ExtremeTech: "PCI Express Over Cable Opens Door For Modular PCs"

[Suhit Gupta]

<div class='os_post_top_link'><a href='http://www.extremetech.com/article2/0,1558,1585024,00.asp?kc=ETRSS02129TX1K0000532' target='_blank'>http://www.extremetech.com/article2/0,1558,1585024,00.asp?kc=ETRSS02129TX1K0000532</a><br /><br /></div>"Texas Instruments has successfully demonstrated running PCI Express over cabling reserved for Gigabit Ethernet, the first step toward a modular desktop PC. In a week's time, TI will begin sampling an unspecified PCI Express-to-PCI bridge chip, which will include the ability to transfer data over a Cat6 cable, TI executives said. Cat6 cables use four pairs of twisted copper wire, and is the cable usually chosen for Gigabit Ethernet connections.<br /><br />In the demonstration made Tuesday at the Windows Hardware Engineering Conference (WinHEC) show here, TI combined the PCI Express bridge chip with its own PCI7621 I/O controller that interfaces to smart cards, IEEE 1394, CardBus, and other small form factor flash cards. The chip routed a x1 PCI Express channel over the cable. By separating the I/O from the computing element, TI's new chip could transform the way desktop PCs are designed."<br /><br />This is an interesting attempt at separating processing and interface elements. So basically instead of a single chassis that contains all the components of the PC, this article claims that we could instead be moving towards a setup where we have different modules (processing, video, I/O, etc) all communicating over the high speed bridge. Replacements and upgrades would become so easy and more cost effective. Interesting idea.

[Felix Torres]

The big gains here are in video.
Cause high-end graphics are reaching the point where power consumption and heat load are exceeding what can be reasonaly packaged in an add-in card.

With PCI-express over CAT6, the video system can be a separate box with its own power and cooling and be cheaper than it would be if it had to be shoe-horned into an add-in card.

Plus adding extra displays becomes just a function of adding more video boxes.

This is big news on the CAD/CAM side and with likely polish off the last of the proprietary Graphics workstations.

On the multimedia side, it'll do away with breakout boxes.

I can see the guys at NVIDIA sighing in relief. ;-)

[Jason Dunn]

Felix nailed it - it will hopefully make upgrading components much easier. It will require a serious re-design of computer cases and cabling but the long-term benefits of this are extremely cool...assuming it picks up the necessary support.

[Felix Torres]

It will require a serious re-design of computer cases and cabling but the long-term benefits of this are extremely cool...assuming it picks up the necessary support.

Uh, not exactly.

The fun part is TI demonstrated it over regular Gigabit Cat6 cable.
No fancy cables are needed.

Implementation would be as simple as building an ATI All-Wonder Video *BOX* that attached via cat6 cable to a PCI Express card implementing the TI interface logic.

Think of this as a SCSI or Firewire adapter that can handle video cards, not just hard drives or digicams. :-)

You don't *need* buy-in from motherboard or chipset vendors.
Any old late '04 mobo will do. :-)

Ideally, you'd *want* the sockets for the cable on the Motherboard but they don't *have* to be.

[Jason Dunn]

The fun part is TI demonstrated it over regular Gigabit Cat6 cable. No fancy cables are needed.

Ah, right. I was thinking more of the speculation towards a cartridge-based system, which WOULD require a new breed of computers, but be super fun. :-)

[Tim Williamson]

Is PCI Express throughput greater than AGP?

[Felix Torres]

The fun part is TI demonstrated it over regular Gigabit Cat6 cable. No fancy cables are needed.

Ah, right. I was thinking more of the speculation towards a cartridge-based system, which WOULD require a new breed of computers, but be super fun. :-)

Fun would be slotless systems that can be assembled in slices; a CPU slice; a storage slice; a video slice; an audio slice...

Kinda like the old stereo racks...

Or how about a universal laptop expansion chasis, kinda like the old TI/99 expansion cage...

This could also be big on blade servers.

A very useful tech.
Now to see if anybody uses it...

[Felix Torres]

Is PCI Express throughput greater than AGP?

Ah, yup!

Bus Throughput

PCI 133 MBps
AGP 266 MBps
PCI Express 200/250 MBps each way, per pin.

So figure a minimum of 400 MB per sec, per pin.

PCI express channels run from 1 pin to 16 pins.

"Intel's Grantsdale chipset provides an X16 link for graphics, some 4 Gigabytes per second in each direction (8GB/s concurrent bandwidth) dedicated to graphics, over double the bandwidth offered by AGP 8X."

For more details, try:

http://www.anandtech.com/systems/showdoc.html?i=1830

[Suhit Gupta]

Announcement over at Blue's News that is related to this topic - Alienware makes their big E3 announcements; X2, an upcoming PCI-Express motherboard, and Video Array, a way of using multiple video cards in parallel, saying: "The Alienware Video Array and X2 motherboard will debut in Q3/Q4, exclusively through Alienware’s new ALX brand, a family of extreme performance systems catering to the demands of the most hardcore PC enthusiasts. ALX systems will be sold only in the United States, directly through www.alienware.com/alx or 1-800-ALIENWARE."

Suhit

[Tim Williamson]

Sweet, I think this componetized version of PC's could really be the next big thing in the PC industry.

This would truly be ideal for novice computer users who won't open a box to do an upgrade, it will create a broader base of people who are willing to upgrade components, and this will make the PC component companies happy since it'll be easier to sell component.

But I wouldn't mind a PC where you don't even have to open it up to upgrade, just pop that nifty new Nvidia Radeon 980,000 graphics cartridge in and you're good to go! :D