diff --git a/nx2navi.ini.example b/nx2navi.ini.example
index 2ee99ddc..cbb85b6e 100644
--- a/nx2navi.ini.example
+++ b/nx2navi.ini.example
@@ -150,6 +150,9 @@
 # skip push constants that did not change.
 # bind_skip = 1
 # shader_memo = 1
+# 1 flushes every shader cache file to the disk before it is used, as earlier versions did; 0 (default) flushes only
+# the stored game code, which makes shader preparation about twice as fast (a torn file is translated again).
+# shader_cache_flush = 0
 # pipe_memo = 1
 # tex_memo = 1
 # desc_template = 1
diff --git a/runtime/cfg.c b/runtime/cfg.c
index 61aeb9b3..6aee9bb4 100644
--- a/runtime/cfg.c
+++ b/runtime/cfg.c
@@ -56,7 +56,7 @@ static const char *const known[] = {
     "REFLEX", "RENDER_SCALE", "REPLAY_ASYNC", "RTSS",
     "REPLAY_CHECK", "RESOLVE_CHECK", "RESTART_WAIT", "ROMFS", "ROMFS_INDEX", "ROMFS_MMAP", "ROMFS_MODS", "ROMFS_PATCHES",
     "ROMFS_PROOF_DIR", "ROMFS_VERIFY", "RSTICK_DEADZONE", "RUMBLE", "RUMBLE_CURVE", "RUMBLE_STRENGTH", "RUMBLE_TRIGGERS", "SHADER_CACHE",
-    "SHADER_MEMO", "SHADOW_COMPARE", "SHADOW_RANGE", "SHADOW_RES", "SHADOW_SCALE", "SHARED_FONTS", "SHARPNESS", "SHOTS", "SHOTS_DIR",
+    "SHADER_CACHE_FLUSH", "SHADER_MEMO", "SHADOW_COMPARE", "SHADOW_RANGE", "SHADOW_RES", "SHADOW_SCALE", "SHARED_FONTS", "SHARPNESS", "SHOTS", "SHOTS_DIR",
     "SVC_SLOW_MS",
     "SHOTS_FULL", "SPEED_PROBE", "SPIN", "SPIN_HANDOFF_US", "SPLIT_DRAWS", "SPLIT_US", "SPV_OVERRIDE", "STICK_DEADZONE", "STICK_SENS",
     "SWKBD_ANSWER",
@@ -110,7 +110,7 @@ static const struct { const char *key, *section; } sections[] = {
     {"LIB_PREBUILD", "performance"}, {"LIB_PREBUILD_THREADS", "performance"}, {"PIPE_PREBUILD", "performance"},
     {"PREWARM_XLATE", "performance"}, {"GPL", "performance"}, {"ASTC", "performance"}, {"MEMORY", "performance"},
     {"TEX_ALIAS", "performance"}, {"TEX_VRAM_PRESSURE", "performance"}, {"ASTC_BC", "performance"}, {"LOD_GUARD", "performance"}, {"FIX_C0", "performance"}, {"FIX_ZERO", "performance"},
-    {"BIND_SKIP", "performance"}, {"SHADER_MEMO", "performance"}, {"PIPE_MEMO", "performance"}, {"TEX_MEMO", "performance"}, {"DESC_TEMPLATE", "performance"},
+    {"BIND_SKIP", "performance"}, {"SHADER_CACHE_FLUSH", "performance"}, {"SHADER_MEMO", "performance"}, {"PIPE_MEMO", "performance"}, {"TEX_MEMO", "performance"}, {"DESC_TEMPLATE", "performance"},
     {"PUSH_SKIP", "performance"}, {"SPLIT_DRAWS", "performance"}, {"SPLIT_US", "performance"}, {"VK_VALIDATION", "performance"},
     {"VK_DYN_VERTEX", "performance"}, {"VK_DYN_A2C", "performance"}, {"VK_SUBGROUP_PIN", "performance"}, {"VK_RECONVERGE", "performance"},
     {"TRACE", "diagnostics"}, {"FLIGHT", "diagnostics"}, {"PASS_CRUMBS", "diagnostics"}, {"FLIGHT_SPIKE_MS", "diagnostics"},
@@ -209,7 +209,7 @@ static const CfgMeta metas[] = {
     {"ASTC_SCRATCH_KEEP", "0", "0|1", RESTART}, {"ASTC_ARENA", "0", "0|1", RESTART},   // vk_astc.c scratch_get, vk_texture.c astc_arena
     // render fixes
     {"LOD_GUARD", "1", "0|1", RESTART}, {"FIX_C0", "1", "0|1", RESTART}, {"FIX_ZERO", "1", "0|1", RESTART},
