what is ur RAM?? get good quality DDR2-1066 RAM if u wanna overclock ur processor.. Also, whats ur HDD?? There are a lot of really fast new HDDs on the market.. Like Samsung spinpoint F1 or the Seagate 7200.11 series (with 32mb cache).. Or for even better performance, Velociraptor!!
Thats a good build
Also for RAM i say go for a DDR2 800 RAM with 4-4-4-x or lower timings because the difference between DDR2 800 and 1066 isn't much and
DDR2 800 OCs very good too
also for HDD, go for a 7200RPM HDD with 16MB or more cache
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XPS M1730,IntelCore2Duo T9300@2.5GHZ,2x8800MGTX in SLI,4GB DDR2 667 RAM,DUAL 250GB 7200 RPM,VISTA HP with SP1,17" with 1920x1200 resolution