1. proof has been given by multiple people in this thread so read up buddy.

2. they do not care about roi...they got paid upfront multiple times more than the cost of the machine so they only care about getting past the 180 day threshold with the buyer and not about if the miner runs or not. their warranty also says if anything burns up due to component failure (which is common for almost all component failures especially ones with high amounts of power running through them lol) the warranty is voided out so again they dont care how long they last past a set amount of time they have determined in house. they wouldnt publicly post that info either because it can cost them business. its sort of like the well believed "planned obsolesce" in the tech/appliance/consumer products in general industry. if companies made them to last customers wouldnt consider buying replacements as fast and in bitmains case if 1 s9 dies thats 1 less s9 competition against them. they get their money and reduced competition at the mining lvl. that is what is known as a win win my friend. are u familiar with that term??

3. im not sure why your bolding the word "ARE" like im disagreeing with your classification lol but whatevs buddy. ne way lowering the freq of the chip makes the chip use less power. the voltage can go up all it wants the fact is the current draw goes down which when you do the math equals less wattage being used which again proves it uses less power. im not sure what argument your trying to win but it seems like your confirming what i said in over what....20+ posts now?? ty i guess lol.

4. i guess u have to have run a gpu mining farm (only 145 cards but for me that seemed like alot. others dont have to agree) to be able to comment on it so since u havent i will share some info on how i did things. my gpus wouldnt run at higher than 80% capacity. i treated them like i would treat a power supply and never maxed it out past 80% except for when im finding the sweet spot for that config. each card has slight differences so the sweet spot may or may not be the same as every other card your running of the same model/specs. besides you cant know what 80% capacity of that particular card is until u know what the max it can handle is...its common sense.  maybe i was too anal and maybe not but i know my gpus didnt die. they also didnt need to be repasted like other gpus i tried buying that were run at 100%. they were unloading them in a bulk sale but i wanted to check the paste beforehand to see how they were treated and good thing i did....it had become completely useless. meanwhile mine until the day i sold them all (xfx 7950 DD's) had 0 of the same issues the other cards i was looking at buying in bulk had. i also tried buying the cards from other miners locally as well and they had the same problems so it wasnt a 1 time fluke associated with 1 deal so sorry buddy but if u just looked the info up u would know all of this. i mean ur super techy right?? u werent around during the crazy days of nvidia 8800 series video cards in both laptops and desktops and how they would overheat?? i guess thats one notch in the child column lol.