diff --git a/iac/provider-gcp/main.tf b/iac/provider-gcp/main.tf
index 747fa95db3..36641e08f3 100644
--- a/iac/provider-gcp/main.tf
+++ b/iac/provider-gcp/main.tf
@@ -81,8 +81,13 @@ locals {
     "local_lock=none", // all locks are network locks
 
     // caching
-    "noac",             // disable attribute caching. slower, but more reliable
-    "lookupcache=none", // disable lookup caching
+    // Bound cross-host staleness to ~1s while avoiding a Filestore RPC on every
+    // metadata op. Sandboxes mounting the same volume on different hosts still see
+    // peer writes within the attribute timer; strict coherency for shared mutable
+    // state should use NLM locks (already enabled via lock,local_lock=none) or an
+    // out-of-band signal.
+    "actimeo=1",            // cap all attribute caches at 1 second
+    "lookupcache=positive", // cache hits; negative lookups still hit the server so new files appear promptly
 
     // security
     "noacl",   // do not use an acl
diff --git a/iac/provider-gcp/nomad-cluster/scripts/start-client.sh b/iac/provider-gcp/nomad-cluster/scripts/start-client.sh
index e4d6f68d10..a1a5712051 100755
--- a/iac/provider-gcp/nomad-cluster/scripts/start-client.sh
+++ b/iac/provider-gcp/nomad-cluster/scripts/start-client.sh
@@ -83,6 +83,19 @@ echo "$SWAPFILE none swap sw 0 0" | tee -a /etc/fstab
 sysctl vm.swappiness=10
 sysctl vm.vfs_cache_pressure=50
 
+# Increase RPC slot table so nconnect can actually parallelize. Default of 2 in-flight
+# RPCs per TCP connection bottlenecks metadata-heavy NFS workloads (uncached lookups,
+# many concurrent sandboxes). Modprobe options apply when sunrpc loads (first NFS mount);
+# the runtime sysctl handles the case where the module is already loaded.
+mkdir -p /etc/modprobe.d
+cat <<'EOF' >/etc/modprobe.d/sunrpc.conf
+options sunrpc tcp_slot_table_entries=128 tcp_max_slot_table_entries=128
+EOF
+if [ -d /proc/sys/sunrpc ]; then
+  sysctl -w sunrpc.tcp_slot_table_entries=128
+  sysctl -w sunrpc.tcp_max_slot_table_entries=128
+fi
+
 # TODO: Optimize the mount more according to https://cloud.google.com/filestore/docs/mounting-fileshares
 %{ if USE_FILESTORE_CACHE }
 # Configure NFS read ahead