I did some test with exactly the same disk and got slightly different results. So, how reliable are these tests?
Ofcourse it’s gonna be different, this is not a solid state device and cdspeed is only as reliable as YOUR DRIVE!
Looks pretty damn reliable to me. Your tests are almost identical. Of course you will never get identical scans from even the same drive and disk.
One piece of dust on the disc can cause the results to be different.
Even with exactly the same disc, there will be slight differences in the vibrations of the spinning disc, tiny power fluctuations in your machine, the physical size of the disc due to temperature fluctuations, etc.
Therefore you will never get identical scans from the same disc. Of course for high quality discs, they will always give scans (on the same scanning drive) that are pretty similar. That seems to be the case right here.
The worst scan averages 1.32 PI, Peak 9, the best 1.05 PI, peak 8
For PIF, even closer, 0.09 peak 5 and 0.08 peak 6.
I’d rate those as good scans, and well correlated … Low/steady PI, spilling into low/scattered PIF - that cluster at the end suggests a longer burn might not be as clean beyond there.