It's not really a new problem, in fact it's probably one of the oldest as far as computer hardware is concerned: the interconnections in our computers are often all too slow.Interconnections are everywhere; they send information between computers, between motherboard components, between the motherboard and CPU, and even in recent years between individual CPU components. Currently, the interconnection technology maxim can be summarised as, "bring lots of copper, son".
Unfortunately, this technology is limited by the laws of physics; signal loss dependent on the length of the bus, possible desynchronisation if the bus is too long, electromagnetic interference between the bus tracks... and this is only getting worse with the increasing frequency of buses. Eventually, their flow will no longer be able to increase any further.
However, Intel as ever has a solution to this difficult problem, and it is once again optical fibre that comes to the rescue. The prototype converts electrical signals to light and sends them over optical fibre using four lasers of four different colors. Upon arrival, the photons are converted to electrons to be used by the electronics, resulting in no electromagnetic interference.
This type of connection can already achieve a throughput of 50 gigabits a second, according to Intel, and could easily go up to 1 terabyte a second through a single fibre. Some such technologies already exist, but according to Intel they are too expensive and cumbersome to be used in personal computers. By using multiple colours and multiplexing the light signals, the fibre is able to operate at its maximum possible throughput.
And so the baby of Intel is born; Light Peak, a true bridge between the worlds of silicon and light. With this type of converter and a minimum of latency, the signal can travel at speeds of up to 10 gigabits a second. The potential benefits are obvious: on a motherboard, most of the space is used for connecting peripherals; the problem of clutter would be remedied somewhat by smaller connectors (as opposed to, for example, PCI-Express x16 slots). Between the processor and the motherboard, the connection would also benefit from simplification of the socket design. And what about inside the CPU? Why not make miniature versions of this system for them? Some years ago, IBM worked on a similar technology. The production of massively parallel processors was the price and the result of that endeavour.
For folders especially, Light Peak is a technology to keep an eye on. Applications in general are becoming much more multi-threaded in nature, and any technology which reduces synchronisation time between CPU cores and threads will be especially welcome in Folding@home.
The subject is so vast and promising that Intel has made a very catchy little video to introduce the principle of fibre optic communications, as well as some possible applications.
Source: PC Inpact (in French)
KaySL
On: 09/05/10
