Presumably as loud as the S7 miners are.
Indeed they are or as loud as any of the new ones from but main around 76 DB . but you can either make a sound box or buy one off ebay and run it at 100 % an even over clocked it if you want in the box the DB drop to normal levels or were you can sleep in the same room . I made a sound box /hotbox whatever you want a call it for one of my D3's and it works Great .....
yes you should right now till id say some time into the 3Q of this year, it won't be much you might even hit ROI if that's your bag or worry because of the price of the miner an depending on what the Diff stays at with them testing new stuff . . with solar it's the same just watch the meters with solar an the disconnect to the power company at nite unless your off the gild . . if your power is high without using solar .
an yes again i can't believe there is fools still selling S7 for more then the V9 i just hope whoever buys these things shops and learns not to buy a S7 when the V9 is basically a S7 at a lot cheaper price. it amazes me the greed of some... when there is more then enough to go around .
Moderator's note: This post was edited by frodocooper to correct erroneous quote formatting.