diff --git a/spack.yaml b/spack.yaml
index ab00b83..d032a02 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -13,50 +13,55 @@ spack:
       require:
         - '@2025.08.000'
         - configurations=MOM6,MOM6-CICE6,MOM6-CICE6-WW3
-        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
+        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'ldflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto -fuse-ld=lld"'
     access-cice:
       require:
         - '@CICE6.6.1-0'
         - io_type=PIO
-        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
+        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3"'
+        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3"'
     access-mom6:
       require:
-        - '@2025.07.000'
-        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
+        - '@git.9b5014887a95cfbe9462079d8f938a4d5d73ab11=2026.01.000'  # On branch dev/gfdl+access+isf
+        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'ldflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto -fuse-ld=lld"'
     access-ww3:
       require:
         - '@2025.08.000'
     access3-share:
       require:
         - '@2025.08.000'
-        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
+        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'ldflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto -fuse-ld=lld"'
     access-generic-tracers:
       require:
         - '@2025.08.000'
-        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
+        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'ldflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto -fuse-ld=lld"'
     access-mocsy:
       require:
         - '@2025.07.002'
-        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
+        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'ldflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto -fuse-ld=lld"'
+    fms:
+      require:
+        - '@2025.03'
+        - 'cppflags="-DMAXFIELDMETHODS_=600"'
+        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto"'
+        - 'ldflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3 -flto -fuse-ld=lld"'
     # Other Dependencies
     esmf:
       require:
         - '@8.7.0'
-        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
-        - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll"'
+        - 'fflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3"'
+        - 'cflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3"'
+        - 'cxxflags="-march=sapphirerapids -mtune=sapphirerapids -unroll -O3"'
     parallelio:
       require:
         - '@2.6.2'
@@ -67,10 +72,6 @@ spack:
     netcdf-fortran:
       require:
         - '@4.6.1'
-    fms:
-      require:
-        - '@2025.03'
-        - 'cppflags="-DMAXFIELDMETHODS_=600"'
     openmpi:
       require:
         - '@4.1.7'
@@ -84,6 +85,8 @@ spack:
       require:
         - '%oneapi@2025.2.0'
         - 'target=x86_64_v4'
+  config:
+    build_jobs: 1
   view: true
   concretizer:
     unify: true