to be changed.

Hyperthreading duplicates all of that (cache etc can be shared, the real smarts is in the duplication of registers which can be complex on a modern CPU) although there is one CPU core w.r.t. arithmetic units etc. it has duplicate resources and can pretend that it is two CUs. This reduces he overhead of multitasking.

Its a small but significant benefit.

Hyperthreading is now obsolete though. It is obviously much better to have 2 real CPUs than one hyperthreading CPU. Core duo CPUs are a great choice, you won't be disappointed. But there's nothing wrong with your current system, you shouldn't expect disk intensive activity to keep your CPU busy.