RAM disk FAQ: clarify no perf benefit, add disable-cache tip; keep OS examples

Author: Devankguptaa

docs/cpp/faq-cpp.md

@@ -90,12 +90,19 @@ Yes. The C/C++ extension lets you relocate and limit the IntelliSense cache:
 - **`C_Cpp.intelliSenseCachePath`** — where the `ipch` cache is stored
 - **`C_Cpp.intelliSenseCacheSize`** — maximum cache size in MB (set to `0` to disable)
 
-By default, the cache lives under your user cache directory (Windows: `%LocalAppData%/Microsoft/vscode-cpptools`, Linux: `$XDG_CACHE_HOME/vscode-cpptools/` or `~/.cache/vscode-cpptools/`, macOS: `~/Library/Caches/vscode-cpptools/`). If you want to minimize SSD writes and speed up access, you can mount a RAM-backed filesystem and point the cache there.
+By default, the cache lives under your user cache directory (Windows: `%LocalAppData%/Microsoft/vscode-cpptools`, Linux: `$XDG_CACHE_HOME/vscode-cpptools/` or `~/.cache/vscode-cpptools/`, macOS: `~/Library/Caches/vscode-cpptools/`). If you want to minimize SSD writes, you can mount a RAM-backed filesystem and point the cache there.
+However, using a RAM disk does not generally improve IntelliSense performance and may increase memory usage, since the cache files are already memory-mapped by the IntelliSense processes.
 
 > **Notes**
 > - A RAM disk is volatile. The cache will be cleared on reboot/unmount (the cache will rebuild automatically).
 > - Set `C_Cpp.intelliSenseCacheSize` ≤ your RAM disk size.
 > - This is a per-user setting and works across all workspaces.
+> - If your main concern is reducing disk writes (e.g., SSD wear), you can also set `"C_Cpp.intelliSenseCacheSize": 0` to completely disable the cache instead of relocating it.
+
+> **Related:** The tag parser “browse” database path can be customized with
+> `"C_Cpp.default.browse.databaseFilename"`. Moving it to a RAM disk is generally not recommended for performance, but the path can be changed if needed.
+
+
 
 **macOS (APFS RAM disk, ~4 GB):**
 ```bash