id,summary,reporter,owner,description,type,status,component,version,resolution,keywords,cc,guest,host 10790,Ubuntu 12.04 client very Slow inside a Win7 host,hagen,,"It seems others have reported unusually slow performance of a Ubuntu 12.04 client in vbox on a Win7 host, but no clear resolution has been reported yet. I have heard rumors that Ubuntu 12.04 is slow, so I have been sticking with 10.04 LTS. Today, I finally had a chance to install a 32-bit Ubuntu 12.04 desktop in Vbox 4.1.18, and it really was slow. Some suggested this may be related to Unity 3D, so I installed gnome-shell and logged in using Gnome Classic (No Effects) but the performance wasn't much better. I tried it with VT-x off and then VT-x on without nested paging, there is virtually no difference. The boot was slow and the overall performance just seemed sluggish. Then I decided to make a relatively simple measurement of the display performance. I have a program that I ran in gnome-terminal. When it runs, the program writes 100,000 lines to standard output, or output can be redirected into a file. Obviously, writing to the terminal will be slower. In the Ubuntu 10.04 client, the program took about 60 seconds, while it took 20 seconds without output. But in the Ubuntu 12.04 client (with Guest Additions that came with Vbox 4.18 installed), it took almost 5 minutes with output to the terminal but again 20 seconds without output. If I go to the System Settings in Ubuntu 12.04 and activate their ""Oracle VM Virtualbox Guest Additions for Linux Module"" under Hardware/Additional Drivers, the time with output decreased to about 4 minutes. It seems they were two different versions of the Guest Additions and they gave different performance. But both were substantially slower than Ubuntu 10.04. CPU usage when the program was running was about the same in both 10.04 and 12.04: 35-40% Xorg, 15-20% gnome-terminal, and the rest is a.out. I checked the properties of gnome-terminal in both Ubuntu's to make sure they were the same -- neither had transparency and they had the same scroll buffer size. (If I could access older versions of the Guest Additions, I would be interested to find out if any of them perform substantially differently.) Some claimed they observed better performance with a 12.04 client in VMPlayer. Though the installation of Ubuntu 12.04 in VMPlayer using the Easy Install method was quite a bit faster than in VirtualBox, the gnome-terminal test result was actually much worse in VMPlayer. As a final experiment, I installed a Ubuntu 12.04 client on a Mac OSX Snow Leopard host. I have absolutely no problem there. Timing from both 10.04 and 12.04 clients are almost exactly the same. The graphical interface also seems a lot more responsive. 12.04 Performance on the Win7 host definitely seem much more sluggish. I don't know if I am missing something obvious or if this is related to Ubuntu 12.04 client issues that other have reported previously. But there is clearly an issue here. Log file attached.",defect,closed,other,VirtualBox 4.1.18,obsolete,,,Linux,Windows