Without any problem, withoutn crash. Sapphire RX470 4GB Nitro+ (moded bios)
That's probably Samsung memory you've got there? Those can usually overclock to 2100+ with 1750 strap timings. But most 470s, as far as I'm aware, don't use Samsung chips but rather Hynix (not bad as well) or Elpida (those are a bit worse I think?).
my powercolor red dragon 470/4 will also do 28+. does 28.5-28.8 on eth with 1750 straps @ 1300/2100 -75mv -i 8. runs 24/7 with no problems. about a month ago it could hit the low 29s, guess the epoch increase slowed it down a touch.
seems to be a samsung thing?