EXECUTIVE SUMMARY ON GPU USAGE (SEE ALSO SCRYPT-README FOR SCRYPT MINING):

Single pool, regular desktop:

cgminer -o http://pool:port -u username -p password

By default if you have configured your system properly, cgminer will mine on
ALL GPUs, but in "dynamic" mode which is designed to keep your system usable
and sacrifice some mining performance.

Single pool, dedicated miner:

cgminer -o http://pool:port -u username -p password -I 9

Single pool, first card regular desktop, 3 other dedicated cards:

cgminer -o http://pool:port -u username -p password -I d,9,9,9

Multiple pool, dedicated miner:

cgminer -o http://pool1:port -u pool1username -p pool1password -o http://pool2:port -u pool2usernmae -p pool2password -I 9

Add overclocking settings, GPU and fan control for all cards:

cgminer -o http://pool:port -u username -p password -I 9 --auto-fan --auto-gpu --gpu-engine 750-950 --gpu-memclock 300

Add overclocking settings, GPU and fan control with different engine settings for 4 cards:

cgminer -o http://pool:port -u username -p password -I 9 --auto-fan --auto-gpu --gpu-engine 750-950,945,700-930,960 --gpu-memclock 300

READ WARNINGS AND DOCUMENTATION BELOW ABOUT OVERCLOCKING

To configure multiple displays on linux you need to configure your Xorg cleanly
to use them all:

sudo aticonfig --adapter=all -f --initial

On Linux you virtually always need to export your display settings before
starting to get all the cards recognised and/or temperature+clocking working:

export DISPLAY=:0

---
BUILDING FOR GPU SUPPORT:

	To build with GPU mining support:
	Install AMD APP sdk, ideal version (see FAQ!) - no official place to
	install it so just keep track of where it is if you're not installing
	the include files and library files into the system directory.
	(Do NOT install the ati amd sdk if you are on nvidia.)
	To build with GPU monitoring & clocking support:
	Extract the AMD ADL SDK, latest version - there is also no official
	place for these files. Copy all the *.h files in the "include"
	directory into cgminer's ADL_SDK directory.

The easiest way to install the ATI AMD SPP sdk on linux is to actually put it
into a system location. Then building will be simpler. Download the correct
version for either 32 bit or 64 bit from here:
	http://developer.amd.com/tools/heterogeneous-computing/amd-accelerated-parallel-processing-app-sdk/downloads/

The best version for Radeon 5xxx and 6xxx is v2.5, while 7xxx cards need
v2.6 or later, 2.7 seems the best.

For versions 2.4 or earlier you will need to manually install them:
This will give you a file with a name like:
 AMD-APP-SDK-v2.4-lnx64.tgz (64-bit)
or
 AMD-APP-SDK-v2.4-lnx32.tgz (32-bit)

Then:

sudo su
cd /opt
tar xf /path/to/AMD-APP-SDK-v2.4-lnx##.tgz
cd /
tar xf /opt/AMD-APP-SDK-v2.4-lnx##/icd-registration.tgz
ln -s /opt/AMD-APP-SDK-v2.4-lnx##/include/CL /usr/include
ln -s /opt/AMD-APP-SDK-v2.4-lnx##/lib/x86_64/* /usr/lib/
ldconfig

Where ## is 32 or 64, depending on the bitness of the SDK you downloaded.
If you are on 32 bit, x86_64 in the 2nd last line should be x86

Basic *nix build instructions:
	CFLAGS="-O2 -Wall -march=native" ./configure <options>
	or if you haven't installed the AMD files in system locations:
	CFLAGS="-O2 -Wall -march=native -I<path to AMD APP include>" LDFLAGS="-L<path to AMD APP lib/x86_64> ./configure <options>
	make

	If it finds the opencl files it will inform you with
	"OpenCL: FOUND. GPU mining support enabled."


---
INTENSITY INFORMATION:

Intensity correlates with the size of work being submitted at any one time to
a GPU. The higher the number the larger the size of work. Generally speaking
finding an optimal value rather than the highest value is the correct approach
as hash rate rises up to a point with higher intensities but above that, the
device may be very slow to return responses, or produce errors.

