[jensenoz]

Is it just me or when your running windows xp under bootcamp does windows not load balance the two cores well at all. The best example I have seen of this is when burning a dvd. Pull up performance under task manager and one core is maxed out and the other is running at 25%. Anybody else had this problem and if so is there a solution?

Regards,

JJJ

[mduell]

Is that a problem? Is the DVD burning app well threaded?

[Cold Warrior]

I updated the thread title.

If the CPU loads are not balanced, it's not Boot Camp's fault. The problem would be with Windows XP or the DVD application you're using.

[legacyb4]

IIRC, Windows itself generally has problems with I/O stuff like CD/DVD burning regardless of your hardware.

[mduell]

Originally Posted by legacyb4 

IIRC, Windows itself generally has problems with I/O stuff like CD/DVD burning regardless of your hardware.

WTF? Windows has been burning CDs fine since the OS9 age, when MacOS had a hard time with it (couldn't do anything else on a single proc machine!). DVDs are no different.

[jensenoz]

I used my dvd burning as an example. I have noticed the imbalance in loading between the two cores on basic functions like opening windows, opening Itunes and just day to day tasks. Another good example is if I have itunes playing music and I try and open Outlook my Itunes music will become broken like you would here if you were playing a cd and it hit a scratch.

[silver]

That seems to be a problem with XP, Microsoft is aware of XP not doing a good job with dual core machines.

Google WindowsXP-KB896256-v4-x86-ENU.exe and you'll see what I mean.

Hope that helps.


Cheers

[ghporter]

XP was written in an overwhelmingly single-core world, and it's not at all trivial to change the way it handles loads on multiple cores. The way the Core Duo and Core 2 Duo chips handle multiple threads may be just different enough from the way previous processors did it to make for a mismatch between the OS's control and the processors' structures-which leads to something like "horrible load balancing problems." Again, it has NOTHING to do with Boot Camp. When you boot into XP on your Mac, you're booting into XP. There are what the PC world would call "chipset drivers" provided by Apple, but they are probably less of an impact than the OS being effective in handling the threads and efficiently and effectively ASSIGNING them to cores.

[mduell]

Originally Posted by jensenoz 

I used my dvd burning as an example. I have noticed the imbalance in loading between the two cores on basic functions like opening windows, opening Itunes and just day to day tasks. Another good example is if I have itunes playing music and I try and open Outlook my Itunes music will become broken like you would here if you were playing a cd and it hit a scratch.

That sounds more like a disk access issue while Outlook sucks up it's giant PST and iTunes isn't doing enough caching.

Originally Posted by ghporter 

XP was written in an overwhelmingly single-core world, and it's not at all trivial to change the way it handles loads on multiple cores.

XP (and 2000/NT4 from which it is derived) were written with multiple cores in mind; the XP licensing model even reflects this.

I suspect the OP's DVD burning app is not well threaded, since that's the "best" example he's seen. Other more well threaded apps would be poorer examples of core load imbalance.

[ghporter]

Originally Posted by mduell 

XP (and 2000/NT4 from which it is derived) were written with multiple cores in mind; the XP licensing model even reflects this.

Absolutely true, but have the HALs been kept up to date with newer processors? At the time all three of these OSs came out, multiple cores were only available on server platforms. If the current batch of HALs has kept up, fine, but I doubt MS has put in the effort to do this, considering the fact that they were going to call XP "obsolescent" until very recently.

Originally Posted by mduell 

I suspect the OP's DVD burning app is not well threaded, since that's the "best" example he's seen. Other more well threaded apps would be poorer examples of core load imbalance.

This is the most likely scenario, no doubt about it. It doesn't matter what the OS does if the app isn't properly built.

[mduell]

Originally Posted by ghporter 

Absolutely true, but have the HALs been kept up to date with newer processors? At the time all three of these OSs came out, multiple cores were only available on server platforms.

Dual processor workstations have been on the market for ages; no different than a dual core workstation from a thread balancing perspective. If anything multiple cores is easier than multiple processors because you don't have to deal with the possibility of things like NUMA.