Antminer L3+ cgminer-stats and default diff

[Mr_Snipes]

When i looked at the stats of my miner, some questions came up. Googleing them has brought mixed results so i assume i need to look at my cgminer-stats in context of it being an ASIC-miner.
Some wrote for instance that discarded shares with gpu-mining are caused by too low power. I doubt that my asic doesn't get enough power.

How is the best difficulty-setting determined ? The minimum diff can be specified via the password-parameter in some pools.
Also i am seeing 51.000 accepted shares vs 83.000 discarded shares. Something to worry ?


This is how it looks like atm:
Status    Diff    GetWorks    Priority    Accepted      Nonce#    DiffA#       DiffR#    DiffS#      Rejected    Discarded    Stale         LSDiff                    LSTime
alive           49.2K     167        0              1,269                 224,435      57,430,016  52,224        0                        4               4,061        0      49,152                  0:00:35


On other pools like nh (that above is h2c) the discarded exceeds the accepted by far as well.