as the title says, i'm running windows 7 professional (32 bit) with an XP mode. i currently have 3gb memory on 2 sticks (2 slots only on the motherboard).

i have 512mb memory allocated to the xp mode. i'm thinking of increasing it since i sometimes have problems with "low memory" messages in the xp (especially when updating avg which i run there).

however, i can buy two new memory sticks to give me 4gb of memory.

my question is this:

since 7 can only see 3gb of memory, if i increase the memory to 4gb and i set xp to see 1g, will they effectively be using their "own" memory or will they still be competing for the same 3gb?

thanks in advance.