Since then we've returned the KHX11000 to Kingston and had a number of conversations with the company's Tech bloke and the whole thing is something of a puzzle. It seems that the methodology we used was fine and dandy as the other memory all worked well enough but it also looks like the Kingston modules were fault free. Kingston tested the memory after it was returned and sent us these four screen grabs from CPU-Z that show the memory running at an effective speed of 1400MHz with an overclocked Core 2 Duo E6550.

Clearly this was something of a mystery so we asked Kingston to send another batch of KHX11000 DDR3 for us to have another go at.