Actually stock clockspeed, but undervolted. Most guys like to overclock on the stock voltage, which you can usually get an extra 10-15% on the newest cores, such as the Athlon64 SanDiego core mine has. Rather than go the overclock route, I undervolted mine, and it astonished me with how far under voltage it could go and still pass Prime95 testing as totally stable without errors. I'd probably give thought to underclocking it, but since my motherboard won't go lower than 1.10v, I figured stock speed at 1.14v was good enough.