How to use -gt (GPU tuning, what does it do)? I dont seem to find any value that would make a difference.
Using the -gt tuning can make a worthwhile increase in your hash rates.
This is only used for AMD cards.
Here is how I found the best way to tune and use it.
Have your miner up and running.
Using the '+' key increase the tuning parameter to a larger number than you need.
Start out at 100.
Watch your displayed hash rate in the mining window.
Let it display a few updates to see where the speed is currently running.
Decrease the tuning number by 10 using the '-' key.
Watch the hash rate.
Continue decreasing the number by 10 on each test while watching the hash rates.
You should see the hash rate starting to increase as you go down in numbers.
The hash rate will increase and then start to decrease.
When you reach that point you are close.
Now start going up and down by 5 instead of 10 on each test.
You will eventually find the sweet spot where you can't improve it any more.
Set that number in the -gt parameter in your config.txt file.
If you have multiple GPU's in a system you will need to do this for each GPU.
Disable all the GPU's but one. Find the best number for that GPU.
Record that number then disable that GPU and enable the next one.
Repeat until you have all the setting for each GPU.
This can take some time, but its worth it.
Isn't there a way to automate this? Have the miner calculate a moving average while it's changing this parameter, thus finding out the best for each card.
cards" does sound appealing.