What GPU are you using? cause some of them use Overclock setting as stock, and care to post your miner .bat settings so I could see what you have set, cause I believe there are some stability commands to type in depending on your card.
Here are my settings and afterburner setting. by the way I have also edited the bios.
4 Asus RX480 4gb
.bat settings
setx GPU_FORCE_64BIT_PTR 1
setx GPU_MAX_HEAP_SIZE 100
setx GPU_USE_SYNC_OBJECTS 1
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_SINGLE_ALLOC_PERCENT 100
EthDcrMiner64.exe -epool eth-eu1.nanopool.org:9999 -ewal ---------------------------------------- -epsw x -etht 1000 -mode 1 -ftime 10
Im no expert on these things,but here are some things you could play around with to see if you get more stability.
- Try updating your drivers to a more recent version.
- As a few people said above, your friend has found a stable clock settings, so you could try using the standard clock and increase it till you hit your desired hashrate/stability.
- Make sure it's using asm algorithm and you could try controlling your speeds with -dcri command.
- And the last thing I could think of is sometimes you can get instability issues from incorrectly installed or poorly modified bios. You could use this guide to flash them properly: http://1stminingrig.com/best-bios-rom-sapphire-nitro-rx-480-8gb-oc-mine-ethereum-30-mhs/