I just watched their "Samsung Unpacked" video, my teeth are gritting.
For example, "The AI makes the latency 9ms, said Token, while reading the autocue. It predicts where the pen will be and coupled to the new 120hz refresh rate makes the pen more responsive, blah blah blah..."
No, the tablet can track the pen, and even 30hz would look smooth if you tracked it properly. Android does everything with bitmaps, so every view has a bitmap it renders into, and these are composited into a single bitmap on the screen. Bitmap is blitted onto bitmap, sometimes hundreds deep, stacking them up into a single bitmap that is rendered onto the screen. Gigabytes of bitmaps are composited on the screen 50 times a second as you move the pen. Of course the hardware cannot do that and it slows down, so it can refresh 10 or 5 times a second. The redraw does not keep up with the pen. Tracking the pen is trivial, updating the screen to reflect where the pen moves is extremely difficult in Android.
Worse the redraw is single threaded, all of this compositing is done on the one thread on the one core.
The fix is to only update the tiny rectangles changed as the pen moves, but if any bitmap in the stack *might* have completely changed (programmers are lazy they call Refresh too often), then the whole stack ends up being composited onto the screen. A screen can be 16MB, and 50 layers would be 800 Mb, so, worst case, nearly 1GB of data is composited on the screen, 50 times a second.
50GB a second? Too much data, it cannot keep up.
You see why graphics cards have such high bandwidths and why Android refreshes can be slow?
How would I fix that?
Well redraw is on one thread, so I cannot multi-thread that one-and-only redraw, but the pen can be tracked by a separate thread so I can track it very accurately very quickly. The screen will lag but the pen will track properly. That won't look good in videos, but it is a sort of fix. Not one marketing will like.
I can also fix the redraw and aggressively force the tiniest rectangle to redraw, and the wider rectangle that I am less certain needs updating? Well I can refresh that at a slower rate. That would be better, but complicated and would have temporary artifacts, and does not appear to have been done.
No, instead, they seem to have estimated where the next point will be, done the full redraw. If the full redraw takes 100ms, and I can estimate roughly where the pen will be in the range 91ms to 109 ms, then I can claim a refresh rate of 9ms. I am estimating where it will be when my redraw finishes, and as long as I'm approximately correct it will appear to be responsive.
Only sometimes my estimate will be spectacularly wrong.
So many things in the Samsung unpacked annoyed me. It seems they are guessing as to what users might want, and disinterested focus groups are telling them where they should head and their hacks are nasty.
Please tell me that connecting the keyboard to a tablet doesn't switch the tablet into Dex mode?, as if you want everything to change when you put it into its keyboard!!!??? I was literally using the tablet and now suddenly, connect a keyboard the fucking thing totally changes into a poor Windows copy? WHY?
/ late / rant