I have heard that coolers for that GTX 970/980/TitanX will work on the M40 at the same time.  One of the EVGA HYBRID coolers (water cooling for that GPU, air for the memory) might be fascinating to try.Removed the M4000 in the x16 slot (my P400 is useful for the OS on the x8) and plugged in the x1 riser, linked "USB" cable towards the riser as wel