Default dwmFlush=0 (plain vsync pacing)

src/config.cpp

@@ -72,8 +72,8 @@ Config LoadConfig(const std::wstring& path) {
                "tickHzCap=0\n"
                "; vsync: 1=present locked to display refresh (smooth, capped); 0=no vsync, paced by tickHzCap (restart to apply)\n"
                "vsync=1\n"
-               "; dwmFlush: 1=pace the zoomed loop to DWM's composition (smooth, default); 0=old vsync pacing\n"
-               "dwmFlush=1\n"
+               "; dwmFlush: 0=plain vsync pacing (default, fewer stutters); 1=align to DWM's composition\n"
+               "dwmFlush=0\n"
                "; diagnostics=1 logs frame timing to %TEMP%\\wind_diag.log (restart to apply)\n"
                "diagnostics=0\n"
                "; cursorSensitivity: pan speed per raw count\n"

src/config.h

@@ -16,11 +16,11 @@ struct Config {
     // Present sync while zoomed (render engine): 1 = vsync (Present sync-interval 1, locked to
     // the display refresh); 0 = no vsync (Present 0), with the loop paced by tickHzCap instead.
     int    vsync            = 1;
-    // Pace the zoomed loop with DwmFlush() instead of vsync/timer: present immediately (no vsync
-    // block) then block until DWM's next composition, so our frames align 1:1 with the
-    // compositor. Fixes the blt-model microstutter (phase mismatch between our Present and DWM's
-    // composite) - default ON. 1 = on (overrides vsync while zoomed), 0 = old vsync pacing.
-    int    dwmFlush         = 1;
+    // Zoomed-loop pacing. 0 (default) = plain vsync Present(1,0); measured fewer stutters in
+    // general (desktop + games), and it doesn't slip toward half-rate under a heavy fullscreen
+    // game the way DwmFlush can. 1 = present immediately then DwmFlush() to align 1:1 with DWM's
+    // composition (overrides vsync while zoomed). Hot-reloadable.
+    int    dwmFlush         = 0;
     int    diagnostics      = 0;     // 1 = log frame-timing to wind_diag.log
 
     // --- Own GPU renderer ---------------------------------------------------

tests/test_config.cpp

@@ -30,7 +30,7 @@ TEST_CASE("renderer knobs have sane defaults") {
     CHECK(c.hdrTonemap == 1);                  // on by default (no-op on SDR)
     CHECK(c.cursorVisibility == "auto");       // follow the focused app by default
     CHECK(c.vsync == 1);                       // vsync on by default
-    CHECK(c.dwmFlush == 1);                     // DwmFlush pacing on by default (the smooth path)
+    CHECK(c.dwmFlush == 0);                     // plain vsync pacing by default (fewer stutters)
     CHECK(c.tickHzCap == 0);                    // 0 = auto-detect display refresh rate
 }
 TEST_CASE("vsync, dwmFlush, tickHzCap can be set") {

tools/uiaccess_setup.ps1

@@ -77,9 +77,9 @@ brightness=1.0
 hdrTonemap=1
 tickHzCap=0
 vsync=1
-; dwmFlush: 1=pace the zoomed loop to DWM's composition (microstutter test). Hot-reloadable -
-;   edit this to 0 and save to compare (run notepad as admin, or via the tray "Edit config").
-dwmFlush=1
+; dwmFlush: 0=plain vsync pacing (default, fewer stutters); 1=align to DWM's composition.
+;   Hot-reloadable - edit and save to compare (notepad as admin, or the tray "Edit config").
+dwmFlush=0
 "@
     Set-Content -Path "C:\Program Files\Wind\magnifier.ini" -Value $ini -Encoding ASCII