So Long HDMI: New Standard for A/V Uses Ethernet Cables
- Thread starter Unknown Soldier
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Yep. It's basically a chipset that transports DisplayPort protocol and PCI Express protocol. Apple implementation seems to be a 10 GigE x 2 electrical, but over time they are expecting speeds of up to 100 GigE as optical transceivers become cheaper. They plan on putting the transceivers in the actual cables, which seems like it will just end up making incredibly expensive cables. Plus, you can 10GigE transceivers in an SFP+ form factor now, but they require heatsinks. 40GigE and 100GigE are in CFP form factors, which are HUGE. It'll be quite a while before they can make those small enough to put one at each end of the cable.
Well, as mentioned, the full capacity is 20Gbit/s full duplex, so it's not a downgrade, but rather a slight upgrade really (not sure about cable length; I read 17gbit/s displayport had a cap on cable at 3 meters), but even if it was "only" 10Gbit/s, how many people would you really expect to max that out?
It'd be a tiny subset of computer users who would be limited by that amount of bandwidth. "Only" 10Gbit/s is far more than standard single-link DVI, which is what most people manage just fine with.
Nice, if computers should ever need to receive 10Gbit/s from monitors.
Until then it is 10Gbit/s when compared to DP.
Cheers
I don't think one channel is 10Gbit/s up and the other is 10Gbit/s down. Each channel is 10Gbit/s full-duplex. So you can do 10Gbit/s up on each channel at the same time. 20Gbit/s up and down, concurrently.
Yea well, this cable is able to carry PCIe also, so you wouldn't hook it up just to monitors. Back when lightpeak was first presented it was touted as a replacement for EVERYTHING in use right now. I wonder what happened to that. Cost, probably, because this stuff's way more radical than what you need to hook up most USB devices, but networking would be a good replacement. Hooking up PCs and routers/switches and be able to pump massive amounts of data through the connections at a cheap cost... Imba!
No, as has been stated repeatedly, it's 20, up AND down. Concurrently. Pretty crazy, I know. Not sure how many wires they use to transmit over, it's undoubtedly differential twisted pairs like in pretty much all recentish connection standards, but if each link consisted of just one differential pair (per direction, obviously) it'd be pretty crazy.
Silent_Buddha
Legend
It appears to be a bit different from DP in that it's 2x10 Gbps bidirectional cables with each cable specifically purposed to a specified task.
Intel in their presentation explicitly mentions up to 2 high resolution (1920x1200) displays can be daisychained (fits the 10 Gbps) and up to 7 devices total.
It appears that 1x 10 Gbps cable is reserved for video while 1x10 Gbps cable is reserved for everything else.
Their diagrams also imply this is how things work as it shows 1x display cable and 1x PCIE device cable.
3m limit for both currently. Thunderport is limited to 3 meters when using copper cable (the only type available for launch) and "10s of meters" once optical cables are introduced.
Regards,
SB
I don't see what gave you that impression. It's certainly never been stated in any of the text I've seen.
The Intel diagrams don't show PCIe and DP traffic separated. Quite the opposite they appear merged into a single stream in all the PR images shown off on places like Anandtech and so on.
Yeah, that would make sense, in view of current DP cable limitations... I suppose they didn't feel like going with coaxial cables for all the signal leads.
Since the cable also alledgedly carries 10W of power, I wonder how thick it's going to be... Probably 12V power then like firewire uses, to cut down the amps.Silent_Buddha
Legend
Well, a lot of things. Intel themselves appear to limit daisy chaining of displays to 2x monitors. Anandtech is the only site I've run across that has mentioned 20 Gbps. All others, including Intel mention 10 Gbps. And that there are 2 channels.
Intel are very very careful to never mention 20 Gbps in any of the material I've seen. It's always 10 Gbps per Port.
http://www.intel.com/technology/io/thunderbolt/index.htm
That's the page they put up on the 23/02/2011. You'll notice they only ever reference 10 Gbps performance never 20 Gbps implying that the bandwidth is not combined in any way. If it was capable of providing 20 Gbps aggregate bandwidth to a device, I would imagine they would have mentioned it as that is certainly something to boast about.
Regards,
SB
Well I'm still not convinced. Look here: http://www.anandtech.com/show/4194/intels-codename-lightpeak-launches-as-thunderbolt
Scroll down to the Thunderbolt Technology Architecture slide and look at the stack. Second layer from the top... Common Transport Layer, it says. Not sure how common separate channels for video and other data can be. Besides, why would they do that, they gotta merge everything anyway by neccessity when they move to optical so if they can do it then then they can do it now also.
Doesn't make sense!
Scroll down to the Thunderbolt Technology Architecture slide and look at the stack. Second layer from the top... Common Transport Layer, it says. Not sure how common separate channels for video and other data can be. Besides, why would they do that, they gotta merge everything anyway by neccessity when they move to optical so if they can do it then then they can do it now also.
