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A single 4k/60p/24bit display requires 1.5GB/sec, about 10-15% of your PCIe readback bandwidth. Since it has to be both written to and read back out of main me
by jamesfmilne 10y ago
A single 4k/60p/24bit display requires 1.5GB/sec, about 10-15% of your PCIe readback bandwidth.
Since it has to be both written to and read back out of main memory, that's 3GB/sec, which is between 5-10% of your CPUs memory bandwidth.
It's OK for 1080p res but falls down at higher res.
Apple don't do this on their laptops either, and still employ a gmux to switch between integrated and discrete graphics for the laptop display (although that's mainly for power-saving).