5 ms·

I would think that the USB would be a major speed bottleneck and as such it would render the monitor connected to it practically useless, for even watching movi

I would think that the USB would be a major speed bottleneck and as such it would render the monitor connected to it practically useless, for even watching movies. EDIT: This is just my totally uninformed guess.

jacquesm 17y ago
> EDIT: This is just my totally uninformed guess. you are right, because you are wrong ;) : http://news.ycombinator.com/item?id=871408 http://news.ycombinator.com/item?id=871408
10ren 17y ago
USB 2.0 is 480 Mbit/s (max). I can't find any definite figures for video bandwidth, but I think it would be OK for youtube size, and probably for SD video. Note that since 3D acceleration is done inside the card, it isn't affected by the transfer rate - once it has the textures. Transferring the textures is what takes the bandwidth (assuming the USB card has 3D acceleration). But for command-line stuff, this delay would be undetectable, similar for reading text (like the Kindle, which has extremely low refresh rate), email, web-browing. Probably, most applications - certainly, most business applications - would be OK on it. But USB 3.0 will change all that. What's interesting is this may be a disruptive innovation, and the companies who got into while it was still niche are now set up (they know the technical problems, customer technical and business issues; and they have market presence, with end-user customers and retailers etc). That's how you win with a disruptive innovation. EDIT a review http://www.everythingusb.com/iogear_usb_2.0_external_video_card_12787.html http://www.everythingusb.com/iogear_usb_2.0_external_video_c...
- DarkShikari 17y ago
  I can't find any definite figures for video bandwidth, but I think it would be OK for youtube size, and probably for SD video For standard YV12 video, 1080p would be 1920x1080x12 bitsx24fps = 597 mbps. So you'd probably be good up to 720p at least, but not full HD (unless it's 1920x800, i.e. 1080p with letterboxing black bars cut off).
  - jacquesm 17y ago
    No, much less than that, after all you could keep a copy of the screen on the other side in a memory buffer and only do the updates on the differences across the cable.
    - DarkShikari 17y ago
      I was talking about video playback, not rendering a static screen.
      - jacquesm 17y ago
        Yes, well, you are the one that is working on a video codec, so you of all people should know that you can compress video for transmission across a link. Of course you're not going to transmit that stuff at full framerate uncompressed, that would be pretty silly.
- blasdel 17y ago
  It's nearly impossible to get anywhere near 480 Mbit/s out of USB2. Not only will you normally get maybe half that in ideal situations, you'll churn a ton of CPU pointlessly. USB's interrupt-driven nature is terrible for pretty much everything but Human Input Devices.

jacquesm 17y ago

> EDIT: This is just my totally uninformed guess. you are right, because you are wrong ;) : http://news.ycombinator.com/item?id=871408 http://news.ycombinator.com/item?id=871408

10ren 17y ago

USB 2.0 is 480 Mbit/s (max). I can't find any definite figures for video bandwidth, but I think it would be OK for youtube size, and probably for SD video. Note that since 3D acceleration is done inside the card, it isn't affected by the transfer rate - once it has the textures. Transferring the textures is what takes the bandwidth (assuming the USB card has 3D acceleration). But for command-line stuff, this delay would be undetectable, similar for reading text (like the Kindle, which has extremely low refresh rate), email, web-browing. Probably, most applications - certainly, most business applications - would be OK on it. But USB 3.0 will change all that. What's interesting is this may be a disruptive innovation, and the companies who got into while it was still niche are now set up (they know the technical problems, customer technical and business issues; and they have market presence, with end-user customers and retailers etc). That's how you win with a disruptive innovation. EDIT a review http://www.everythingusb.com/iogear_usb_2.0_external_video_card_12787.html http://www.everythingusb.com/iogear_usb_2.0_external_video_c...

DarkShikari 17y ago
I can't find any definite figures for video bandwidth, but I think it would be OK for youtube size, and probably for SD video For standard YV12 video, 1080p would be 1920x1080x12 bitsx24fps = 597 mbps. So you'd probably be good up to 720p at least, but not full HD (unless it's 1920x800, i.e. 1080p with letterboxing black bars cut off).
- jacquesm 17y ago
  No, much less than that, after all you could keep a copy of the screen on the other side in a memory buffer and only do the updates on the differences across the cable.
  - DarkShikari 17y ago
    I was talking about video playback, not rendering a static screen.
    - jacquesm 17y ago
      Yes, well, you are the one that is working on a video codec, so you of all people should know that you can compress video for transmission across a link. Of course you're not going to transmit that stuff at full framerate uncompressed, that would be pretty silly.
blasdel 17y ago
It's nearly impossible to get anywhere near 480 Mbit/s out of USB2. Not only will you normally get maybe half that in ideal situations, you'll churn a ton of CPU pointlessly. USB's interrupt-driven nature is terrible for pretty much everything but Human Input Devices.