NOTE: Running BTC intensities above 9 with current hardware is likely to only
diminish return performance even if the hash rate might appear better. A good
starting baseline intensity to try on dedicated miners is 9. 11 is the upper
limit for intensity while BTC mining, if the GPU_USE_SYNC_OBJECTS variable
is set (see FAQ). The upper limit for sha256 mining is 14 and 20 for scrypt.


---
OVERCLOCKING WARNING AND INFORMATION

AS WITH ALL OVERCLOCKING TOOLS YOU ARE ENTIRELY RESPONSIBLE FOR ANY HARM YOU
MAY CAUSE TO YOUR HARDWARE. OVERCLOCKING CAN INVALIDATE WARRANTIES, DAMAGE
HARDWARE AND EVEN CAUSE FIRES. THE AUTHOR ASSUMES NO RESPONSIBILITY FOR ANY
DAMAGE YOU MAY CAUSE OR UNPLANNED CHILDREN THAT MAY OCCUR AS A RESULT.

The GPU monitoring, clocking and fanspeed control incorporated into cgminer
comes through use of the ATI Display Library. As such, it only supports ATI
GPUs. Even if ADL support is successfully built into cgminer, unless the card
and driver supports it, no GPU monitoring/settings will be available.

Cgminer supports initial setting of GPU engine clock speed, memory clock
speed, voltage, fanspeed, and the undocumented powertune feature of 69x0+ GPUs.
The setting passed to cgminer is used by all GPUs unless separate values are
specified. All settings can all be changed within the menu on the fly on a
per-GPU basis.

For example:
--gpu-engine 950 --gpu-memclock 825

will try to set all GPU engine clocks to 950 and all memory clocks to 825,
while:
--gpu-engine 950,945,930,960 --gpu-memclock 300

will try to set the engine clock of card 0 to 950, 1 to 945, 2 to 930, 3 to
960 and all memory clocks to 300.

AUTO MODES:
There are two "auto" modes in cgminer, --auto-fan and --auto-gpu. These can
be used independently of each other and are complementary. Both auto modes
are designed to safely change settings while trying to maintain a target
temperature. By default this is set to 75 degrees C but can be changed with:

--temp-target
e.g.
--temp-target 80
Sets all cards' target temperature to 80 degrees.

--temp-target 75,85
Sets card 0 target temperature to 75, and card 1 to 85 degrees.

AUTO FAN:
e.g.
--auto-fan (implies 85% upper limit)
--gpu-fan 25-85,65 --auto-fan

Fan control in auto fan works off the theory that the minimum possible fan
required to maintain an optimal temperature will use less power, make less
noise, and prolong the life of the fan. In auto-fan mode, the fan speed is
limited to 85% if the temperature is below "overheat" intentionally, as
higher fanspeeds on GPUs do not produce signficantly more cooling, yet
significanly shorten the lifespan of the fans. If temperature reaches the
overheat value, fanspeed will still be increased to 100%. The overheat value
is set to 85 degrees by default and can be changed with:

--temp-overheat
e.g.
--temp-overheat 75,85
Sets card 0 overheat threshold to 75 degrees and card 1 to 85.

AUTO GPU:
e.g.
--auto-gpu --gpu-engine 750-950
--auto-gpu --gpu-engine 750-950,945,700-930,960

GPU control in auto gpu tries to maintain as high a clock speed as possible
while not reaching overheat temperatures. As a lower clock speed limit,
the auto-gpu mode checks the GPU card's "normal" clock speed and will not go
below this unless you have manually set a lower speed in the range. Also,
unless a higher clock speed was specified at startup, it will not raise the
clockspeed. If the temperature climbs, fanspeed is adjusted and optimised
before GPU engine clockspeed is adjusted. If fan speed control is not available
or already optimal, then GPU clock speed is only decreased if it goes over
the target temperature by the hysteresis amount, which is set to 3 by default
and can be changed with:
--temp-hysteresis
If the temperature drops below the target temperature, and engine clock speed
is not at the highest level set at startup, cgminer will raise the clock speed.
If at any time you manually set an even higher clock speed successfully in
cgminer, it will record this value and use it as its new upper limit (and the
same for low clock speeds and lower limits). If the temperature goes over the
cutoff limit (95 degrees by default), cgminer will completely disable the GPU
from mining and it will not be re-enabled unless manually done so. The cutoff
temperature can be changed with:

