Laser 20w, $30= 1000 in lightburn S-value max=2000, laser works perfectly with adequate power. If I set the same laser to S-value max=1000, it works as if it were 10w!?!? Thanks
How are you determining this?
It’s likely with that setting that any power level over 50% is resulting in full power at all times.
Try a test. Enable “Constant Power Mode” in cut settings and compare 50% power at 2000 S Value Max vs 100% power at 1000 with a simple design. Do not run long at that power due to risk of overheating.
I have two lasers. one module is 10w and the other 22w. When I set the speed to 1000 and the power to 80%, three passes. The same results are for the 10w laser and the 22w laser if the S-value max is 1000. When I set the speed to 100/80% and the S-value max 2000 for the 20w laser, then 2 passes are required. When engraving wood, speed 8000/19%, both lasers have the same engraving. logically, a 22w laser would need less power compared to a 10w laser
You’re mixing variables.
Is the real question why are you not getting the results you expect from a 20W laser?
Or are you asking about how S Value Max should be working?
Unless you have a fundamental hardware issue, going to 2000 for S Value Max when $30 is set to 1000 will not have the effect of doubling your power. It will serve to make all power levels 50% or higher to be the max power.
You can measure this if you have a voltmeter. Test PWM voltage from the controller. For an Ortur machine you’ll get ~5V for any power setting 50% or higher.
I also suggest you run the test I described previously using Constant Power Mode. That will eliminate any power modulation as a variable in the test.
Thank you 
Lightburn-Device setings-S-value max 2000, $30=1000
Not following what you’re trying to say here. Can you elaborate?
You need to compare the 50% power at S Value Max of 2000 with 100% of S Value Max of 1000. I think you’ll find that the cuts are the same.
Make sure to enable Constant Power Mode.