I get that 20 years ago hard drives weren't the quickest and there was a limited choice in codecs so it made sense to playback from RAM. But now we all have SSDs and DNxHR exists I don't get why AE has not been re-written to playback straight from a hard drive rather than moving it into RAM first. It would be great for AE to playback from disk with a choice of codec and bit depth dependent on a users needs and system capability, much in the way that Resolve does with smart cache (see pic). Uncompressed I gather would be a strain on most systems but this is overkill anyway, certainly for playback - I challenge anyone to point out any differences between uncompressed and DNxHR HQ and if people wanted to keep working uncompressed then the option could always be there to playback from RAM but for me and I would assume many others 10bit DNx would be fine. This will mean longer timelines and smoother playback as AE isn't having to move disk cache to RAM for stuff further up the timeline when playing back.