--temp-cutoff
e.g.
--temp-cutoff 95,105
Sets card 0 cutoff temperature to 95 and card 1 to 105.

--gpu-memdiff -125
This setting will modify the memory speed whenever the GPU clock speed is
modified by --auto-gpu. In this example, it will set the memory speed to
be 125 Mhz lower than the GPU speed. This is useful for some cards like the
6970 which normally don't allow a bigger clock speed difference. The 6970 is
known to only allow -125, while the 7970 only allows -150.


CHANGING SETTINGS:
When setting values, it is important to realise that even though the driver
may report the value was changed successfully, and the new card power profile
information contains the values you set it to, that the card itself may
refuse to use those settings. As the performance profile changes dynamically,
querying the "current" value on the card can be wrong as well. So when changing
values in cgminer, after a pause of 1 second, it will report to you the current
values where you should check that your change has taken. An example is that
6970 reference cards will accept low memory values but refuse to actually run
those lower memory values unless they're within 125 of the engine clock speed.
In that scenario, they usually set their real speed back to their default.

Cgminer reports the so-called "safe" range of whatever it is you are modifying
when you ask to modify it on the fly. However, you can change settings to values
outside this range. Despite this, the card can easily refuse to accept your
changes, or worse, to accept your changes and then silently ignore them. So
there is absolutely to know how far to/from where/to it can set things safely or
otherwise, and there is nothing stopping you from at least trying to set them
outside this range. Being very conscious of these possible failures is why
cgminer will report back the current values for you to examine how exactly the
card has responded. Even within the reported range of accepted values by the
card, it is very easy to crash just about any card, so it cannot use those
values to determine what range to set. You have to provide something meaningful
manually for cgminer to work with through experimentation.

STARTUP / SHUTDOWN:
When cgminer starts up, it tries to read off the current profile information
for clock and fan speeds and stores these values. When quitting cgminer, it
will then try to restore the original values. Changing settings outside of
cgminer while it's running may be reset to the startup cgminer values when
cgminer shuts down because of this.

---

GPU DEVICE ISSUES and use of --gpu-map

GPUs mine with OpenCL software via the GPU device driver. This means you need
to have both an OpenCL SDK installed, and the GPU device driver RUNNING (i.e.
Xorg up and running configured for all devices that will mine on linux etc.)
Meanwhile, the hardware monitoring that cgminer offers for AMD devices relies
on the ATI Display Library (ADL) software to work. OpenCL DOES NOT TALK TO THE
ADL. There is no 100% reliable way to know that OpenCL devices are identical
to the ADL devices, as neither give off the same information. cgminer does its
best to correlate these devices based on the order that OpenCL and ADL numbers
them. It is possible that this will fail for the following reasons:

1. The device order is listed differently by OpenCL and ADL (rare), even if the
number of devices is the same.
2. There are more OpenCL devices than ADL. OpenCL stupidly sees one GPU as two
devices if you have two monitors connected to the one GPU.
3. There are more ADL devices than OpenCL. ADL devices include any ATI GPUs,
including ones that can't mine, like some older R4xxx cards.

To cope with this, the ADVANCED option for --gpu-map is provided with cgminer.
DO NOT USE THIS UNLESS YOU KNOW WHAT YOU ARE DOING. The default will work the
vast majority of the time unless you know you have a problem already.

