MBP & Vista (with Parallels)

I have a MBP with a Core 2 Duo 2.16 running Windows XP under Parallels.

I've noticed that the MBP runs hotter under XP than it does under OS X. Not sure why this is unless it's just that the power management for OS X is confused about the CPU resources being used by WinXP. Anyhow, I've experienced this first hand and it is somewhat disconcerting. However, as a Windows developer, I MUST run Windows and considering a purchase of a NEW MBP with the new Santa Rosa chipset. I also now need to work in Vista AND XP so I need to setup two virtual machines in Parallels. I anticipate spending more time in Vista and will probably only run XP for apps that don't run properly in Vista. (Yep, there are more than I thought. Take Ulead Photo Explorer. I've been using this since version 2.0 and they are up to 8.6 and it still doesn't work in Vista.)

My question is, does the Santa Rosa MBP exhibit these same thermal characteristics when running Windows in Parallels? How about if you run Vista in Bootcamp?

 

A given temperature in your machine results from many factors both internal and external. If you keep your ambient room temperature and circulation, and internal components constant, the only change is from the load your are putting on components and the level your cooling system is running at.

Under OS X, more system load will increase cooling system in an absolute attempt to keep internal temperatures below a maximum, and a general attemlt to minimize internal temps - moderated by a desire to keep cooling fan noise down.

If you look at your Parallels CPU load, you should see a VM sitting idle, consuming about 20% of one CPU constantly - this is a reasonable load and will cause the fan to speed up a bit and the temps to rise a bit. Try this same experiment under Vista (at least the final beta version) and your base CPU load will about double to 40% of one processor with an "idle" system. The Vista part may have improved with Parallels tuning for Vista more but in general you will notice more load in Vista because there is a lot more overhead. This will cause your fan to run faster and CPU temps to increase.

The flavor of the machine you run on won't change these generalities much but the specifics might change a bit.

 

Well, running a VM will have some extra CPU overhead associated with it as Parallels has to manage an essentially whole other computer virtually.

Unless Apple has finally included support for it, running native through Boot Camp won't have all the power management techniques either implememted at all or fully (at least for Napa based MBP's) so it would most likely run a bit warm like when using Parallels.

I'm not sure how warm a SR based MBP would be when compared to the Napa platform, but I would assume it would be similar when using Parallels. From what I've gathered, power management support running Windows natively on SR seems to be greatly improved (possibly fully implemented).