SteveRo, what is your PCmark Vantage HDD total score with those 4? 56.000 like the ORB window in the back says?
And have you tried them on ICH10R? You may get higher scores there.
And once again, your 1231ML seems to top out around 60K IOPS. 4x x25-V should be able to pass 100K, maybe even 120K.

I think Anvil is tinkering with stripe sizes on ICH10R from 4K-128K and PCMV HDD test, maybe we'll se some tables later.