It seems when parallels is starting or doing other intensive work it hogs all the OS X processing power. For example if, I resume a Windows 2000 session, and while the status bar is showing I can't do anything else on OS X (even the dock icons don't animate). This is really annoying. Virtual PC, which I used before would go down in priority so it was only running at 50% if it was in the background (and would stop using any processor power if docked). Can Parallels be setup to do the same? In the startup scenario described above, I typically want to start the session and then continue working in other OS X apps until the windows session is ready. Similarly when I switch to an OS X app I don't want parallels eating up my processor resources even if I am doing processor intensive work in Windows.
How much memory do you have? I have 2G and while starting up eats 1 cpu, the other is available and still responds quickly on the OSX side. If you either have a single proc mini or only have 512M or 1G RAM, then I'd say those are the likely causes.
I'm finding that reducing how much memory I give parallels helps performance. I have a 1 gig MBP and I was giving my parallels machine 512 meg. I use parallels for some specific tasks in windows. Basically Lotus Notes development. What I did was bring up the task manager and see how much memory was really being used when I was running everything I needed. I then reduced my memory usage in parallels to this + 50meg. A machine with 256meg seems to be all I need. I now notice that switching in and out of parallels is much faster and suspending the virtual machines is also faster. I know I read somewhere that more memory the better but in my experience this is not true. I also have tons of tools I like to run under windows but on my parallels machine I have limited this to the bare essentially. I try to keep my parallels machine very focused to the task at hand.
Increasing memory on the Mac side helps, decreasing memory requirement on your VM side seem to help too if you only have 1G of memory. I have a Mac Mini with 2G running Parallels/XP with memory set at 512... and a Macbook with 1G running more or less the same Parallels/XP config with XP set at 256MB. Whilst on the whole I cannot complain about either performance-wise now, this is only after tweaking. I have definitely noticed that the Macbook (with a little more CPU but half the memory) is more inclined towards performance loss. On my 1G Macbook, I was initially using my Parallels/XP setup using 512MB (copied directly from my MacMini machine) but too often found that the rainbow animated icon went into overdrive. This reduced *dramatically* after setting the XP memory to 256. However my performance is still better on my MacMini with 2G of memory... Max out your Mac memory if you can... this is *best* solution for getting the best out of Parallels... otherwise I would suggest 256MB for XP if you only have a 1G machine..
vamp07 & hairy are totally correct. Reduce your Parallels memory to what is absolutely needed and no more. Allocating more memory than your need for your workload is counter productive. Nothing will beat installing more RAM.
Well I have 1GB RAM and have set Parallels to use 196MB for the hosted machine (I have an old 1GHZ laptop with 196RAM running windows 2000 which is the same thing I want to emulate and have been using under virtual PC. Thus I should have plenty of RAM for what I am doing, and the windows stuff inside parallels runs fine. However the problem I am seeing is that when parallels needs processing/disk power it hogs everything even when it is running in the background. The minute windows no longer needs power everything works fine. Thus I guess my complaint/question is more about having parallels relinquish resources when in the background like VPC did
Thanks all, I don't know if its the new beta, or the preference of physical memory that Parallels should use (as opposed to VM memory size) but the problem is fixed I reduced the physical memory that Parallels has access to from th default 600 something down to 312 and it works fine now. Wierd that I needed 312 since the VM is only asking for 196 but it works and I am happy!
I've got my set for 384 (Parallels Desktop --> Preferences --> Memory) and have my Virtual Machine memory for the guest set to 256. The diffence between the two values is the overhead for Parallels. So, your 312 / 196 seems about right. The performance will improve on the OS X side because now OS X has more memory available and won't be paging memory to disk.
