diff --git a/README.md b/README.md
index 937f511..00f92a0 100644
--- a/README.md
+++ b/README.md
@@ -41,20 +41,20 @@ server address already filled in.
 
 ## Memory
 
-The heap defaults to 13 GB (`-X`/`-x` to change it). `-XX:+AlwaysPreTouch` means
-the JVM commits the whole heap at startup rather than growing into it.
+The heap defaults to 10 GB (`-X`/`-x` to change it). `-XX:+AlwaysPreTouch` means
+the JVM commits the whole heap at startup rather than growing into it, so the
+number you set is the number actually taken.
 
-On a ZFS host, cap the ARC before running a heap this large — ZFS defaults to
-using up to half of RAM for cache, which will fight the JVM for the same pages:
+On a ZFS host, cap the ARC to go with it — ZFS defaults to using up to half of
+RAM for cache, and will otherwise contend with the JVM for the same pages:
 
 ```bash
 echo "options zfs zfs_arc_max=2147483648" | sudo tee /etc/modprobe.d/zfs.conf
 sudo dracut --force && sudo reboot
 ```
 
-That pins the ARC to 2 GB. On a 16 GB box, 13 GB heap + 2 GB ARC leaves ~1 GB
-for everything else, which is tight — drop the heap to 10–11 GB if the host
-does anything besides run the server.
+That pins the ARC to 2 GB. On a 16 GB box that leaves roughly 4 GB for the OS
+and anything else the host runs, which is comfortable.
 
 ## Requirements
 
diff --git a/deploy.sh b/deploy.sh
index 9a38d8f..a2167e4 100755
--- a/deploy.sh
+++ b/deploy.sh
@@ -14,7 +14,7 @@
 set -euo pipefail
 
 NAME=""; AUTHOR=""; BASEURL=""; NFVER="latest"; MCVER="1.21.1"
-SHARE="/minecraft"; XMX="13G"; XMS="13G"; ACCEPT_EULA=""
+SHARE="/minecraft"; XMX="10G"; XMS="10G"; ACCEPT_EULA=""
 HERE="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
 
 die()  { echo "error: $*" >&2; exit 1; }
diff --git a/mc-service-setup.sh b/mc-service-setup.sh
index a711286..d7e8cc2 100755
--- a/mc-service-setup.sh
+++ b/mc-service-setup.sh
@@ -18,8 +18,8 @@ set -euo pipefail
 
 SHARE="/minecraft"
 MCUSER="minecraft"
-XMS="13G"
-XMX="13G"
+XMS="10G"
+XMX="10G"
 NFVER=""                  # version, or "latest" to resolve one; empty = don't install
 MCVER="1.21.1"            # only used to pick the matching NeoForge series
 ADMIN=""                  # human user who authors the pack on the share