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A comment on Apple Silicon M1 chip in MacBook Air outperforms high-end 16-inch MacBook Pro. Parent comment

Re:Apple Silicon M1 chip in MacBook Air outperforms high-end... by simcop2387 on Wednesday November 11, 2020 @11:57PM (#25066601)
eGPU support will depend on if they have a way to work around the need for a PCIe I/O BAR. Many GPUs require that to initialize and as far as I know no ARM cpus support it since it's a legacy-ish x86 thing. It'll be the same problem that prevents gpu use on raspberry pi 4s still. I bet you can make a controller that'll provide a mapping for that to allow it but that'll mean needing a new enclosure (probably not a huge deal) and new silicon and drivers.
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Re:Apple Silicon M1 chip in MacBook Air outperforms high-end... by marcan_42 on Thursday November 12, 2020 @07:36AM (#25069145)
AMD GPUs do not require I/O BARs, and highly doubt Nvidia ones do either. The VBIOS will probably assume it can use it, but most modern cards can be initialized without actually running the VBIOS (because people use them on headless servers, for virtualization, and things like that). The I/O BAR is only required for legacy VGA compatibility, you can ignore it.
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Re:Apple Silicon M1 chip in MacBook Air outperforms high-end... by SXX on Thursday November 12, 2020 @05:16AM (#25068351)
AMD GPUs work just fine with POWER8 hardware so this is certainly solved.
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Re:Apple Silicon M1 chip in MacBook Air outperforms high-end... by dwaite on Thursday November 12, 2020 @02:37AM (#25067436)
I don't quite get how Apple could claim to be Thunderbolt-compatible with this sort of limitation in hardware, though.
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Re:Apple Silicon M1 chip in MacBook Air outperforms high-end... by djxfade on Thursday November 12, 2020 @03:59AM (#25067877)
It's not a limitation in hardware. It's a legacy feature of the x86 that isn't supported on ARM.

This could be solved by the GPU engineers by removing the legacy compatibility. "Nobody" boots a modern PC from BIOS anymore

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