diff --git a/hw/straylight/default.nix b/hw/straylight/default.nix
index d630186..90b351b 100644
--- a/hw/straylight/default.nix
+++ b/hw/straylight/default.nix
@@ -25,6 +25,11 @@ in
   ];
 
   config = {
+    # Let the GPU address up to 104 GiB of the 128 GiB of unified memory (the TTM default
+    # caps GTT at 50% of RAM, ~62 GiB). Units are 4 KiB pages; takes effect after a reboot.
+    # amdgpu.gttsize is deprecated on recent kernels; ttm.* is the supported knob.
+    boot.kernelParams = [ "ttm.pages_limit=27262976" "ttm.page_pool_size=27262976" ];
+
     # llama.cpp server with Vulkan backend for gfx1151 (Strix Halo).
     # Model is downloaded from HuggingFace on first start and cached in StateDirectory.
     # NOTE: BIOS "UMA Frame Buffer Size" must be ≥32GB for a 23GB model to fit on-GPU.