32 or 64 guest

[loukingjr]

I have to agree. I think the problem is people read about some performance difference in a review somewhere and think it must be significant. I believe if you sat someone down in front of a screen and had them use both a 32bit guest and a 64 bit guest they would not be able to tell the difference.

[mpack]

they would not be able to tell the difference.

Except they may notice that one of the OS's was hogging an inordinate amount of RAM before we've even installed any apps. And oh yeah, on one PC none of our existing device drivers will install.

In my comments above I didn't say that VirtualBox had a higher resource overhead for one or the other - it may or may not, but not by enough for me to care. It's the overhead of the OS itself that I notice, especially when I don't really need single apps having access to >4GB flat addressable RAM, which is really the only thing that a 64bit OS can do that a 32bit OS can't.

A large number of FAQ questions on this site are from guys getting VERR_NO_MEMORY errors when they try to run two 64bit OS's (guest and host) on the same hardware. 64bit host and 32bit guest is usually better, 32bit host and guest rarely gets into trouble on modern hardware, in fact it flies.

[loukingjr]

as I first stated there are many factors involved in choosing between a 32bit and 64bit guest and it's not a simple question.

[dimedrol7]

VirtualBox doesn't simulate the CPU, code runs natively on the host processor, at native speeds. The only thing VirtualBox simulates is peripheral hardware: the surrounding PC.

I have Intel CPU (Pentium 4 ht 630) without hardware virtualization.

# cat /proc/cpuinfo | grep flags
flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pebs bts pni dtes64 monitor ds_cpl est cid cx16 xtpr

I planning reinstall Linux on my host. I have 4 Gb ram. I'm going to run Windows xp sp3 32 bit guest. For guest will be allocated not more than 2 Gb ram.
I am not profi. I suppose in my case natively running is not possible, and VBox will simulate cpu for guest.
Tell me please, in my case, does it matter for Windows 32 bit guest performance, what version of Linux (32 or 64 bit) to install on host ?

[mpack]

If your host CPU doesn't have hardware virtualization then you can't run a 64bit VBox guest, making your question somewhat off topic here. To answer briefly: a single core P4 is quite primitive I'm afraid - you should stick to 32bit for both host and guest, assuming you even have an option.

[Palarnik]

At the moment i use a Windows 64 bit host. Now i want to use Virtual Box to run a Linux guest. So my questen is:
Does a 32 or a 64 bit guest have a better performance.

PS: My notebook has 8 GB RAM and i want to use the guest with 4 GB RAM

Thanks for answers.

you have to take 64bit guest, if you want to use more than 3.5GB RAM