cgminer doesn't detect GPU in ssh session I have AMD Radeon HD 6450 card and Ubuntu is my OS. If I log in normally and start cgminer it works properly and detect my graphic card. Now my monitor is turned off and I connect to my computer by ssh. In this scenario cgminer does not detect my graphic card:

[2013-12-22 13:35:09] Started cgminer 3.7.2
 [2013-12-22 13:35:09] clDevicesNum returned error, no GPUs usable
 [2013-12-22 13:35:09] No devices detected!
 [2013-12-22 13:35:09] Waiting for USB hotplug devices or press q to quit
 [2013-12-22 13:35:09] Probing for an alive pool
 [2013-12-22 13:35:09] Pool 0 difficulty changed to 256
 [2013-12-22 13:35:10] Network diff set to 3.23K


I suspect that the card is idle because monitor is turned off. To solve this I enabled X11 forwarding in my ssh session but It did not help. 

sudo aticonfig --lsa
* 0. 01:00.0 AMD Radeon HD 6450

* - Default adapter


What can be cause of that situation? Is possible that card is idle? How to check that and how to force card to starts?

EDIT

My cgminer start script:

#!/bin/sh
export DISPLAY=:0
export GPU_MAX_ALLOC_PERCENT=100
export GPU_USE_SYNC_OBJECTS=1
cd /mypath/cgminer-3.7.2-x86_64-built
./cgminer [parameters]


EDIT

sudo aticonfig --adapter=all --odgt
No protocol specified
No protocol specified
ERROR - X needs to be running to perform AMD Overdrive(TM) commands
The reason for this is that the X-Server that is handling the GPUs is not available in the SSH session. Try prefixing all commands with DISPLAY=:0. This tells cgminer which X-Server instance to use. The cgminer command then simply becomes:

DISPLAY=:0 ./cgminer -u ...


You can also fix this for the current session with the following

export DISPLAY=:0


this defines the variable in a bash shell (see your shell's documentation for details if you're using another shell). Putting this into your .bashrc file might be a good idea if you intend to use it only over SSH .