What's new in v0.9.0-beta.3

Three changes, all about the display: a new refresh rate for PAL games, and two
fixes to the Display & Sound page itself.

100 Hz, and 90 Hz is gone

The refresh rate choices are now 60, 100, and 120 Hz.

A rate is only worth having if it divides evenly into a frame rate. 60 and 120
suit 60fps NTSC games. 100 is for 50fps PAL games, and it is the only rate
that divides into 50 cleanly: at 60 Hz a PAL game has to hold some frames on
screen longer than others, and that unevenness is the stutter you see in
scrolling.

90 Hz has been removed. It divided into nothing anyone plays. At 1.5 times
60fps it forced an uneven hold that juddered 60fps games worse than plain 60 Hz
did. If your handheld is currently set to 90, it will move to the nearest rate
that is still offered.

Black Frame Insertion now works at 100 Hz

Black Frame Insertion needs the panel running at exactly twice the game's frame
rate, so every frame gets one lit refresh and one black one. Until now it was
locked to 120 Hz, which meant it only ever served 60fps games.

It now works at 100 Hz for 50fps PAL games as well. That restriction was ours,
not RetroArch's.

The row tells you which frame rate it is currently set up for, such as "On (50
fps)". Match that to what you are playing. A 60fps game left running at 100 Hz
will be paced down to 50 and run slow.

This was measured on hardware before it was built, because the feature would be a
lie if the panel could not keep up: black frames count as frames, so 100 Hz asks
for 100 of them every second. It holds.

The Display & Sound page is no longer sluggish

Moving the cursor on Settings > Display & Sound dragged, and only on that
page. It was making four separate requests to the background service, one after
another, on the same thread that draws the screen, every 300 milliseconds the page
was open. Each request took about 78 milliseconds, and nothing could be drawn
while it waited.

This is a long-standing bug, not a new one. It has been in every release since
roughly early June. It was never chased down because the page still worked, it
just felt bad.

The Test Sound row is no longer cut off

At Extra Large font with the button hints showing, the last row on Display &
Sound rendered underneath the hint bar, with both its label and value clipped. The
page now fits its rows to the space it actually has.

Testing notes

The obvious pass is Settings > Display & Sound at every font size, with and
without button hints, checking that no row is clipped or hidden behind the hints.
Cursor movement on that page should now feel the same as anywhere else.

For the display changes:

• PAL games at 100 Hz. Anything European: side-scrollers make stutter easiest
  to see. Compare 100 against 60 on the same game.
• PAL games at 100 Hz with Black Frame Insertion on. This pairing is brand
  new. Check it holds full speed, and that motion looks sharper rather than
  dimmer-and-the-same.
• If you were running 90 Hz, check where your handheld landed and that the
  setting reads correctly after a reboot.
• Shaders at 100 Hz with BFI on are untested. If a PAL game with a shader runs
  short of full speed, turn BFI off first and say so in a report.
• Worth confirming a 60fps game at 100 Hz does run slow, and that the row's
  "On (50 fps)" label made that predictable rather than mysterious.

Everything from beta.1 and beta.2 still applies. Recording is still off by default
under Settings > Controls & Feedback, and the question from beta.2 is still
open: does a game run any differently with the recording dot on screen?