How can i Improve performance

Okay so in my sig is my computer stats, my memory timings say 3.0 3 3 7

(the 7 number it says precharge delay :S whatever that means)

could i change anything in those timings to make it better without doing anything to do it

Or is changing those timing things only makes a difference on DDR ram? i have SD 133 double sided chips ram

Also I dont know why i can only overclock so much till it automatically stops it can't got to 1.7 1.68 and thats it, my original vcore is 1.700 i put it at 1.75 now so its stable but max it can go is 1.85 but it still wont go past 1.68GHz.

Umm my motherboard is ECS MSI 423 P4ITA, it also supports RD 800 but when i bought this computer 4 years ago for $1700 I knew nothing about computers and it was either take 128mb of rd800 or 256 sd 133 so i took more ram, didn't know nothing about comps lol. And now 256 mb stick of RD 800 is $130 here in canada and there is no way i'm paying that much for that ram.

PSU rails are 3.3v - 20A, 5v - 30A, 12v- 13A If that info makes any difference.