-    {"BIND_SKIP", "1", "0|1", RESTART}, {"SHADER_MEMO", "1", "0|1", RESTART}, {"PIPE_MEMO", "1", "0|1", RESTART}, {"TEX_MEMO", "1", "0|1", RESTART},
+    {"BIND_SKIP", "1", "0|1", RESTART}, {"SHADER_CACHE_FLUSH", "0", "0|1", RESTART}, {"SHADER_MEMO", "1", "0|1", RESTART}, {"PIPE_MEMO", "1", "0|1", RESTART}, {"TEX_MEMO", "1", "0|1", RESTART},
     {"BIND_REUSE", "1", "0|1", RESTART}, {"DYN_DELTA", "1", "0|1", RESTART},
     {"DESC_TEMPLATE", "1", "0|1", RESTART},
     {"PUSH_SKIP", "1", "0|1", RESTART}, {"SPLIT_DRAWS", "64", "0..1000", RESTART},
diff --git a/runtime/gfx_shader.c b/runtime/gfx_shader.c
index ecd1e4ce..d54fe8a1 100644
--- a/runtime/gfx_shader.c
+++ b/runtime/gfx_shader.c
@@ -1063,11 +1063,20 @@ static int use_find(const uint8_t h[32], UseMask *m) {
     return known;
 }
 
+// NX2NAVI_SHADER_CACHE_FLUSH (default 0): 1 flushes the .spv, .res.json and .use files to the disk too, as the cache
+// did before (see "Durability" at the top), for a drive or setup where a torn file was seen.
+static int cache_flush(void) {
+    static int on = -1;
+    if (on < 0) on = rt_knob("SHADER_CACHE_FLUSH", "0") == 1;
+    return on;
+}
+
 static void use_store(const uint8_t h[32], const UseMask *m) {
     char p[PATH_CAP + 80];
     use_path(h, p);
     uint32_t f[5] = {USE_MAGIC, USE_VERSION, m->slots, m->attrs, m->fouts};
-    plat_file_write_cached(p, f, sizeof f);   // not flushed: a torn mask fails its magic and size check (see the top)
+    if (cache_flush()) plat_file_write_atomic(p, f, sizeof f);
+    else plat_file_write_cached(p, f, sizeof f);   // not flushed: a torn mask fails its magic and size check (see the top)
     plat_mutex_lock(&cache_lock);
     use_put(h, 1, m);
     plat_mutex_unlock(&cache_lock);
@@ -1529,6 +1538,7 @@ static const GfxShader *translate_one(const Req *r, int stage, const uint8_t *co
         return fail(reply, hex);
     }
     // Not flushed (see "Durability" at the top): the translator wrote them whole, and disk_load checks both.
+    if (cache_flush()) plat_file_flush(spv_path), plat_file_flush(res_path);
     if (!(s = disk_load(key, r->iid))) return fail("translator output missing or malformed", hex);
     if (!r->final) {                                       // name the files after the cache key, remember the mask
         m = use_of(s);
@@ -1536,9 +1546,9 @@ static const GfxShader *translate_one(const Req *r, int stage, const uint8_t *co
         char mhex[65], to[PATH_CAP + 80];
         key_hex(mk, mhex);
         snprintf(to, PATH_CAP + 80, "%s/%s.spv", cache_dir, mhex);
-        int moved = plat_file_replace(spv_path, to, 0);
+        int moved = plat_file_replace(spv_path, to, cache_flush());
         snprintf(to, PATH_CAP + 80, "%s/%s.res.json", cache_dir, mhex);
-        moved = moved && plat_file_replace(res_path, to, 0);
+        moved = moved && plat_file_replace(res_path, to, cache_flush());
         if (moved) {
             use_store(r->code_hash, &m);
         } else {                                           // keep the mask for this run only