Re: Optical?
On the horizon, as far as technology is concerned, means that it takes at least 7-10 years for something that is being demonstrated now to make it into a commercial product. And I think that you will not get optical interconnects between (optical) chips on a board until you can lay down an optical path on a multi-layer board. If you have to have optical cables connecting everything, the computing density will go down significantly, and be a major maintenance problem.
As an aside, the P7 775 systems will have been in use for forecasting for about 3 years at the Met Office when they get turned off next year. At that rate, they will have gone through at least one further generation of HPC beyond what is being announced today before there is any chance of optical chips coming along.
As a second aside, the interconnect of the existing P7 775 systems is already mostly optical, but there are electrical to optical transceivers attached directly to the Torrent hub, with fibre running to the backplane. Inside each drawer, it's mostly electrical. From drawer to drawer is optical. The back of the Cray systems appear to have lots of orange cables (the colour normally associated with optics) as well.
Biting the hand that feeds IT
