Sudden speed issues

P

pomacoder

Bit poster
Hi everyone!

I'm running an early 2010 MBP (Core2, 17", 8GB ram) and am having a speed issue with Parallels 7.0.15054 with ANY of my virtual machines:

Both times I have fresh installed my mac, I have had the same result: Install Lion, update, create and install Win 7 bootcamp, update windows, install parallels on Lion, create VM with bootcamp, install tools, begin using Windows + Mac. The methods I use for this installation are all standard and when I am 'done' Windows boots and runs great in both bootcamp and parallels!

However, both times parallels has suddenly gone from running well to very slow and stuttery.

I originally attributed it to me messing with the networking, as the first time I was showing off and installing a Linux VM at the same time. I bridged the network connections for both VM's to my ethernet card and Parallels became slow. Somehow I also had a broken ethernet cable that was the cause for a self assigned network issue on my Mac (and consequently the VM and bootcamp as well) that I had at the same time, but replacing that did not change the speed issue.

So I clean-reinstalled again. Fresh Lion, fresh bootcamp windows 7, fresh parallels. And it was working great again! But now it's not. This time it became slow after the update to 10.7.3 (I only had 10.7.2 on the previous install), though I do not know whether that is the underlying reason.

Booting into bootcamp runs just fine, but working strictly in windows or strictly in OSX isn't really an option for me. OSX doesn't even seem to be phased by Parallels running and that's with 4GB attributed to the VM.

I also mentioned multiple virtual machines having the same problem in my opening sentence, this is quite true and the reason I'm asking for help with Parallels. I would have thought that it was just the bootcamp/parallels combo, but any of my VM's (win7, winxp, linux) run incredibly slow and stutter.

I must also mention that I am running dual hard drives on this model, a solid state drive in the original drive slot and the original HD in a Superdrive to HD adapter in the superdrive slot. I would not think that this makes a difference, but this is the only non-standard modification to this laptop. Both windows and mac are running off the SSD while the HD is used for scratch and Timemachine backups.

Puzzled and confused,

pomacoder
 
Probably the result of paging.

How much physical RAM do you have on the machine?
Remember that RAM has to be shared between host (OSX) and guest (Windows), so, just as an example, if you give 2 GB to Windows and have a total of 4 GB installed, OSX is left with only 2 GB which, depending on the apps running on OSX it might make OSX page.

Also, if you have more than one VM running at the same time you have to subtract the RAM assigned to all VMs running from the physical RAM available which wil leave even less RAM for OSX.
For instance:
4 GB total RAM
Windows VM: 2 GB Virtual RAM
Linux VM: 1 GB Virtual RAM
When run simultaneously, it will leave only 1 GB for OS X (and apps running on OSX), in this scenario the computer (all operations) will likely run very slowly due to constant paging.

When you get that slowness again check the Activity Monitor.app for memory usage and see how much free RAM do you have available.
 
Last edited by a moderator:
Thanks for the replay!

That's the thing, though, it doesn't slow the mac down at all. I can open and run anything at the same time and Lion acts like it isn't even aware of the VM running (like it normally should).

I'm sorry, but I did try to make it clear that have 8GB of ram, 4 of which are dedicated to the VM. And yes, two VM's at the same time will cause a slow down due to resource use (ram, CPU, etc), but the bootcamp VM acts like this anyway I slice it (accept for if I natively boot to it).

On a happier note, I did 'fix' the problem by uninstalling Parallels, rebooting and installing a previous build. I will only be convinced, though, if it remains so. I'll post back in a couple of days.

pomacoder
 
Semi-Solution

Update:

Uninstalling Parallels, restarting and Reinstalling Parallels (any version of 7 up to the current (7.0.15054.722853)), then rebooting solves the problem.

Unfortunately, the problem will reoccur after several VM reboots and/or a few boots into bootcamp (haven't exactly determined the culprit), requiring a reinstall, which instantly solves the problem. I am avoiding this as much as possible by not rebooting either OS.

The symptoms that can easily be determined on the Mac side are:

- No noticeable OSX slowdown, but
- Activity Monitor shows 100% cpu usage on one core, even with windows idle (normally, even in coherence, this value does not exceed 5%-10% at idle).
- System Memory has about 4GB in the 'Free' section with a smaller value in the 'Wired' section, between 2 and 3 GB (normally the 'Free' section has ~100 MB free with ~6 GB in the 'Wired' section with the VM running)
- And of course, Windows itself is very jittery and slow, unusable (normally (not sure if this is the right term anymore) it runs smoothly in the VM with only the expected slowdowns from coherence window moving and view mode changes)

I'm going to see how long I can go without restarting before this shows up again, but if anyone knows a suggestion I'd be grateful. Just looking at Activity Monitor, I'd have to agree with Specimen that it is OSX paging of some kind. I would guess that, for some reason, Lion isn't giving Parallels the full requested memory space, forcing it to page data back and forth.

Cheers,

pomacoder
 
Hi,
I have exactly the same issue. I have an SSD with the system and VM on it and the former HD for backup. Since I installed the SSD, my VM starts VERY slowly and runs VERY slowly too. I wait that it loads completely (windows xp), i do not enter a session but click on stop the system and then I launch the VM again. The second launch is always good and it works with normal speed. Still do not know why, but this is really boring...
B/R
Emmanuel.
 
Same problem

I have an iMac with an as manufactured deployed SSD and hard drive. I'm using the SSD for the OS and Windows VM using Parallels7 with Mac OSX Mountain Lion.

My Windows 7 VM has suddenly become very slow. I tried installing the VM again, it quickly got really slow again. I have over 2Gb RAM free and the dreaded 'prl_vm_app' stays pegged at 100% cpu.
 
Same problem here. Parallels 8 running Windows 7 64-bit. 8 GB internal memory and a 256 GB harddrive split in two, one partition OS X and one Windows. Windows by itself is running like lightning, it was also performing great in Parallels (using the bootcamp installation as a VM). I have 4 GB assigned to the VM and 2 CPU cores. There is more than enough memory left for OS X, about 2.5 GB Free Memory.

All of a sudden Windows is unworkably slow. At first I thought it was stuck, but it just takes 14 minutes to boot! When clicking something (Internet Explorer, Start Menu, Anything), I can LITERALLY get myself a coffee and still see the windows opening when I return.
 
Sudden speed issues solved for me

Gideon007 on the Fusion forum solved this one for me.
http://communities.vmware.com/post!r...essage=1991832

I had the a major performance problem with the prl_vm_app process pegging the cpu at 100% or more on my iMac using Mountain Lion (though I suspect this issue would affect other versions as well). The Windows Guest OS was not usable it was so slow.

Turns out deactivating the ethernet connection (which I had done earlier when switching it over to WiFi) was the culprit. After reactivating the ethernet connection, everything started to run in normal speed on the Windows VM instead of super slow motion.

This is a common problem to both Parallels and Fusion.

Hope this helps someone as I was going nuts trying to figure out the problem.
 
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