Yes Tatty is correct. Best multiplyer for the 930 was 21. I went all the way to 4.58ghz @ 1.4 volts but 20x was boo hiss, lucky to get to 4.4ghz.
My best settings for the 930 were 4.2ghz @ 1.268v with a 200bclk x 21.
everything else was standard voltage except when i had to try and get memory up and going at 2000+mhz.