The 4930k have the IHS soldered (heat exchange almost perfect) I'm not sure about the E5-1607 I guess it's soldered, since it's the first series, even though I've never owned this model.
Wow I've never seen a 4930k stay at 50°C with all six cores fully loaded (x36 x36 x37 x37 x37 x39) on intel heatsink... and as far I remember it takes about ~1.250V or more at stock settings.
So there is something wrong here, or something you're not telling me, I've built a few of them back in time with AIO water cooling, no way.
But again, there are many things to be considered; ambient temperature, case & fan configuration, workloads, and so on.
Well as I said, if it is enough for your needs, and it keeps the temperatures within the limits, nobody...