To get useful information, start cgminer with just the -n option. You will get
output that looks like this:

[2012-04-25 13:17:34] CL Platform 0 vendor: Advanced Micro Devices, Inc.
[2012-04-25 13:17:34] CL Platform 0 name: AMD Accelerated Parallel Processing
[2012-04-25 13:17:34] CL Platform 0 version: OpenCL 1.1 AMD-APP (844.4)
[2012-04-25 13:17:34] Platform 0 devices: 3
[2012-04-25 13:17:34]   0       Tahiti
[2012-04-25 13:17:34]   1       Tahiti
[2012-04-25 13:17:34]   2       Cayman
[2012-04-25 13:17:34] GPU 0 AMD Radeon HD 7900 Series  hardware monitoring enabled
[2012-04-25 13:17:34] GPU 1 AMD Radeon HD 7900 Series  hardware monitoring enabled
[2012-04-25 13:17:34] GPU 2 AMD Radeon HD 6900 Series hardware monitoring enabled
[2012-04-25 13:17:34] 3 GPU devices max detected

Note the number of devices here match, and the order is the same. If devices 1
and 2 were different between Tahiti and Cayman, you could run cgminer with:
--gpu-map 2:1,1:2
And it would swap the monitoring it received from ADL device 1 and put it to
opencl device 2 and vice versa.

If you have 2 monitors connected to the first device it would look like this:

[2012-04-25 13:17:34] Platform 0 devices: 4
[2012-04-25 13:17:34]   0       Tahiti
[2012-04-25 13:17:34]   1       Tahiti
[2012-04-25 13:17:34]   2       Tahiti
[2012-04-25 13:17:34]   3       Cayman
[2012-04-25 13:17:34] GPU 0 AMD Radeon HD 7900 Series  hardware monitoring enabled
[2012-04-25 13:17:34] GPU 1 AMD Radeon HD 7900 Series  hardware monitoring enabled
[2012-04-25 13:17:34] GPU 2 AMD Radeon HD 6900 Series hardware monitoring enabled

To work around this, you would use:
-d 0 -d 2 -d 3 --gpu-map 2:1,3:2

If you have an older card as well as the rest it would look like this:

[2012-04-25 13:17:34] Platform 0 devices: 3
[2012-04-25 13:17:34]   0       Tahiti
[2012-04-25 13:17:34]   1       Tahiti
[2012-04-25 13:17:34]   2       Cayman
[2012-04-25 13:17:34] GPU 0 AMD Radeon HD 4500 Series  hardware monitoring enabled
[2012-04-25 13:17:34] GPU 1 AMD Radeon HD 7900 Series  hardware monitoring enabled
[2012-04-25 13:17:34] GPU 2 AMD Radeon HD 7900 Series  hardware monitoring enabled
[2012-04-25 13:17:34] GPU 3 AMD Radeon HD 6900 Series hardware monitoring enabled

To work around this you would use:
--gpu-map 0:1,1:2,2:3


---
GPU FAQ:

Q: Can I change the intensity settings individually for each GPU?
A: Yes, pass a list separated by commas such as -I d,4,9,9

Q: The CPU usage is high.
A: The ATI drivers after 11.6 have a bug that makes them consume 100% of one
CPU core unnecessarily so downgrade to 11.6. Binding cgminer to one CPU core on
windows can minimise it to 100% (instead of more than one core). Driver version
11.11 on linux and 11.12 on windows appear to have fixed this issue. Note that
later drivers may have an apparent return of high CPU usage. Try
'export GPU_USE_SYNC_OBJECTS=1' on Linux before starting cgminer. You can also
set this variable in windows via a batch file or on the command line before
starting cgminer with 'setx GPU_USE_SYNC_OBJECTS 1'

Q: My GPU hangs and I have to reboot it to get it going again?
A: The more aggressively the mining software uses your GPU, the less overclock
you will be able to run. You are more likely to hit your limits with cgminer
and you will find you may need to overclock your GPU less aggressively. The
software cannot be responsible and make your GPU hang directly. If you simply
cannot get it to ever stop hanging, try decreasing the intensity, and if even
that fails, try changing to the poclbm kernel with -k poclbm, though you will
sacrifice performance. cgminer is designed to try and safely restart GPUs as
much as possible, but NOT if that restart might actually crash the rest of the
GPUs mining, or even the machine. It tries to restart them with a separate
thread and if that separate thread dies, it gives up trying to restart any more
GPUs.

