feat: VRAM booster only for GPUs with at least 2 GB of their own VRAM

AGENTS.md

@@ -234,7 +234,7 @@ gamescope and the Plasma desktop. Primary target: the Valve Steam Machine
   new major kernel.
 - VRAM booster (`vram`, `lib/vram-booster.sh`, top-level, ticked by
   default, 2.3.0; only available when `/sys/fs/cgroup/dmem.capacity` lists a
-  region): CachyOS's `dmemcg-booster` (system + user service) and
+  VRAM region of at least 2 GB): CachyOS's `dmemcg-booster` (system + user service) and
   `plasma-foreground-booster`, like SteamOS 3.9's VRAM management. The
   latter only starts with `kcgroupsrc [Foreground Booster] autostart=true`
   (set with `kset`). Disable removes only the packages it installed

CHANGELOG.md

@@ -7,7 +7,8 @@ one per merged pull request.
 
 ## 2.3.0 - 2026-09-27
 
-- **feat: VRAM booster for every supported GPU, not only the Steam Machine**
+- **feat: VRAM booster only for GPUs with at least 2 GB of their own VRAM**
+- `3f97c85` **feat: VRAM booster for every supported GPU, not only the Steam Machine**
 - `fd162c1` **feat: New badge for default sub-options added in this version**
 - `54ebddf` **feat: VRAM booster for the Steam Machine**
 

TECHNICAL.md

@@ -244,7 +244,8 @@ most of the VRAM (8 GB on the Steam Machine) can be pushed into system RAM
 by the desktop and other apps, and stutter. The kernel side is the `dmem`
 cgroup controller (7.2); amdgpu and Intel's xe register their VRAM with it,
 NVIDIA's driver doesn't. The **VRAM booster** option is only shown when
-`/sys/fs/cgroup/dmem.capacity` lists a region (or it's already on), and is
+`/sys/fs/cgroup/dmem.capacity` lists a VRAM region of at least 2 GB (a
+dedicated GPU; an integrated one registers a small carve-out) or it's already on, and is
 ticked by default; new in 2.3.0, so setups with the SteamOS conversion on
 get it ticked. CachyOS packages the userspace side, which it installs:
 

lib/vram-booster.sh

@@ -4,7 +4,7 @@
 # are evicted first, so a game that needs most of it doesn't spill into
 # system RAM and stutter. The kernel side is the dmem cgroup controller
 # (7.2; amdgpu and xe register their VRAM, NVIDIA's driver doesn't), so it's
-# only offered when the kernel lists a region. CachyOS packages the userspace
+# only offered when the kernel lists a VRAM region of at least 2 GB. CachyOS packages the userspace
 # side: dmemcg-booster (a system service that enables the controller and
 # sets the limits, plus a user service) and plasma-foreground-booster, which
 # tells it which window is in front on the desktop. The latter only starts
@@ -12,10 +12,13 @@
 # Sourced by steamify.sh; not meant to be run on its own.
 
 VRAM_PKGS=(dmemcg-booster plasma-foreground-booster)
+VRAM_MIN_BYTES=$((2 * 1024 * 1024 * 1024))
 
 vram_available() {
-    # cgroupfs files have size 0, so read it.
-    grep -q . /sys/fs/cgroup/dmem.capacity 2>/dev/null || vram_status
+    # Only for a GPU with its own VRAM: an integrated GPU registers a small
+    # carve-out too, but mostly uses system RAM, so there's little to boost.
+    awk -v min="$VRAM_MIN_BYTES" '$1 ~ /\/vram$/ && $2 >= min { found = 1 } END { exit !found }' \
+        /sys/fs/cgroup/dmem.capacity 2>/dev/null || vram_status
 }
 
 vram_status() {