Look at your hardware errors - compare # of submitted shares to the # of shares shown inside the pool stats - they will much, but you must fix your HW errors before you can expect your hash rate to match to your hashrate at the pool's stats.
Edit: what GPUs are you using, please consider increasing thread-concurrency to a higher #
I fixed the HW errors on GPU1 by decreasing intensity from 18 to 13.
GPU0 is a 7870xt with 15232 thread concurrency, GPU1 is a 7950 with 8192 thread concurrency. These are the optimum values that I have found by trying several different values.
- Bitmong
7950 (depending on the card) would need at least 14300 (from my experience), and 22400 for the best results with intensity of 18-20 (depending on the card). Anything lower then 14K would produce a lot of HW errors.
I have two 7950: and both of them are doing scrypt mining at 625-650Kh/s at 22400TC
You might run into errors if you you don't have enough system memory.
Edit: try fixing HW not with intensity decrease, but with some other setting (like TC), I have found that most cards for optimal speed would need at least 18 intensity