Q: Can you change the autofan/autogpu to change speeds in a different manner?
A: The defaults are sane and safe. I'm not interested in changing them
further. The starting fan speed is set to 50% in auto-fan mode as a safety
precaution.

Q: I upgraded cgminer version and my hashrate suddenly dropped!
A: No, you upgraded your SDK version unwittingly between upgrades of cgminer
and that caused  your hashrate to drop. See the next question.

Q: I upgraded my ATI driver/SDK/cgminer and my hashrate suddenly dropped!
A: The hashrate performance in cgminer is tied to the version of the ATI SDK
that is installed only for the very first time cgminer is run. This generates
binaries that are used by the GPU every time after that. Any upgrades to the
SDK after that time will have no effect on the binaries. However, if you
install a fresh version of cgminer, and have since upgraded your SDK, new
binaries will be built. It is known that the 2.6 ATI SDK has a huge hashrate
penalty on generating new binaries. It is recommended to not use this SDK at
this time unless you are using an ATI 7xxx card that needs it.

Q: Which AMD SDK is the best for cgminer?
A: At the moment, versions 2.4 and 2.5 work the best for R5xxx and R6xxx GPUS.
SDK 2.6 or 2.7 works best for R7xxx. SDK 2.8 is known to have many problems.
If you are need to use the 2.6+ SDK or R7xxx or later, the phatk kernel will
perform poorly, while the diablo or my custom modified poclbm kernel are
optimised for it.

Q: Which AMD driver is the best?
A: Unfortunately AMD has a history of having quite a few releases with issues
when it comes to mining, either in terms of breaking mining, increasing CPU
usage or very low hashrates. Only experimentation can tell you for sure, but
some good releases were 11.6, 11.12, 12.4 and 12.8. Note that older cards may
not work with the newer drivers.

Q: I have multiple SDKs installed, can I choose which one it uses?
A: Run cgminer with the -n option and it will list all the platforms currently
installed. Then you can tell cgminer which platform to use with --gpu-platform.

Q: cgminer reports no devices or only one device on startup on Linux although
I have multiple devices and drivers+SDK installed properly?
A: Try "export DISPLAY=:0" before running cgminer.

Q: cgminer crashes immediately on startup.
A: One of the common reasons for this is that you have mixed files on your
machine for the driver or SDK. Windows has a nasty history of not cleanly
uninstalling files so you may have to use third party tools like driversweeper
to remove old versions. The other common reason for this is windows
antivirus software is disabling one of the DLLs from working. If cgminer
starts with the -T option but never starts without it, this is a sure fire
sign you have this problem and will have to disable your antivirus or make
exceptions.

Q: Cgminer cannot see any of my GPUs even though I have configured them all
to be enabled and installed OpenCL (+/- Xorg is running and the DISPLAY
variable is exported on linux)?
A: Check the output of 'cgminer -n', it will list what OpenCL devices your
installed SDK recognises. If it lists none, you have a problem with your
version or installation of the SDK.

Q: Cgminer is mining on the wrong GPU, I want it on the AMD but it's mining
on my on board GPU?
A: Make sure the AMD OpenCL SDK is installed, check the output of 'cgminer -n'
and use the appropriate parameter with --gpu-platform.

Q: I'm getting much lower hashrates than I should be for my GPU?
A: Look at your driver/SDK combination and disable power saving options for
your GPU. Specifically look to disable ULPS. Make sure not to set intensity
above 11 for BTC mining.

Q: Can I mine with AMD while running Nvidia or Intel GPUs at the same time?
A: If you can install both drivers successfully (easier on windows) then
yes, using the --gpu-platform option.

Q: Can I mine with Nvidia or Intel GPUs?
A: Yes but their hashrate is very poor and likely you'll be using much more
energy than you'll be earning in coins.

