How much RAM should we give to our virtual machine?

[Helloween]

Hello, i'm using virtualbox to have a program in my real machine to send information to the virtual machine,
i'm experimenting issues with that, after some time the rate of the information flow is delayed, i don't know if this is because of the RAM i use in the virtualbox, can it be?

My computer is pretty old, it's a core 2 duo, 3 GB or RAM, i give 1 GB to the virtual machine...

btw, which is the best way to optimize RAM usage?
i'm thinking about using virtual machines inside virtual machines, so which is the best way to spread 8 GB of RAM if we're thinking in using a real machine>virtual machine> another virtual machine inside the last one?

should we keep it 4 GB in the real machine, 4 GB in the virtual one and then 2 GB in the last one?
what if we use 3>3>2?
or 5>2>1?

thanks

[BillG]

With most virtualization systems, vm within a vm will not run. Even if it does, it is slow and inefficient.

viewtopic.php?f=1&t=20589

[Helloween]

but what if we need it to run programs that don't need much RAM?
i think that 1 GB is a lot for what i need it to do, probably the minimum required would be 250 MB of RAM...
do you know which would be optimal memory distributions for that?