WDM isn't too helpful in general except for long links, but fibre has been used inside large computers and data centers for yonks.
On-chip optics is the win. Turns out that you should be able to do communication faster (~c/4 for silicon photonics vs. ~c/10 for long lines with repeaters), and at lower power. I calculated that my antenna-coupled tunnel junction modulators would come in at about 60 uW/(Gb/s). (I didn't get them working, unfortunately.)
Cheers
Phil Hobbs
I was thinking about some rack size fiber loops with an add/drop interface at each box or actually a drop/add fiber system.
What is the practical performance in some passive drop/add box along the fiber loop ? Is it realistic to assume that the drop box will attenuate the loop signal enough that a new signal could be inserted into the loop ?
It limits your connectivity, and doesn't save that much space compared with point-to-point links.
Also fibre within racks is all 850 nm multimode (orange sleeve), whereas WDM is done at 1550 nm, single mode (yellow sleeve).
Cheers
Phil Hobbs
Use something like the TI or Max Video SerDes. One copper pair gets
Parallel was faster than serial, why isn't there an UPB - "Universal Parallel Bus"?
but
Because jitter, skew, and cost are bigger problems than bandwidth.
There was: ISA, and later PCI.
Given N wires or twisted pairs, each can carry a self-clocking data stream, and that's generally faster than using those same wires for parallel data.
That's why a PCI Express link with N pairs uses each lane for serial data.
Also consider IDE and SCSI bus.
delo
How many cable pair uses USB3-x?
It also means, if suitably implemented, the link can keep working when not all the wires are connecting.
NT
Yes. PCIe is (somewhat) adaptive to the number of functional pairs. And any board from 1 to 16 lanes will work in a 1-lane socket.
and afaiu many motherboard also support splitting the pairs between boards so you can have two 8 lane cards in a 16 lane socket
I got a 50 pin SCSI CD CHANGER that fits in a standard bay. How'd you like to have to design that ? (especially the LASER which obviously has to pass through all the holes in the disks under the one being read, s*it, usually they can't focus if the spindle height is only about 1mm from where it belo ngs, usually caused by someone putting more than one disk in at the same ti me)
I just realized how old this thread is...
But now that I think of it, what about firewire ? It was supposed to be "all that" but seems to have gone the way of the betamax.
Billions, and they're shipping more all the time. :)
Oh, did you want to know how many cable pairs in one USB3 cable? :P
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