Doesn't make sense!
The word I keep seeing is 'multiplexing' of PCI Express and DisplayPort, so that, to me, suggests it will transport both protocols on the same link. As Grall said, when they move to optical, they'll have one pipe up and one pipe down, unless they put two transceivers at each end, which would be even more ridiculous. Although, looking closer it does say it supports DisplayPort 1.1a, which is less than 10Gbit/s. DisplayPort 1.2 is much higher bandwidth.
They say Thunderbolt is a switch fabric with QoS functionality. So basically it's sort of like a layer 2 switch for PCI Express and DisplayPort. It seems each of the two bidirectional links can support both protocols, because you can have to displays, or no displays and a bunch of PCI Express devices. Looks like Silent_buddha may be right, and it can't bond the two links to achieve a usable 20 Gbit/s for a single super-high resolution display.
Even if it can't, I still think this is a pretty useful port. I just don't understand why they'd make a port that couldn't support their own standalone displays.
They say Thunderbolt is a switch fabric with QoS functionality. So basically it's sort of like a layer 2 switch for PCI Express and DisplayPort. It seems each of the two bidirectional links can support both protocols, because you can have to displays, or no displays and a bunch of PCI Express devices. Looks like Silent_buddha may be right, and it can't bond the two links to achieve a usable 20 Gbit/s for a single super-high resolution display.
Even if it can't, I still think this is a pretty useful port. I just don't understand why they'd make a port that couldn't support their own standalone displays.
iFixit, which has published yet another teardown of the latest Apple hardware, suggests that current thunderbolt standard is indeed one link dedicated to each protocol. Bit of a bummer I must say. Lightpeak looked like a totally sweet concept, replacing everything but power with one connector. This is pretty half-assed really. Only supporting PCIe - which currently is not an external connector, and not SATA which IS an external connector right now - and a crappier version of displayport than the most current on a bog-standard copper wire connector. This will lead to connector confusion down the road.
Feels rushed. I can't help thinking Intel should have let this one slow-cook a bit more until it was fully ready in an optical version. Perhaps they wanted it out now, fast, to try and choke baby USB3 in its cradle, I dunno, but if so why does their own sandy bridge platform controller hub support USB3 but not TB?
Blazkowicz
Legend
USB3 is supported? I thought it was in the eternal "not in the southbridge" status.
sure it looks like "Thunderbolt 0.9" and is thus quite confusing. But putting aside the displayport confusion I feel great potential. 10 gigabit point-to-point networking on the cheap!
You may build a NAS/SAN box with a raid 10 (i.e. cheap PC with linux or freeBSD and Free iSCSI software) and run a bad ass (but still cheap) diskless gaming PC/workstation/VM workhorse with disk access as fast as local, in the > 200MB/s range.
If they are shortcomings from an early version, it's still better than firewire 3200, as it's not vaporware.
rather than buying an overpriced Intel motherboard or MacBook you might stick a thunderbolt PCIe 4x board in an empty PCIe 16x slot.
I do not feel too bad about the display port confusion (still running VGA displays). you actually have the option of an external graphics card if you need display extension, for showing off movies and powerpoints on a projector for instance. that may be no more expensive than bloody display port adapters (in situations you need an active one).
sure it looks like "Thunderbolt 0.9" and is thus quite confusing. But putting aside the displayport confusion I feel great potential. 10 gigabit point-to-point networking on the cheap!
You may build a NAS/SAN box with a raid 10 (i.e. cheap PC with linux or freeBSD and Free iSCSI software) and run a bad ass (but still cheap) diskless gaming PC/workstation/VM workhorse with disk access as fast as local, in the > 200MB/s range.
If they are shortcomings from an early version, it's still better than firewire 3200, as it's not vaporware.
rather than buying an overpriced Intel motherboard or MacBook you might stick a thunderbolt PCIe 4x board in an empty PCIe 16x slot.
I do not feel too bad about the display port confusion (still running VGA displays). you actually have the option of an external graphics card if you need display extension, for showing off movies and powerpoints on a projector for instance. that may be no more expensive than bloody display port adapters (in situations you need an active one).
With the anemic cable length it doesn't really make much sense for SAN. Really our ability to get cheap network bandwidth is constrained by artificial market segmentation rather than inherent cost ... as HDMI shows, 10 Gb/s can easily be done cheaply, with cheap long cables.
I'd certainly prefer a 6 channel 3.4 Gb/s per channel LDVS connection over Thunderbolt ... with ethernet as the transport protocol, with automatic trunking of channels and RDMA support in the controller. The rest we can do in software.
I'd certainly prefer a 6 channel 3.4 Gb/s per channel LDVS connection over Thunderbolt ... with ethernet as the transport protocol, with automatic trunking of channels and RDMA support in the controller. The rest we can do in software.
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