diff --git a/hosts/common/configs/system/nixpkgs/default.nix b/hosts/common/configs/system/nixpkgs/default.nix
index 14d9d03..60acaf1 100644
--- a/hosts/common/configs/system/nixpkgs/default.nix
+++ b/hosts/common/configs/system/nixpkgs/default.nix
@@ -1,6 +1,9 @@
-{ inputs, ... }:
+{ inputs, system, ... }:
 {
   imports = [ inputs.nur.modules.nixos.default ];
 
-  nixpkgs.config.allowUnfree = true;
+  nixpkgs = {
+    hostPlatform = system;
+    config.allowUnfree = true;
+  };
 }
diff --git a/hosts/common/configs/system/powertop/default.nix b/hosts/common/configs/system/powertop/default.nix
index 774061d..199bb2f 100644
--- a/hosts/common/configs/system/powertop/default.nix
+++ b/hosts/common/configs/system/powertop/default.nix
@@ -2,4 +2,5 @@
 {
   environment.systemPackages = with pkgs; [ powertop ];
   powerManagement.powertop.enable = true;
+  systemd.services.powertop.postStart = builtins.readFile ./mouse.sh;
 }
diff --git a/hosts/eirene/hardware/scripts/mouse.sh b/hosts/common/configs/system/powertop/mouse.sh
similarity index 93%
rename from hosts/eirene/hardware/scripts/mouse.sh
rename to hosts/common/configs/system/powertop/mouse.sh
index a234006..dc0f6ea 100644
--- a/hosts/eirene/hardware/scripts/mouse.sh
+++ b/hosts/common/configs/system/powertop/mouse.sh
@@ -1,6 +1,5 @@
 SEARCH_STRINGS=(
   "Mouse"
-  "Razer DeathAdder Elite"
   "Razer DeathAdder V3 HyperSpeed"
 )
 
diff --git a/hosts/common/configs/user/gui/obs/options.nix b/hosts/common/configs/user/gui/obs/options.nix
index 723692c..3339a12 100644
--- a/hosts/common/configs/user/gui/obs/options.nix
+++ b/hosts/common/configs/user/gui/obs/options.nix
@@ -8,11 +8,13 @@
         x = mkOption {
           type = int;
           description = "Base resolution width.";
+          default = 1920;
         };
 
         y = mkOption {
           type = int;
           description = "Base resolution height.";
+          default = 1080;
         };
       };
 
@@ -20,11 +22,13 @@
         x = mkOption {
           type = int;
           description = "Output resolution width.";
+          default = 1920;
         };
 
         y = mkOption {
           type = int;
           description = "Output resolution height.";
+          default = 1080;
         };
       };
     };
diff --git a/hosts/eirene/hardware/scripts/card.sh b/hosts/eirene/hardware/card.sh
similarity index 100%
rename from hosts/eirene/hardware/scripts/card.sh
rename to hosts/eirene/hardware/card.sh
diff --git a/hosts/eirene/hardware/default.nix b/hosts/eirene/hardware/default.nix
index 889b43b..0abe4b3 100644
--- a/hosts/eirene/hardware/default.nix
+++ b/hosts/eirene/hardware/default.nix
@@ -62,23 +62,17 @@
     ];
   };
 
-  nixpkgs = {
-    hostPlatform = "x86_64-linux";
-
-    config = {
-      cudaSupport = true;
-      rocmSupport = true;
-    };
+  nixpkgs.config = {
+    cudaSupport = true;
+    rocmSupport = true;
   };
 
   powerManagement.enable = true;
 
-  systemd.services.powertop.postStart = builtins.readFile ./scripts/mouse.sh;
-
   services = {
     xserver.videoDrivers = [ "nvidia" ];
     fstrim.enable = true;
-    tlp.settings.DISK_DEVICES = "nvme0n1 nvme1n1";
+    tlp.settings.DISK_DEVICES = lib.mkDefault "nvme0n1 nvme1n1";
   };
 
   programs.gamescope.env = {
@@ -100,7 +94,7 @@
         gestures.workspace_swipe_distance = 600;
       };
 
