diff --git a/projects/ArchR/packages/emulators/standalone/flycast-sa/package.mk b/projects/ArchR/packages/emulators/standalone/flycast-sa/package.mk
index 0aa80d7aeb..6d45f8d0b6 100644
--- a/projects/ArchR/packages/emulators/standalone/flycast-sa/package.mk
+++ b/projects/ArchR/packages/emulators/standalone/flycast-sa/package.mk
@@ -32,7 +32,11 @@ fi
 
 pre_configure_target() {
   export CXXFLAGS="${CXXFLAGS} -Wno-error=array-bounds"
-  PKG_CMAKE_OPTS_TARGET+=" -DCMAKE_BUILD_TYPE=Release -DUSE_OPENMP=ON"
+  PKG_CMAKE_OPTS_TARGET+=" -DUSE_OPENMP=ON"
+  # -Ofast is intentional for Flycast: SH4 FPU emulation doesn't require
+  # strict IEEE 754, and Dreamcast hardware itself flushes denormals.
+  # Validated by JELOS/AmberELEC/ROCKNIX upstream for years.
+  sed -i 's/\-O[23]/-Ofast/' ${PKG_BUILD}/CMakeLists.txt
 }
 
 makeinstall_target() {
diff --git a/projects/ArchR/packages/sysutils/systemd/config/sysctl.d/archr.conf b/projects/ArchR/packages/sysutils/systemd/config/sysctl.d/archr.conf
index a46080c7df..2169da5069 100644
--- a/projects/ArchR/packages/sysutils/systemd/config/sysctl.d/archr.conf
+++ b/projects/ArchR/packages/sysutils/systemd/config/sysctl.d/archr.conf
@@ -1,9 +1,9 @@
 kernel.nmi_watchdog=0
 vm.swappiness=1
 vm.laptop_mode=0
-vm.dirty_writeback_centisecs=500
+vm.dirty_writeback_centisecs=1500
 vm.dirty_expire_centisecs=3000
-vm.vfs_cache_pressure=50
+vm.vfs_cache_pressure=100
 vm.dirty_ratio=10
 vm.dirty_background_ratio=5
 vm.page-cluster=0