in afterburner Clocks for 3 middle cards 100-150mhz slower then end cards....
with any setting... anyclock settings or powerlimit.... all card cool 50-60c
but middle cards run cooler due to less clock?
Nvidia cards auto-overclock based on temperature/power%. The cooler the card is, the higher clocks it will hit regardless of over/under clocks that you may have manually set.
The middle 3 cards I am assuming get less airflow and so run hotter, so they clock lower. Nothing to worry about.