-      programs.zsh.loginExtra = lib.mkBefore (builtins.readFile ./scripts/card.sh);
+      programs.zsh.loginExtra = lib.mkBefore (builtins.readFile ./card.sh);
     }
   ];
 }
diff --git a/hosts/elara/default.nix b/hosts/elara/default.nix
index 1a0cb4d..da0b5a5 100644
--- a/hosts/elara/default.nix
+++ b/hosts/elara/default.nix
@@ -8,8 +8,6 @@
       device = "/dev/disk/by-id/ata-Samsung_SSD_990_EVO_1TB_S7GCNL0XA04998F";
     })
     ./hardware
-    # elara runs on an external drive on eirene
-    ../eirene/hardware
 
     ../common/configs/system/backup
     ../common/configs/system/bluetooth
diff --git a/hosts/elara/hardware/default.nix b/hosts/elara/hardware/default.nix
index 7b6fafe..c6f8bfb 100644
--- a/hosts/elara/hardware/default.nix
+++ b/hosts/elara/hardware/default.nix
@@ -5,4 +5,15 @@
     "uas"
     "sd_mod"
   ];
+
+  services.tlp.settings.DISK_DEVICES = "sda";
+
+  # By default, this host runs on an external SSD attached to eirene...
+  imports = [ ../../eirene/hardware ];
+
+  # ...but it can also run attached to a SAS-provided laptop.
+  specialisation.sas.configuration = {
+    disabledModules = [ ../../eirene/hardware ];
+    imports = [ ./sas ];
+  };
 }
diff --git a/hosts/elara/hardware/sas/default.nix b/hosts/elara/hardware/sas/default.nix
new file mode 100644
index 0000000..3c75e5d
--- /dev/null
+++ b/hosts/elara/hardware/sas/default.nix
@@ -0,0 +1,29 @@
+{ ... }:
+{
+  imports = [
+    ./display.nix
+  ];
+
+  hardware = {
+    enableAllFirmware = true;
+
+    cpu = {
+      cores = 8;
+      threads = 12;
+      intel.updateMicrocode = true;
+    };
+  };
+
+  boot = {
+    kernelModules = [ "kvm-intel" ];
+    initrd.kernelModules = [
+      "thunderbolt"
+      "vmd"
+      "nvme"
+    ];
+  };
+
+  powerManagement.enable = true;
+
+  services.fstrim.enable = true;
+}
diff --git a/hosts/elara/hardware/sas/display.nix b/hosts/elara/hardware/sas/display.nix
new file mode 100644
index 0000000..4735b65
--- /dev/null
+++ b/hosts/elara/hardware/sas/display.nix
@@ -0,0 +1,28 @@
+{ ... }:
+{
+  boot.kernelParams = [ "video=eDP-1:1920x1200@60" ];
+
+  home-manager.sharedModules = [
+    {
+      wayland.windowManager.hyprland.settings.monitor = "eDP-1, 1920x1200@60, 0x0, 1";
+
+      programs = {
+        vscode.userSettings."window.zoomLevel" = (1.25 - 1) / 0.2;
+
+        obs-studio.resolution = {
+          base = {
+            x = 1920;
+            y = 1200;
+          };
+
+          output = {
+            x = 1920;
+            y = 1200;
+          };
+        };
+      };
+
+      theme.cursor.size = 24;
+    }
+  ];
+}
diff --git a/hosts/installer/hardware/default.nix b/hosts/installer/hardware/default.nix
index f49890e..65338c8 100644
--- a/hosts/installer/hardware/default.nix
+++ b/hosts/installer/hardware/default.nix
@@ -1,6 +1,6 @@
 { ... }:
 {
-  hardware.enableAllFirmware = true;
+  hardware.enableAllHardware = true;
 
   boot.initrd.kernelModules = [
     "nvme"
@@ -11,7 +11,5 @@
     "sd_mod"
   ];
 
-  nixpkgs.hostPlatform = "x86_64-linux";
-
   services.fstrim.enable = true;
 }