diff --git a/host-specific/shizuri/boot.nix b/host-specific/shizuri/boot.nix
index 1ef8f3f..aad94fb 100644
--- a/host-specific/shizuri/boot.nix
+++ b/host-specific/shizuri/boot.nix
@@ -8,5 +8,13 @@
   # cwsr enabled on this kernel, breaking every HIP launch with
   # HSA_STATUS_ERROR_OUT_OF_RESOURCES.  Disabling compute wave save/restore
   # works around it until the kernel-side path stabilizes.
-  boot.kernelParams = [ "amdgpu.cwsr_enable=0" ];
+  # The firmware UMA carveout is set to its 512 MiB minimum, leaving system
+  # memory available through GTT for resident models and ROCm graph state.
+  boot.kernelParams = [
+    "amdgpu.cwsr_enable=0"
+    "amd_iommu=off"
+    "amdgpu.gttsize=126976"
+    "ttm.pages_limit=32505856"
+    "ttm.page_pool_size=32505856"
+  ];
 }