Why CPU Usage only 40% max?

I am using Vaio SZ core cuo 1.83 GHz.
When running some heavy application (convert or encrypt large video files) and cheking Task manager I see CPU Usage (under Performnce tab) reachs 40% at max. I wonder why the CPU Usage indicator could not increase up to higher (say 70-80%)? Any help?
Thanks

 

Probably because whatever program you're running is not multi-threaded. Software needs to be written to use multiple processors. If it isn't then the OS will assign the process to one of the CPU's, leaving the other idle for you do what you will. Like surf, write a document, whatever. So you still benefit, sort of.

Usually video encoders are optimized this way. For instance fire up the latest Divx and encode some video, you'll see both CPU's working for sure.

 

Thank 4 ur reply. But in my case, both CPU are running, but each CPU reachs 40% at max only, when running heavy programs. Why not higher?

 

I'd be happy if I were you.

 

I'm not sure why it's maxing at 40% - if the program demands all the processing power it can get, it should max at 50%. So the program probably only requests about 80% of one core's power when running. Another bottleneck - such as the hard drive - could explain that.

As to Task Manager showing each core at 40% rather than one at 80% and one at 0%, I don't know. This has never made sense to me. Seems like a single-threaded application that demands 100% CPU should result in 100% on one core and 0% on the other.

 

do you have your power settings set to max battery instead of max performance...thats the only thing i could think of...but even then, it should reach 100% just at a lower clock rate...this is weird...run a copy of benchmarking software and see if you still see this.

 

Yeah, I'm thinking along the same lines of nizzy, but that should only be changing the multiplier. Do you have any stock power software or notebook hardware control software installed? Maybe that is changing the load.

I have a suggestion though: http://www.wprime.net/download.html Download that and run it. That should stress both cores 100%. If it is still at 40%, write back because that program is supposed to max out both cores.

 

I'm thinking that your CPU simply isn't the bottleneck. What is your hard disk usage like using this program?