2175 is pretty damn high for the memory clock 24/7. Remember, these memory chips were designed to run at 16Ghz (2000 clock), the ones that made the cut went into the 16ghz GPU's (like the Rx 580 8Gb, the Rx 590 ) and the ones that didnt were slapped onto boffins at 14Ghz ( 1750 clock) and even lower end 12Ghz (1500 clock). While you CAN oc them to speeds over 2000, its generally recommended to keep the speeds as low as possible and achieving higher hashrate with tighter timings ( better straps ) - keeps the chips from burning out. You NEED to undervolt the memory for 24/7 use and not use it at stock volts. So a 1500 strap running at say 1925 is preferable to a 1625 strap running at 2125 for a similar hashrate.
Well, is nothing wrong in keeping on that if is running without problems and keep it cool, after sometime he will have to lower those clocks anyway. Funny though, this is the reason there are so people complain about their hashrate, so many invalid shares due to that. I have a rx 480 here which was 2155 for 4 years then for some reason it does not keep like that anymore, I had to lower to 2000mhz for it to be stable few weeks ago, but it has run for 4 years at 2155 without problems.