Q: Can I mine on both Nvidia and AMD GPUs at the same time?
A: No, you must run one instance of cgminer with the --gpu-platform option for
each.

Q: Can I mine on Linux without running Xorg?
A: With Nvidia you can, but with AMD you cannot.

Q: I can't get anywhere near enough hashrate for scrypt compared to other
people?
A: You may not have enough system RAM as this is also required.

Q: My scrypt hashrate is high but the pool reports only a tiny proportion of
my hashrate?
A: You are generating garbage hashes due to your choice of settings. Your
Work Utility (WU) value will confirm you are not generating garbage. You
should be getting about .9WU per kHash. If not, then try decreasing your
intensity, do not increase the number of gpu-threads, and consider adding
system RAM to match your GPU ram. You may also be using a bad combination
of driver and/or SDK. If you are getting a lot more HW errors with the
current version of cgminer but were not on an older version, chances are that
the older version simply wasn't reporting them so going back to and older
version is not a real solution.

Q: Scrypt fails to initialise the kernel every time?
A: Your parameters are too high. Don't add GPU threads, don't set intensity
too high, decrease thread concurrency. See the SCRYPT-README for a lot more
help.

Q: Cgminer stops mining (or my GPUs go DEAD) and I can't close it?
A: Once the driver has crashed, there is no way for cgminer to close cleanly.
You will have to kill it, and depending on how corrupted your driver state
has gotten, you may even need to reboot. Windows is known to reset drivers
when they fail and cgminer will be stuck trying to use the old driver instance.
GPUs going SICK or DEAD is a sign of overclocking too much, overheating,
driver or hardware instability.

Q: I can't get any monitoring of temperatures or fanspeed with cgminer when
I start it remotely?
A: With linux, make sure to export the DISPLAY variable. On windows, you
cannot access these monitoring values via RDP. This should work with tightVNC
or teamviewer though.

Q: I change my GPU engine/memory/voltage and cgminer reports back no change?
A: Cgminer asks the GPU using the ATI Display Library to change settings, but
the driver and hardware are free to do what it wants with that query, including
ignoring it. Some GPUs are locked with one or more of those properties as well.
The most common of these is that many GPUs only allow a fixed difference
between the engine clock speed and the memory clock speed (such as the memory
being no lower than the engine - 150). Other 3rd party tools have unofficial
data on these devices on windows and can get the memory clock speed down
further but cgminer does not have access to these means.

Q: I have multiple GPUs and although many devices show up, it appears to be
working only on one GPU splitting it up.
A: Your driver setup is failing to properly use the accessory GPUs. Your
driver may be configured wrong or you have a driver version that needs a dummy
plug on all the GPUs that aren't connected to a monitor.

Q: Should I use crossfire/SLI?
A: It does not benefit mining at all and depending on the GPU may actually
worsen performance.

Q: I have some random GPU performance related problem not addressed above.
A: Seriously, it's the driver and/or SDK. Uninstall them and start again,
noting there is no clean way to uninstall them so you have to use extra tools
or do it manually.

Q: Do I need to recompile after updating my driver/SDK?
A: No. The software is unchanged regardless of which driver/SDK/ADL_SDK version
you are running. However if you change SDKs you should delete any generated
.bin files for them to be recreated with the new SDK.

Q: I do not want cgminer to modify my engine/clock/fanspeed?
A: Cgminer only modifies values if you tell it to via some parameters.
Otherwise it will just monitor the values.

Q: Cgminer does not disable my GPU even though it hit the overheat temperature?
A: It only disables GPUs if you enable the --auto-gpu option. If you don't give
it parameters for engine clock it will not adjust engine clocks with this
option.

Q: Can I use the open source radeon driver for AMD GPUs or the nouveau driver
for NVIDIA GPUs?
A: None of them currently support OpenCL, so no you cannot.

---

This code is provided entirely free of charge by the programmer in his spare
time so donations would be greatly appreciated. Please consider donating to the
address below.

Con Kolivas <kernel@kolivas.org>
15qSxP1SQcUX3o4nhkfdbgyoWEFMomJ4rZ