XP 64bit Memory Increase

[THT]

I currently have 2 x 1GB Sticks of Ram in my machine.

Looking for an upgrade and have around £ 50 to spend.

First of all, Will Xp64 go over the 3gb limit that Xp32 has?
Should i then
1) buy another 2x2gb and have 6gb
2) should I sell the old sticks and get the 2x2gb and have 4gb
3) buy another 2x1gb and have 4gb?

Thanks

 

[THT]

so 2x2gb equalling 4gb, will give me better performance than 6gb total?

 

[THT]

but whats the point in hanging on to them? and do what with them?

Any of the benchmark tools give me an accurrate idea of which is better?