I was getting similar results on my bootcamp partition, and during startup of Parallels the Mac side was essentially hung, with long delays booting Win XP SP2. Both Parallels and all Mac applications ran slowly as long as Parallels was active. That was with half of my 2GB of RAM assigned to Parallels, on a Core 1 Duo 2 GHz Macbook. After reading some threads from Linux users I reduced the memory allocation for Parallels to 512 MB, and that made a huge improvement in both Mac and Windows performance. Chances are that Parallels was taking too much virtual memory from MacOS, and ended up causing paging on the Mac side. Now my CPU use is about 15% of one CPU for an idle boot camp Windows partition, dropping to 7% if I pause the VM. That is similar to the CPU use from a typical Mac program that has windows open but is idle. Parallels often uses over 100% of one CPU when there is real work being done in Windows, but that's to be expected.
CPU usage I had 70-80% idle CPU until disabling USB and other unnecessary (and unused) "features." Now it idles around 30-35%. Better but still unacceptable. I'm also amazed that this problem still persists after a year, and anxiously awaiting VMware fusion. Maybe having some real competition will make them more responsive to fixing these sorts of bugs.
You can try the VMWare beta. It works well for me, low idle CPU. I've recently had an unresolved problem where I couldn't install Vista nor Ubuntu using Parallels to an NFS mounted drive. No problem with VMWare.
Anybody has an update on the excessive processor usage problem? Ironically, it more than double for me after the beta - problems are supposed to go the other way. I've e-mailed support - I've paid the registration fee - but have yet to hear from them.
Disable USB, don't use coherence .. enjoy the magic of almost reasonable CPU utilization. If you can't disable USB, nothing you can do.
I don't know why, but I don't have a 30% idle on any of the machines I manage... They even use coherence.
Parallels vs. VMware Fusion I ran a few tests comparing the performance of Parallels 3188 to VMware Fusion Beta 3, which finally allows you to disable debugging information. The results indicate that Parallels still beats the competition, and that the "idle CPU" usage problem happens within VMware as well. VMware's support for multiple cores is promising, but if Parallels comes out with this in their next release (and does it well), I suspect they will maintain the lead for some time.
Bump... It seems there are some Parallels support staff browsing this forum and answering questions after a long absence. Hopefully they will start to take note of this longstanding issue. Parallels, if you are reading this, I have another data point for you. I installed RHEL3 which runs a 2.4 series kernel and it doesn't seem to exhibit this CPU sucking behaviour. andy
andy (in case you're interested) almost everyone in the team (not only support, but qa and developers as well) recieves every message on the forum through the RSS notification. please, be sure that we're aware of most problems that are being discussed here. and we're constantly working to fix most notable ones.
tacit_one, well, that is good to know. Perhaps when you are all working on it you can drop us a line, like you do a lot of the time, but how about whenever you start working on it. It gives us a better sense of security.
You've certainly been sitting on this a long time. I've lost count of the number of times I've reported this problem in the forum, via email to support@, via email to beta@. This is the first time in almost 5 months of use that anybody from Parallels has replied to say they are aware of the problem. The only response I ever got was "we'll get back to you in 3 days", but there was no further contact after that. I'm a registered user and this is a critical issue for me, it literally halves my battery life. Any ETA on when we might see some improvement? Much of this frustration could be solved by a one line reply acknowledging the issue, this is all the more infuriating since you admit that the whole team sees these problem reports yet nobody (until now) has dropped in to confirm it's being investigated. andy
Fix for high CPU of idle Linux guest I can't speak for Windows, but there is a fix for high (20%+) CPU when a Linux guest is idle. This seems to be related to the HZ setting in the Linux kernel which is normally set to 1000. For some reason this high frequency causes extra grief for VM software, at least for both Parallels and VMware. I changed this setting to 100 in my Linux guest and saw the CPU usage drop to under 5%. Here is a good thread on the problem (CentOS forums): http://bugs.centos.org/view.php?id=1680 If like me, you're too lazy to recompile your kernel, there are also (patched) third-party kernel RPMs available at (be aware that this is risky, though; it's safer to recompile): http://vmware.xaox.net/centos/4/
parallels is too hot Hi, I started using build 3188 about two weeks ago. I would like to report that the CPU issue is the only point that refrains me from using Parallels full time (I boot from bootcamp whenever I need performance or longuest windows battery life). I'm running a 2Gb 2 Ghz CoreDuo MacBook, winXP on bootcamp, with circa 7-10% CPU with VM in pause and 30-50% CPU with VM running and idle. For my usage, battery life is circa 3:50 h without VM running, around 2:10 h if I remember to pause the VM - and that is with a 2 month old computer - less with full win use. Besides, once the fan runs I cannot keep the computer on my lap anymore, and that defeats the purpose of a laptop. I would agree with other posts here that this issue is "hotter" than coherence or pure performance, which is already pretty good. J.
I bet that the thing you really should worry about is your battery life time (not cpu usage itself wich is not the only thing that harms it). We're aware of the mobile VM use-case and we will try to make modifications to our software in order make battery life as long as possible. But i can't give you exact timings, the only thing i can say that we're aware of the problem and have this task scheduled.
You can greatly reduce CPU usage by going to your VM settings and disabling USB support if you don't need to use USB devices under Windows and sound input support if you don't need to record sound from a microphone in XP. Also, remember to disable any anti-virus/spyware/adware that you have installed on your PC as they can slow down your system more than anything else. You probably use MacOS to browse the web and check your emails so the probability of getting some nasty stuff on Windows is fairly low and your VM is sandboxed anyway. On my MacBook C2D 2GHz with Windows XP SP2, parallels in Coherence mode uses 9% of CPU when windows is idle and 2% when the Virtual Machine is paused (that's with USB enabled but any connected USB device disabled from Parallels). Quite frankly, I'm very happy with Parallels at the moment including its CPU usage.
half as hot Hi, To vioccc : compliments, I played around over the weekend and figured out I can live with my only USB device through the Mac, altogether I stand now around 5% paused and 15% idle with USB support off. Thank you. As for battery use, I will post more feedback once I measure the improvement (in theory it should !). Maybe this finetuning work should be suggested in the manual in a more straightforward way. J.
3.0 Vista CPU Utilization What is everyone getting for their CPU utilization? I am just idle with Vista and Parallels is at 50%! Is all the extra eye candy in Vista causing this? Because in XP my CPU utilization is usually less then 10%. Thanks.
Parallels 3.0 using 80% CPU power One thing I liked about the latest version of 2.5 was it did not take up all the CPU and the fan did not on on all the time. I just upgraded an Parallels 3.0 is using up to 80% without doing anything more than I did in 2.5. is this normal? I am running XP pro on Mac Book Pro, mas os 10.4.9 Is anyone else having this problem? -Cheers
After upgrading to PD 3.0, I'm not seeing any changes between the CPU utilization of the host OS when there is no guest CPU utilization. I know this has been a sore subject for a long time, and we've been promised that it was being worked on and would be fixed. My guest XP machine has no CPU utilization, but the host is running at 45-50% utilization all the time. Was the host CPU utilization supposed to be fixed in 3.0? MacBook Pro Core2Duo 2.16Ghz 3GB Ram Guest XP with 1GB RAM.