The host in question is a Dell Precision Tower 7210 with CPU: Intel(R) Xeon(R) CPU E5-2620 v3 @ 2.40GHz (2394.51-MHz K8-class CPU) It's 6 cores (12 if hyperthreading is enabled). I have a Windows 7 VM that worked perfectly well on my earlier (4 core) desktop machine; I literally pulled the disk holding all its files from the old desktop and put it in this one. If hyperthreading is enabled the VM is so slow it's totally unusable. It took over 5 minutes for it to boot. The VM would eventually respond to mouse events so it wasn't hung, just slow. With hyperthreading disabled the VM is usable but very slow; the windows 'spinning circle' busy indicator doesn't spin smoothly, it clearly stops & starts. Changing the number of cpus allocated to the VM doesn't make any noticeable difference. It's not restricted to a Windows guest. I booted a Linux install iso to test, and it had the same problem. Currently running 10.3-PRERELEASE #12 r297026, but it's been like this for as long as I've had this desktop machine (since June 2015). I have another desktop machine running the same version of virtualbox and FreeBSD. It has 4 cores, and VMs run just fine. The only difference I see is that when the 4 core machine (a Dell Inspiron I580) kldloads vboxdrv I get the console message: vboxdrv: fAsync=0 offMin=0x218 offMax=0x1c20 While on the 7210 I get: vboxdrv: fAsync=1 offMin=0x3ae80 offMax=0x3ae80 supdrvGipCreate: omni timer not supported, falling back to synchronous mode I do not see the supdrvGipCreate message on the I580.
i would check to make sure all relevant settings are enabled in the bios. and that the bios is up to date. dell likes to hide some settings inside of other settings.
I can confirm this and I confirm this strange behaviour on several different mainboard vendors (ASUS, Fujitsu, Dell) and on several generation of Intel x86 derived silica (SandyBridge, IvyBridge and Haswell, all XEON with >= 6 physical cores). The systems are strange under VBox with either classical MBR boot and UEFI boot (as available). In our case, the guest (Win7 pro 64bit) is responding extremely slow and the mousepointer is jumpy as hell and unusable.
You can try to use CPUSET(1) to start the VMs as explained in: https://lists.freebsd.org/pipermail/freebsd-emulation/2012-November/010209.html On an Intel Core i7-3930K based PC I am starting a Windows 7 VM with the command : # cpuset -l 4-7 VBoxHeadless --comment "Win7;5901" --startvm "Win7;5901"
I recently upgraded to 10.3-STABLE r303336, and I decided to try upgrading virtualbox to the newly committed 5.0.26 at the same time. Hyperthreading is enabled, so FreeBSD reports having 12 cores to play with. It now seems to work fine! My Win7 VM (which hadn't been touched since I filed this bug report back in March) is now perfectly usable. Unless some stability issues show up (it's been running for almost 3 hours now), it looks to me like this ticket can be closed.
VirtualBox 5.0.26 fixed the issue. Closing.