Rx 470 Asus Strix OC 4Gb 250 H/s stock, Overclock 270 H/S

HARDWARE - 2 x RX470 / ASUS STRIX OC
HASHRATE - 270.159 M /CLAYMORE 12.2 / W10 X64
CONSUMPTION - 170W
TEMP - 60º

OVER 1270 Mhz / MODDED FAN SPEED Software Asus


CLAYMORE CONFIG.

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

ZecMiner64.exe -zpool zec-us1.dwarfpool.com:3336 -zwal  Wallet -zpsw *@gmail.com -r 0 -mport -8082 -i 8,8

I have a problem my Miner indicates that I am generating 440H / s but the pool says that only 300H / s and it happens to me with Claymore's ZCash AMD GPU Miner v10.0 instead with version 9.3 it indicates 420H / s and the pool says 420 H / s , it's wrong ?