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Comment by tl | Hacker News Reader

Well, you could buy a MacBook Air. Actually, I'd like to see an external GPU over Thunderbolt possibly built into the next line of cinema displays, which would remove the need for the GPU in the Pro line.

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Is the Thunderbolt bandwidth sufficient to run a modern GPU? AFAIK you'd only have one 10 gbit/s lane to use for it, and modern PCIe video cards use a lot more than that connecting directly to mainboards over multiple PCIe lanes...

Light Peak seems to have been sufficient for the Vaio Z.

> and modern PCIe video cards use a lot more than that connecting directly to mainboards over multiple PCIe lanes...

Forgive my lack of a source, but was there not an article (maybe on Anandtech?) about high-end cards being 90%+ as performant on a 4x PCI-e slot?

Yes. Thunderbolt bandwidth falls between a PCI-E 2.0 1x slot and 4x slot.

Tests that have been done comparing the performance of relatively high end desktop cards on 1x, 4x, 8x and 16x slots have established that while there is a performance penalty, such a solution would still out perform most mobile GPUs.

http://www.techpowerup.com/reviews/AMD/HD_5870_PCI-Express_S...

http://www.techpowerup.com/reviews/NVIDIA/GTX_480_PCI-Expres...

> which would remove the need for the GPU in the Pro line.

No it would not.

I think by "GPU", it's presumed to mean "non-embedded GPU" as Intel has taken to bundling it with their newer i series chips.

Naturally, it's in that context that I made my reply. I don't see how a laptop without any way to output data would even be considered.

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