diff --git a/scripts/library_run.py b/scripts/library_run.py
index d5d435f..c13644a 100644
--- a/scripts/library_run.py
+++ b/scripts/library_run.py
@@ -111,8 +111,11 @@ DECODE_CHECK = True
 CQ_NVENC = 31            # measured: min SSIM 0.989-0.994 at 43-74% of the source video bitrate
 CRF_X265 = 26            # measured: min SSIM 0.988-0.993 at 34-67% -- 10-22% smaller than NVENC
                          # at matched SSIM. crf24 = the conservative option (min 0.990-0.994, 43-84%)
-NVENC_PRESET = "p6"
-X265_PRESET = "medium"
+NVENC_PRESET = "p7"        # owner default (2026-10-12): the GPU ASIC has spare time, and each step
+# up this ladder buys size at the same CQ. Overridable per run with --nvenc-preset; the control
+# plane passes its own setting, so this constant is only the fallback for a hand-run engine.
+X265_PRESET = "medium"     # ... and the CPU is the contended resource here (three workers run side
+# by side), so the x265 default stays `medium`; --x265-preset / the dashboard can move it.
 X265_POOLS = 10          # E-cores only (affinity 0x3FF0000)
 E_CORE_MASK = 0x3FF0000
 SSIM_TARGET = 0.985      # per-frame floor vs the source window (480x270 comparison)