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Comment by jotm | Hacker News Reader

I'm not knowledgeable in this area, but isn't Thunderbolt a more direct interface (since it's basically external PCI-E) with less overhead than USB, making it a better choice for devices requiring low latency (audio interfaces, graphics cards, SSDs, etc.)?

Regardless, I believe Intel's Thunderbolt is here to stay, along with USB 3.x...

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Correct, although I would also mention high-end video; probably the killer app for Thunderbolt. As you said, audio interfaces are a big one, particularly at the high-end, where high throughput is desirable but low latency is essential. As for graphics cards; it is really a general expandability solution, which is much simpler for less-technical users than opening up a PC and attempting to install an expansion card. The new Mac Pro design seems to follow this line of thinking.

Thunderbolt will always be a more niche market than USB, but I could see it having an even longer life than FireWire (which is still popular for high-end video and audio applications).

Speaking of the Mac Pro, I was wondering whether the 6 TB2 ports are independent and more importantly, could they be aggregated (like for external SLI or Crossfire)? That would be really interesting...

Having never tried to program a thunderbolt bus driver, but knowing that writing USB packet control code as being the biggest pain in the ass because the entire standard is a hodge podge mess, I wonder if Thunderbolt is easy to implement connectors for.

Really though, the problem is like most licensed Intel tech they charge out the ass for licenses. They heavily jack up Intel CPUs and Thunderbolt to subsidize their huge R&D budget.

Thunderbolt is just a long distance version of PCI Express, so existing PCIe device drivers should work just fine.

This sounds very interesting. I guess the only reason there has been no adoption of thunderbolt is just the silly license rent seeking Intel tries to pull on the interface, a lot like firewire.

Licensing fees have nothing to do with it. The reason is that Thunderbolt is expensive to manufacture, and mass-market computers have tiny profit margins.

Adoption is starting. Newegg lists a variety of Thunderbolt gadgets. Mostly it seems to be storage products, where 10 Gbps Ethernet is needed but makes Thunderbolt look cheap.

How do you consider the USB standard a mess? I am quite impressed with it as a low-cost peripheral port that requires minimal hardware resources. I agree, it can be a pain to write for. My biggest difficulty was crafting HID descriptors! Yikes!

Have you ever tried to push more than 6 keys on your keyboard? e.g. in local two-player games.

Modern gaming motherboards come with a PS/2 port for a reason...

Modern gaming keyboards come w/ full n-key rollover over USB. My Noppoo Choc Mini is capable of full NKRO whereas my Model M can't do the same over PS/2.

USB doesn't impose a simultaneous key press limit that low, the keyboard does. The 'Report count' field of the 'Key codes' usage page of the keyboard's USB endpoint descriptor determines the maximum number of simultaneous key presses. This field is a byte, so it could be up to 255.

The keyboard endpoint example in the USB HID spec does have 'Report count' set to 6.

Greg Kroah Hartman wrote about implementing Thunderbolt for Linux: http://www.kroah.com/log/linux/hardware.html (not a pretty story)

I suspect Intel has realised that people who need Thunderbolt have no practical alternative. May as well charge what that market will bear for a while.

AMD does have a low cost alternative - Lightening Bolt http://en.wikipedia.org/wiki/Lightning_Bolt_(interface) - and I will admit that if it takes off and beats Intel/Thunderbolt I will smile a bit. It will be AMD64 all over again.

I'm curious as to how the hell Intel can charge huge license fees on a pci express passthrough port. Though, it doesn't sound like Lightning Bolt is similar - the Displayport part, maybe, but USB is serial and has high latency compared to the pcie bridge.

> I'm curious as to how the hell Intel can charge huge license fees on a pci express passthrough port.

They aren't - they charge the fees for Thunderbolt. You can't claim something supports Thunderbolt without paying licensing fees.

> it doesn't sound like Lightning Bolt is similar

You can draw a venn diagram and find that all three have an overlap. A desire for fewer cables, to be able to connect lots of stuff, and bang for the buck. Display, storage, peripherals etc. Outside of the venn diagram, Thunderbolt does have low latency, but most don't need or want to pay for it. If Thunderbolt support was as pervasive and cheap as USB, it would be a different conversation.

I agree. I have a hard time seeing thunderbolt dying because of USB 3. People said FireWire would die when USB 2 came out, but it's still with us (never nearly as popular, but still there).

I just wish the USB people would get a brain about naming. Full Speed? High Speed? Super Speed? Super Speed Plus? The numbers work fine, and don't confuse the hell out of consumers.

I guess that's why we shouldn't use them.

Some folks I know working on the technical side refer to this iteration as Ludicrous Speed seeing as the naming has gotten so convoluted.

Anyone knows how far this 'basically external PCIe' actually goes? If it's really PCIe, does this mean I can get any of my current PCIe cards, solder a TB cable onto them and use them as such provided I have proper drivers?

Yeah. There exist dead expensive adapter boxes and AFAIR they only get either 4x or 8x speed, but not all 16 PCIe lanes.

Here's a guy connecting a graphics card to his mac via Thunderbolt.

http://hexus.net/tech/news/graphics/58429-macbook-air-uses-g...

    "Normal" GPU + external Powersupply
     |
     |
   Adapter: PCIx1-Slot to Express-Card
     |
     |
   Adapter: External Expresscard-Slot to Thunderbolt
     |
     | <-- TBolt cable
     |
   MacBook

nice.

> but isn't Thunderbolt ... a better choice for ... audio interfaces

I certainly see your point and am in no way disagreeing with you, but this made me laugh.

May I know why? I've used USB and Firewire interfaces, and while both sucked at driver support (plus Firewire is pretty bad on PCs in general), the latter was much better, especially for live work...

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