Sh5 with xp??

Will Sh5 run on xp? or is Vista as far back as it will go. I ask because I want to run it on my Mac but I was going to put windows onto it with bootcamp instead of fiddling with things like wine and what not. I wanted to buy the newest I could get without getting Vista because I hated vista, so I figured XP would be a safe bet to be able to still run newer games, that and cheaper to buy as well.

I believe I can run it smoothly too, I have a 2011 13" pro with these specs:

-2.4GHz dual-core Intel Core i5 processor with 3MB shared L3 cache
-Intel HD Graphics 3000 with 384MB of DDR3 SDRAM shared with main memory
-500GB Serial ATA; 5400 rpm
-8x SuperDrive (DVD±R DL/DVD±RW/CD-RW)


Now in an earlier thread, Pilot_67 said he got 3 and 4 running smoothly on a 2011 11" Macbook Air. (1.8ghz 256gb hd with 4gb RAM).


But he had to turn down the graphics to all low on V for it to run smooth. I checked and saw his graphics card (according to the site) was the same as mine, and the only thing I could do is upgrade my ram from 4 to 8gb, the other part of that question, if anyone cares to answer is, could that 8gb of RAM make the difference at all about how high I can turn the graphics without losing game changing performance?