Is Wine Necessary for steam games to run at full speed? topic

Is wine necessary as I plan to play DOTA 2 and Left 4 Dead 2 on my PC,
(I am dual booting UBUNTU 12.04 LTS with Windows XP SP3 32 bit)

My system specifications are as follows
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Amd Athlon II X2 260 3.2 GHZ
Asus M4N68-T LE-V2
4GB DDR III 1333MHZ GSKILL RAM
ASUS HD7750 1GD5 V2
1 TB WD PURPLE
500 GB WD GREEN
(C: WINDOWS XPSP3 250 GB , E: UBUNTU 25GB '/', 16 GB 'SWAP', 226GB '/home' F:463 GB) FROM 1TB
(D: 146 GB BAD SECTORS G: 146 GB GOOD, H: 172GB GOOD) FROM 500 GB HDD
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