Provided by: nvclock_0.8b4+cvs20100914-5_amd64 
NAME
nvclock - Overclock your nVidia graphics adapter.
SYNOPSIS
nvclock [options]
DESCRIPTION
This manual page documents briefly the nvclock command. NVClock is a small program for
tweaking nVidia videocards on FreeBSD, Linux and Windows. Originally it was only meant for
overclocking but these days it can do much more. For instance it contains hardware
monitoring support using which you can view the temperatures and fanspeeds on cards that
support it. Further it allows tweaking of OpenGL settings using the NV-CONTROL extension
supported by the nVidia Linux/FreeBSD drivers.
OPTIONS
The program follows the usual GNU command line syntax, with long options starting with two
dashes (`-'). A summary of options are included below.
--b, --backend backend
By default NVClock uses its so called 'low-level' backend for reading and adjusting
the clockspeeds of cards. Since NVidia driver 1.0-7667 the drivers also provide an
overclocking mechanism called 'Coolbits'. It is only supported on desktop versions
of the GeforceFX/6/7. The main advantages it has over the low-level backend is that
it allows you to set the clocks to use in 2D and 3D programs. The problem is that
various modern GeforceFX/6/7/8 cards run at different clockspeeds depending if you
are running a 3D application or not.
Possible values for backend are: coolbits, coolbits2d, coolbits3d and lowlevel. The
default option on GeforceFX/6/7 cards is coolbits which sets the same clocks for
2D/3D, further coolbits2d and coolbits3d set respectively the 2D and 3D clocks and
finally lowlevel lets you use the lowlevel backend.
-c, --card number
Most systems only contain only one videocard. On systems with multiple cards, this
option can be used to select the card to overclock.
-d, --debug
Enable/Disable overclocking related debug info. This information shows the data
stored in the PLLs during various operations.
-D, --Debug
Print a long list of GPU registers containing their current value. All this info is
very useful for debugging.
-f, --force
Force support for a card that is currently disabled. Cards can be disabled by
default if the code for them is experimental or in case a Laptop is being used.
Laptops are disabled for safety reasons as overclocking on them is more dangerous.
In case you know what you are doing you can use this option to enable downclocking
of your GPU as a way to save power.
-F, --fanspeed speed
Using this option you can adjust the duty cycle of the fanspeed. The value you can
enter can be a delta like +10 or -10 which increases/decreases the fanspeed with
10%. Further the value can be a number like 20 which would set the fanspeed to 20%.
Further if your sensor supports automatic (temperature controlled) fanspeed
adjustments you can also use the value 'auto' to switch back to automatic control.
Note that in all cases the (final) fanspeed should lie between 10% and 100%. A low
duty cycle correspons to a low fanspeed.
Note that the duty cycle is NOT the fanspeed. The duty cycle controls the
percentage of time in a fixed time interval in which the fan is 'on'. By choosing a
higher value the fan is enabled a larger part of the time which results in a higher
fanspeed. Changing the duty cycle from 20% to 40% doesn't double the noise or
fanspeed.
-i, --info
Print detailed card info
-m, --memclk speed
Memory speed in MHz
-n, --nvclk speed
Core speed in MHz
-P, --Punit mask
The Geforce6/7 are designed in such a way that one single GPU can be used for
creating different types of boards. For instance they produce a NV40 (6800-class)
GPU and when the GPU is functioning properly they turn it into a 6800GT/Ultra or
when something is damaged or when it can't reach high clocks they call it a
6800NU/LE. The same is the case for NV43 based 6200/6600 cards. A 6800LE card ships
with 8 disabled pixel units and 2 disabled vertex units. On various cards it is
possible to re-enable those units and if it works correctly it can greatly improve
3D performance. The problem is that some units can be broken which results in
artifacts or instability. Further not all GPU models can be unlocked either because
Nvidia protected the GPUs against modding or because there are no extra units to
enable.
Using this option you can enable extra pixel units. First check using the -i switch
which pixel units are masked. If none are masked it means that none can be
unlocked. For an explanation I will take a 6800LE as an example which by default
has 8 of its 16 pixel units disabled. The -i option showed the mask '1100' which
means that the first and second block of pixel units are disabled. One block of
pixel unit contains 4 pipelines in case of most boards with the exception of
NV44/NV46 which use 2 pipelines for each pixel unit. To enable the first and second
pipeline use -P 1111 (binary) or i you prefer hex 0xf. NVClock will then try to
unlock the pipelines note that even when there are masked pipelines some can be
locked in hardware so that they can't be enabled.
-r, --reset
Restore the original clockspeeds
-s, --speeds
Print current clockspeeds in MHz
-S, --smartdimmer
For use on laptops Nvidia added functionality called smartdimmer which can be used
to adjust the brightness of the backlight. At the moment the feature is limited to
Geforce6200Go cards but if needed more cards can be added if they really provide
Smartdimmer support. To use this option you can select a value between 15% and 100%
and the brightness will be set to that level or you can use a delta like +10 / -10
which should decrease the brightness with +10% / -10%.
-V, --Vunit mask
This option can be used to enable disabled vertex pipelines which can appear on
Geforce6/7 cards. For an introduction to pipeline modding check the -P option
first. The syntax and working option is the same as the pixel unit one with the
difference that one bit corresponds to 1 vertex pipeline instead of multiple. Again
check -i to see which vertex units are locked. On a 6800LE you might see '001111'
which means that the fifth and sixth unit are locked. To enable all units use -V
111111 (binary) or 0x3f (hex). Note that it isn't certain that a unit can be
enabled as on some cards units are locked.
Below is a list with Display / OpenGL related options
-l, --list
List OpenGL / Display options supported by your chipset/driver
-q, --query option
Query current setting for one of the options listed under OpenGL / Display options.
-a, --assign option / option[display]="value"
Set a value for a supported option.
For OpenGL options like fsaa the following syntax is enough: nvclock -a
option=value
Display specific options like Digital Vibrance sometimes need the display name:
nvclock -a vibrance[crt-0]=value.
-x, --xdisplay
Choose another X display
-h, --help
Show summary of options.
AUTHOR
This manual page was originally written by Wouter de Vries <sax@debian.org>, for the
Debian GNU/Linux system. Later on it got an update by Kel Modderman <kelrin@tpg.com.au>
and at last it got rewritten for inclusion in NVClock 0.8 by Roderick Colenbrander
<thunderbird@linuxhardware.org>
0.8beta3 NVCLOCK(1)