CRTCs vs. outputs
Posted Jan 23, 2007 13:25 UTC (Tue) by daenzer
(✭ supporter ✭
Parent article: LCA: Updates on the X Window System
There's some confusion between CRTCs and outputs. A CRTC scans out the pixel data from memory and converts it into a serial signal. Several outputs can pick up this signal, process it, and send it to an output device. But they can't display anything the CRTC didn't scan out in the first place, so the number of independent viewports is essentially limited by the number of CRTCs, not outputs. Most current popular GPUs (such as that in Keith's laptop) have two CRTCs.
Nice article though.
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