virtualbox.org

Hello,
I've moved to a new PC running Windows 10 Home as the host with an existing Windows XP guest on the latest version 5 of VB plus associated guest additions. Thanks to the great advice I got here, move was absolutely painless. My current XP guest is set to 4 GB of ram as my previous Windows 8.1 PC only had 8 GB in total. The new Windows 10 PC has 16 GB, so I'm thinking about increasing the setting on the XP guest to 8 GB of ram (XP Home max ram is 8 GB I think). By increasing the RAM in the guest, what positive impacts on performance might I expect and am I likely to trigger an XP validation event? Thank you!
OmaSteak

I don't think you will be re-activated, and I don't think you will suffer for performance. But you may (probably will) not get the full 8GB in the guest. Vast majority of XP installs were 32 bit, and that limited the maximum memory address space to 4GB. If you have that rare beast XP-64-bit, you can use all 8GB. But you'd have to use a program or six in the guest that would use up all that memory. Most of the time it would probably sit idle.

Nice thing is you are free to try it and see what happens. Roll it up, see what happens. Roll it down again if you don't like it.

Since I'm running 32 bit XP, curiosity about increasing ram is moot. Thanks for the speedy response!
OmaSteak

I don't know if this is a coincidence or not, but I increased the ram in my XP guest from 2 to 4 MB using the slider in the setting menu. When I went to boot up the guest this AM, I got the AMD-V not enabled error and the guest failed to start. When I reduced the RAM back to original 2 MB, guest booted up as usual. I did not change anything on the Windows 10 Home host. Since the guest ran fine yesterday, I was really surprised this AM at the unexpected error.
OmaSteak

It's not a concidence. RAM >= 4GB makes it a 64bit VM, requiring VT-x or AMD-v.

Thanks! I hadn't noticed that the "Additional Features Status" icon was grayed out in VB. Went into BIOS and enabled virtualization and VB icon shows AMD-V is active. Guess it's part of getting new PC set-up properly for my requirements. The speedy support here is amazing and greatly appreciated.
OmaSteak