From ec1e2efbbaeb9ff239abf01aa1081b4122100d28 Mon Sep 17 00:00:00 2001 From: "K. Isom" Date: Tue, 15 Sep 2026 19:54:51 -0700 Subject: [PATCH] straylight: raise the GPU memory ceiling to 104 GiB The TTM default caps GTT at half of RAM (~62 GiB), which is too small for the 118B-parameter model straylight will serve. Set ttm.pages_limit and ttm.page_pool_size to 27262976 pages (104 GiB); takes effect on reboot. Co-Authored-By: Claude Fable 5.1 --- hw/straylight/default.nix | 5 +++++ 1 file changed, 5 insertions(+) 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.