bash-2.05# prtdiag -v
System Configuration: Sun Microsystems sun4u Sun Ultra
5/10 UPA/PCI (UltraSPARC-IIi 297MHz)
System clock frequency: 99 MHz
Memory size: 256 Megabytes
========================= CPUs =========================
Run Ecache CPU CPU
Brd CPU Module MHz
MB Impl. Mask
--- --- ------- ----- ------ ------ ----
0 0 0
297 0.2 12
1.2
... and so on .. Don't forget to nvstore the also hidden command within your nvramrc !! And also, before going too high, be sure to test the system robustness, you probably don't want your system to do strange things during your daily work ... (sadness: tested and verified also in my 333Mhz U10, now running at the top speed also-hidden is capable to set in this machine : 370Mhz)