Fiber On Your Motherboard...Soon!

km790816 writes: "In this post I joked about wanting an optical bus on my PC. In the last week I've seen two articles from The Register and EETimes discussing the real possibility. Both mention high bandwidth and lower heat and power usage. Sounds good to me."

Comments

Cool, people finally starting to publish

[bstrahm]

I love hearing that people are finally starting to publish intentions. I have been hearing rumors about this for a year or so now, since an EVP where I worked started talking about plugging a Fibre into the side of the microprocessor (and he wanted to own that connection)
As is normal, he missed completely thinking it would be a 10GbE fiber for networking, rather than a 40+GB connection to main memory...

The comments on working on the I/O side of the processor were right on (I read the EETimes article, rather than the Register article to get "real" facts ). For years Sun was known for having the slowest RISC processor in the business, however they had the fastest boxes. No one seemed to understand this, until they realized that they were running multiple 128 bit memory buses at rather good clock rates. That was better than 10 years ago, and just now we are starting to see memory busses approaching this level in their competitors hardware.

Re:First post on this one

[Water Paradox]

Of course it will have a 20 second "Slow Down, Cowboy!" timer. That's how long it will take to boot XP 2002. Linux will, of course, boot in .3 seconds on that motherboard.

From the article: "But it may not take divine intervention to get more mileage out of copper interconnect. Intel claims it can reach speeds of 10 GHz and beyond in five to eight years using copper. "We're confident we can get to 10 GHz. And there's reason to believe we can double that," Pinfold said."

I'd put my money on copper; we're still using
gasoline, when hydrogen-powered cars have
been viable for years.

http://www.auto.com/industry/iwirn22_20010822.ht m

-wp

Fiber vs. Fibre

[crow]

It is important to note that this is really about fiber, not fibre. So it really is about optics, not the fibre channel storage interface.

For reference, fibre channel is a high end storage interconnect which is replacing SCSI in corporate data centers. While fibre channel was designed with optical transport in mind, it also runs over copper. While I would not be surprised to hear about high-end server motherboards with fibre channel on the motherboard (instead of IDE or SCSI), that would be a far less interesting story than having actual optical transmission on the motherboard.

Cool.

Re:Not a troll

[RollingThunder]

While most folks are correct in that the biggest latency source is the drives right now, there is a fair bottleneck on the RAM to CPU bus. I think it's up around a 8:1 ratio right now (4:1 if you have a 266 MHz FSB), which means that your CPU can spend a large portion of its time waiting for data from memory.

True, that's what the L1 and L2 cache are supposed to prevent, but some apps (games, mostly) blow through that cache without even thinking about it. WWIIOnline, for instance, gets bitchy with only 256MB. It's only happy once you have 512MB. How long will even a 4 MB on-die cache last?

If we can increase the speed that we can toss bits between the CPU and RAM, we'll reduce one more sticking point (and RDRAM, expensive as it is, was meant to do that), and higher framerates for all! :)

Free space optical busses

[maggard]

There's been some interesting discussion recently about shifting data transmission off of electrical busses within computers.

The idea is that subsystems could communicate within a computer chassis entirely by light across open space or reflected off of the interior of the chassis. Instead of the complex process of wiring hundreds of chip leads down into packaging all of the data would be sent off and on the chip by tiny lasers & receivers, all built into the chip itself during fabrication. Through a window on the chip case and the CPU could "see" the RAM controller, perhaps even the RAM directly, the graphics controller, the high-speed IO subsystems, etc.

Card edge connectors would still be used for electrical supply and some signaling but it'd be relegated to slow-speed stuff. This would greatly simplify motherboard design as well as chip packaging. Of course this would come with it's own problem: Dust would be a showstopper. Reflections - their propagation and interference properties would become issues. The signaling systems might require an uneconomical transistor count on the chips. Overclockers would obsess about albedo and air filters.

I'm trying to find some good links for this but not finding any - anyone else come across any good discussion on this recently?

Re:Optical on the motherboard..

[maggard]

Also, Time magazine reported last year about this, and they pointed out that the kind of speed offered by fiber is the only real bottleneck to creating a truly self aware computer.

Oh please, that old canard about intelligence spontaniously arising out of sufficient processing power.

Throwing hardware at AI hasn't resulted in any fundamental breakthroughs and it isn't likely to. Oh it makes things happen more in scale with us and enables a lot larger cycle budget for increasingly lower-yield strategies but it's really just more of the same.

Self-organizing systems and emergent complexity happen due to underlying architecture. Life has had billons of years and the best incentive possible to evolve this - we're only now beginning to understand the subject.

Assembling a computer with the speed and density of a human brain won't mean it'll suddenly magically become self-aware, open it's IO and and engage us in conversation.

Serial communications & SCSI

[Klox]

I just wanted to address two types of comments I've seen posted here:

* Encoding / decoding speeds are done at the speed of the medium. Encoding and decoding optical signals doesn't have any more overhead than PCI or IDE. The spec. writers and endec designers are well aware of these issues. That's why technologies like 10Gb Fibre Channel or Eithernet aren't ready yet -- not because we can't transmit at that speed, but that we can't build an entire NIC to sustain those speeds. (Give us some time: we'll be there soon enough.)

* Serial interfaces like Fibre Channel and Infiniband (and even Gigabit Eithernet) aren't replacing SCSI. They are replacing what you think of as SCSI: the 50 or 68-pin cable in your case. But SCSI is the protocol being used to talk to all those FC & Gig-E storage devices. SCSI over FC is called FCP (see T11's specs for more on FC). For Gig-E, most companies are looking into iSCSI, iFCP or FCIP (SCSI over IP or SCSI over FC over IP) for SAN-to-SAN communications. I forget the name of the spec for SCSI over Infiniband, but it pretty much rips it's ideas from the above specs. (sorry, no links for Gig-E and Infiniband at the moment: start at T10 or The SCSI Trade Association)

BTW, I refer to "serial interfaces" above instead of "optical interfaces" because a lot of this is actually copper. Most likely, Infiniband on the motherboard will be copper and off the motherboard it will be optical. Most of the Fibre Channel equipment I have isn't "fibre" but copper.

Intel's serial obsession?

[MrResistor]

I've had serious doubts about the actual advantages of Intel's obsession with putting everything on high-clock serial busses, rather than lower-clock paralell busses that seem to provide the same bandwidth with less heat, interferance, and latency.

However, optical fiber would eliminate interferance, which seems to be the main barrier on clock speed. Heat would likely be reduced also, and cranking up the clock-speed would likely eliminate the latency issues. Not to mention the cool-factor inherent in optical.

What would be really cool would be to replace firewire and USB with fiber. There are hybrid fiber coax systems that could provide whatever power you're mouse/keyboard/etc would need, up to a certain point anyway. It probably wouldn't be enough to power an external drive.