I have been mining since the patch went live Tuesday with a Deep Core II and Type A II Crystals for Merc.
Here is my current results per the mining ledger:

39.33% Total Waste isn’t 34%. Per my understanding of the notes, I have a 34% chance of wastage, but you would think over the course of 3.2 million m3 that the 34% should be more in line than 39.33%

You would, but it is still subject to statistics, so there is always going to be a normal distribution around that value and while you are on the high side, there are others that will be on the low side also.

The more you mine though, the closer you will approximate the 34% assuming there is no particular bias in the RNG.

The fun of (cumulative) binomial distributions. Brings back school memories.

The “34%” - or rather 34% from the deep core II + 3.6% (from the A-II crystal) = 37.6% - is, strictly speaking, not “waste” but the probability to create wasteper cycle.

If you’re interested in how this really works, here’s the breakdown:

the probability of producing waste on a cycle = 37.6% (or p=0.376), the probability of not having waste 1-p = 0.624 or 62.4%

the outcomes are mutually exclusive (you either produce waste or you don’t), hence binomial distribution can be used

the “sample size” n to calculate the probability of an outcome is the number of cycles you run on the mining tools during a session

In essence, it’s the number of cycles that did produce waste during the whole session that you need to compare with the 37.6% chance, not the volumes themselves (asteroid sizes vary hence a cycle doesn’t always pull or waste the same fixed amount). You can see what each cycle on your equipment pulls and wastes by going into the “Logs and Messages” utility, they are listed there. Only when that number of cycles becomes sufficiently large and closer to infinity will the number of cycles that did produce waste and the actual volume of waste approach a “waste per cycle volume of 37.6%”. You can even play around with cumulative binomial distributions to see if your outcome is to be expected or not (a handy tool for people who are mad when they fail 7 out of 10 jobs with a “success rate of 49%”).

An easy to use binomial distribution calculator, with graphs if you want them, can be found at https://www.di-mgt.com.au/binomial-calculator.html. The use and signficance of cumulative binomial distributions (“what is the probability that I get (more than/exactly/less than x successes/failures”), you will have to look that up yourself

To get back to the question of OP, it looks how it should be with that kind of probability and that sample size.

As others have noted, the Type A II crystals add another 3.6% waste chance, which makes the waste chance 37.6%, which is pretty close to the number you found.

Additionally, it seems that waste is applied first when cycling, so unless you use a scanner and strategically cut your last cycles short to avoid the chance of wasting all the ore in it before your yield applies, your total waste may come out a few percent higher.

Whether that extra effort is worth the extra yield is up to you.

You have 0 idea about how the waste mechanism works, I guess?

Mining modules have 2 new stats:

residue chance

residue multiplier

(or whatever their exact names are)

The second option is indeed how much ore you waste, which I guess you were thinking about. If you mine 1234 units, you waste 1234 units if your residue multiplier is 1x and you happen to get waste that cycle.

The other factor which you’re missing is that you’re not certain to get waste/residue each cycle. Whether that happens is chance based.

Now T1 modules have 0% chance and 0% residue. T2 modules have a 34% chance at 1x waste. T2 type A crystals add another 3.6% chance to make it a 37.6% chance at 1x waste.