I have an AMD Phenom II x4 635 at 2.9 Ghz. Where exactly can i find the external clock speed?
Hello and Welcome! Your External Clock Speed is 200 MHz so your Bus Ratio is 14.5 and rounding gets you 15.
2900 / 200 = 15
So your com.apple.boot.plist should have
<key>Kernel Flags</key> <string>busratio=15</string>
Hope that Helps!