I found some low sec rocks in an escalation site and decided to mine them. It has been years since I did any mining and was vaguely familiar with the new changes. Throughout the whole process, I was using mining crystals type A 1 with a modulated strip miner tech 2 mounted on an exhumer. I was keeping the hold empty to avoid any loss by having no room.
You mined 3208 units of Omber with a lost residue of 0 units.
This was repeated multiple times until the asteroid was depleted. But the next few asteroids would start with the same 0 units of lost residue for a few rounds, but then -
You mined 3208 units of Omber with a lost residue of 2959 units and the asteroid would be done.
You mined 3208 units of Omber with a lost residue of 1542 units and the asteroid would be done.
The next asteroid had the worst result -
You mined 3208 units of Omber with a lost residue of 3208 units and the asteroid would be done.
I am wondering why the losses were not consistent. The only aspect I noted was it seemed whenever I had a large loss of residue, my mining crystal was taking a heavy damage hit simultaneously. And by heavy, one crystal at 88% damage broke apart and was lost. I remember the old crystals damaging in smaller amounts - nothing in the double digits in one round.
Think of it like sand- as you pull your handful out theres always the lil bit that falls through fingers, caves in the side of the pit, the bit you wipe off =all of that would be residual losses that occur every so often. T1 mods dont produce residuals along with ORE mods.
With T2 mining lasers and type A I crystals your modulated strip miner has 34% residue probability with a 1x residue multiplier.
Type A crystals are the most efficient T2 mining option and have decent yield, but even those waste some of the ore inside the rocks, but can make up with it with the much faster yield. While T1 mining equipment is more efficient and causes no residue, it’s significantly slower.
The residue multiplier and residue chance can be seen in the info stats of your module. What these values mean is that when you mine ore, 3208 ore in your case with your yield, you have a 34% chance of also depleting 1x (your yield value, which is 3208) ore from the asteroid. 66% of the time you get the message:
“You mined 3208 units of Omber with a lost residue of 0 units.”
and 34% of the time you get the message
“You mined 3208 units of Omber with a lost residue of 3208 units.”
The reason the residue values were not consistent is because there no longer were 3208 units in the rock, so it simply depleted whatever number was left. 2959, or 1542 ore removed, and the asteroid is gone.
Fun fact: It used to be worse, right after residue was introduced the game would first remove ore before trying to mine the remainder. You would get messages like:
“You mined 1542 units of Omber with a lost residue of 3208 units and the asteroid would be done.”
But CCP changed it so that you first mine ore and then roll for residue.
Residue Loss with T2 Crystals or Miners is 34% chance. The loss is equal to the amount mined. When your mining loss did not equal your mined amount, your loss was the remaining amount of the asteroid. So when your rock has more than double your harvest, example: asteroid is 10k m3 and you mine 3208 each cycle, your residue chance is 34% to lose 3208 to loss. this brings your rock size down to 3584 m3 remaining… your next cycle has residue chance if it triggers, you mine 3208 and residue would be 376 m3. You see the math.
You will accumulate the 3208 in your hold but the residue is subtracted from the remaining amount of the asteroid. This is unrecoverable loss. Its the cost of using T2 equipment.
After all, asteroid sizes all got 100% more ore, so if excavator drones would have had 100% residue chance it would have been the same as before the update that introduced residue.
At 60% residue chance you get more: 25% more ore out of the asteroids with excavator drones than before that change, which is a nice buff.
Of course with lower residue chance at other mining equipment you have other options now if you want efficient mining, which make excavator drones relatively worse than the powerhouse they were before, but that doesn’t change the fact that the amount of ore excavators pull out of asteroids was buffed in that patch.