virtualbox on resources

1.
I read that virtualbox handles resources more efficiently. How much more efficiently

I have used VMware before and had to specify the amount of ram to allocate to the VM guest upon creation. Is it the same with Virtualbox??

my host system has 1gig of ram & 3000+ amd64 on a winXP32

Lately I was thinking about re-installing VMware on my comp... basically I want to have 2 guest OS windows open at the same time... They might not be doing much but from time to time I may run/install a prog or 2 {the same I will do with my laptop, since I not only want to start xp clean and gradually re-install all my aps since its allot to do in one shot, + give vista a try, +do the same for my laptops}... I intended on allocating 512k to each VM... Would that necesarily mean my system would crash or be terribly unusable with VMware even though those systems wouldn't be utilizing full resources actually allocated to them??

Would my system be crippled?? In the same circumstance would Virtualbox do a better job/ crash or render my comp undesireable for any activity??


2.
None the less I intend to buy my host more memory and just might get either a dual core or dual processor. If I'm not mistaken if I should upgrade my machine with both memory & processor isn't VMware be more suitable to utilize either dual core or dual processors? I utilization of the extra processing power would be better utilized in VMware since I remember reading processor compatability in their whitepapers for their different products... I'm still unsure asto whether the workstation version would have the capability to harness the power of more then one core/processor but am assuming so, and also assuming virtualbox wouldn't do as well in the area since its a free tool... can anyone comment?

 

Thanks for clearing that up... I'm going to have to definitely upgrade ram first or just load 1 vm at a time, for now.

btw
virtualbox doesn't support smp

http://forums.virtualbox.org/viewtopic.php?t=2405&highlight=dualcore

VM workstation 5.5 does

http://www.vmware.com/support/ws55/doc/releasenotes_ws55.html

 

with VMware i thought you could change the amount of RAM allocated after creating the image, you just edit a file i think.

if you're upgrading your hardware i think you should make sure your motherboard can cope with the new stuff.

qemu is ok for trying out things quickly, i made a right-click option to run *.iso in qemu and it works ok for me