Hardware Reference
In-Depth Information
The following commands can be used to check your CPU, once you have a
command-line prompt. The
/proc/cpuinfo
pseudo file will give you a BogoMIPS figure:
$ cat /proc/cpuinfo
Processor : ARMv6−compatible processor rev 7 ( v6l )
BogoMIPS : 697.95
Features : swp half thumb fastmult vfp edsp java tls
CPU implementer : 0x41
CPU architecture : 7
CPU variant : 0x0
CPU part : 0xb76
CPU revision : 7
Hardware : BCM2708
Revision : 000f
Serial : 00000000 f52b69e9
$
The
vcgencmd
can be used to read the ARM CPU clock frequency:
$ vcgencmd measure_clock arm
frequency (45)=700074000
$
To configure for overclocking, you start with the phase-locked loop (PLL). The PLL
frequency is computed as follows:
æ
ç
2400
2
ö
÷
()
pfloor
=
2
c
c
where
•
p
is the computed PLL frequency.
•
c
is the core frequency.
From this, the GPU frequency multiple
m
is computed from a trial GPU frequency
t
as follows:
p
t
m
=
The value
m
is then rounded to the nearest
even
integer value, and the
final
GPU
frequency
g
is computed as follows:
p
m
g
=
