Ondrej wrote:Hi, I have the same problem. My host runs Windows XP on Intel Dual Core CPU, but I am not able to increase number of virtual CPUs from 1 to 2. In some discussions I found an information, that host must support HW virtualization in order the VBOX be able to present more than one CPU. But I didn’t find that information in an official VBox documentation (e.g. I would expect it in User Manual – chapter 188.8.131.52 ). In my guest configuration is VT-x/AMD-V enabled by default, but my HW doesn't support HW virtualization. Is that the reason of my problem?
I have VT-x/AMD-V checked and disabled (can't turn it off). Not sure what it means.
Is it grayed out but checked? Mine is like that and if you read the manual it will tell you that is default setting now in Virtual Box because so many CPUs now support Hardware virtualization. But if it is grayed out that means that Virtual Box thinks your CPU doesn't have Hardware virtualization.
I have a CPU that Dell promised had Hardware virtualization but it doesn't so I have to use software virtualization only. I read all around the net that VirtualBox would use both my CPUs even though I don't have hardware virtualization. So, that is a main reason I got VirtualBox. I just made my first guest and kept trying and trying to move that slider so it would use both CPUs. It does say this in 1.2 of the User Manual:
"VirtualBox's 64-bit guest support (added with version 2.0) and multiprocessing (SMP, added with version 3.0) both require hardware virtualization to be enabled. (This is not much of a limitation since the vast majority of today's 64-bit and multicore CPUs ship with hardware virtualization anyway; the exceptions to this rule are e.g. older Intel Celeron and AMD Opteron CPUs.)"
I don't know why it says the exception to the rule is older Intel Celeron. I have an Intel Pentium 4 670 processor at 3.8GhZ with hyperthreading and NCQ. That is no celeron! This computer tests faster than many dual core machines that are much, much newer. Dell's mistake in assuring me this processor had hardware virtualization was probably because they were thinking of the 671 that does have it. Intel's site at the time was confusing as it appeared that the 670 had it also. I am disappointed as I was hoping to see both processors in guests made with VirtualBox.