Why the difference between GH/S(ideal) and GH/S(RT)?

[Morescratch]

I have some S9's that where ideal is higher than RT and some where RT is higher than ideal. Is that normal? In the cases where RT(Real-Time???) is higher than ideal does that mean it's running overclocked?

[Philopolymath]

Yes it is absolutely NORMAL...
The miner firmware tries to find the best frequency that will give approx the "Ideal" hashrate. (For best performance re: temps and errors etc..)
That's what it is doing when you first fire it up or restart/reboot it.  It first runs/ tests freq's for each board.

The "Real time" is the actual results..which WILL FLUCTUATE.... but usually not dramatically say 5% or so...