Hardware Reference
In-Depth Information
The following combination of parameters may set a permanent bit in your
SoC chip and void your warranty. While the Raspberry Pi announcement
speaks of overclocking without voiding the warranty, it is subject to some conditions like
using the
cpufreq
driver. The following conditions may put your warranty in jeopardy:
ver_voltage
> 0, and at least one of the following:
•
force_turbo
= 1
•
current_limit_override
= 0x5A000020
•
temp_limit
> 85
•
Force Turbo Mode
The documentation indicates that
force_turbo
has no effect if other overclocking options
are in effect.
By default,
force_turbo
is disabled. When disabled, it disables some other
configuration options such as
h264_freq
. However, enabling
force_turbo
also enables
h264_freq
,
v3d_freq
, and
isp_freq
.
force_turbo
Description
0 (default)
Enables dynamic clocks and voltage for the ARM core, GPU core,
and SDRAM. In this mode, settings for
h264_freq
,
v3d_freq
, and
isp_freq
are ignored.
1
Disables dynamic clocks and voltage for the ARM core, GPU core,
and SDRAM. Configuration option values
h264_freq
,
v3d_freq
, and
isp_freq
apply when specified.
Initial Turbo
The
initial_turbo
option is described in
config.txt
as “enables turbo mode from boot
for the given value in seconds (up to 60).” This is somewhat confusing.
What is meant is that turbo mode will be enabled after a delay of a configured
number of seconds after boot. By default, if turbo mode is enabled, it is enabled
immediately (after examining
config.txt
).