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by maggit 5591 days ago
The bandwidth is apparently entirely unimpressive. DisplayPort is currently at 17.28 Gbps, so Thunderbolt can push ... 0.6 monitors? ;) (In the worst case, at least)

I have been excited about Light Peak/Thunderbolt for a year or so now, but in that time it seems the ambitions have become smaller, and the competition has developed as well.
3 comments
onedognight 5591 days ago
It has two independent 10Gbps channels, so it can do 20Gbps.
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maggit 5591 days ago
That's not really relevant as long as you can't choose the directions for the channels. You are only going to get one channel in each direction.

Edit: Whoa. I just re-read parts of the Intel documentation, and it seems there are indeed two independent downstream channels. My bad. It also looks like there is no provision for using both channels for a single device? I have no idea.

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GHFigs 5591 days ago
2x10Gbps is still enough to drive two 2560x1600 displays at 60Hz, which is all the prior DisplayPort implementation could do.
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wtallis 5591 days ago
Check out the Wikipedia page for DisplayPort, as it has a good explanation of the bandwidth requirements for video.

It lists 2560x1600x30bpp @ 60Hz as using just over 8Gbps, so any one consumer monitor will work fine over Thunderbolt.

The 17.28Gbps speed would only be needed for multiple monitors or a high-resolution, high-color-depth, high-refresh or 3D monitor. Thunderbolt and full-speed DisplayPort both have enough aggregate bandwidth for four 1080p streams.

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hop 5591 days ago
Well possibly, if it's in displayport mode using all four lanes in one direction, it can push that much bandwidth. How much bandwidth does a 27" apple display use?
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TillE 5591 days ago
Well, let's see:

2560 x 1440 resolution at 24 bits per pixel = 88,473,600 bits

At 60Hz, that's 5,308,416,000 bits per second. So a little more than half the claimed 10Gbit bandwidth of Thunderbolt. I guess you're not going to be running two of them on the same port.

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rapind 5591 days ago
Depends on what you're using it for I guess. For my typical day coding / web browsing / etc. I'd rather run two at 16bit instead of one at 24bit.

If I was editing movies it'd be a different story.

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