Add information about RAM speed for `Barnard`

doc.zih.tu-dresden.de/docs/jobs_and_resources/hardware_overview.md

@@ -110,7 +110,7 @@ CPUs.
 
 - 630 nodes, each with
     - 2 x Intel Xeon Platinum 8470 (52 cores) @ 2.00 GHz, Multithreading enabled
-    - 512 GB RAM
+    - 512 GB RAM (8 x 32 GB DDR5-4800 MT/s per socket)
     - 12 nodes provide 1.8 TB local storage on NVMe device at `/tmp`
     - All other nodes are diskless and have no or very limited local storage (i.e. `/tmp`)
 - Login nodes: `login[1-4].barnard.hpc.tu-dresden.de`