Opened 8 years ago
Last modified 8 years ago
#15640 new defect
Existing CPU is not supported?
| Reported by: | isgdre | Owned by: | |
|---|---|---|---|
| Component: | other | Version: | VirtualBox 5.0.26 |
| Keywords: | cpu | Cc: | |
| Guest type: | Windows | Host type: | Windows |
Description
I tried to update one of my guess Win 7 to Win 10 and it failed saying it was an unsupported cpu (xeon e5405).
Thing is, Win10 upgrade thinks the CPU is fine on the host computer witch is the same CPU (see screen shoots supplied in zip file with logs)
Attachments (1)
Change History (6)
by , 8 years ago
| Attachment: | VB7DSL90cu14.zip added |
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follow-up: 2 comment:1 by , 8 years ago
comment:2 by , 8 years ago
If I understand you, Your saying my physical cpu doesn't support it so Virtual Box is supplying a virtual one and that Windows 10 and VBox's virtual nested paging are not getting along? Is this something that I should wait to get patched or is it something that can not be done with existing hardware?
follow-up: 4 comment:3 by , 8 years ago
Frank is telling you that your CPU is old and it's missing an important virtualization feature (nested paging) which could make your Windows 10 VM to run unstable. Running a VM without nested paging means a lower performance for the guest OS, in all cases. With your current platform (socket775/771), this feature is not available.
On the other hand, the Windows 10 OS guest (from its perspective) only cares about the missing cmpxchg16b feature, which you can enable by changing the VM OS version from Windows 7 to Windows 10, from the VM settings.
comment:4 by , 8 years ago
Thanks mhanor, But still. Does this mean I need new hardware to make it stable or is the vm's emulation of cmpxchg16b a bug that we just wait for a fix. Specifically that was with reference to the "run unstable" part.
comment:5 by , 8 years ago
Frank said that there are issues when running Windows 10 as a guest, when the host doesn't have the nested paging feature. Getting newer hardware (that has nested paging) could be a solution. What exactly is causing the problem, I don't know. If it's a VirtualBox bug, you may have to wait for a fix, for an undetermined amount of time.


You CPU does not provide nested paging (Intel EPT). The immediate reason that the Windows 10 compatibility check complains is that the cmpxchg16b instruction is not available. This instruction is disabled by default for hosts without nested paging. You could enable it by changing the OS type to "Windows 10 / 64-bit" but there are known issues with Windows 10 on VirtualBox hosts without nested paging -- your guest will most likely run unstable.