The following benchmarks have been performed on Fraunhofer Seislab, a test and experimental cluster at Fraunhofer ITWM with 25 nodes (20 compute + 5 storage) and a three tier memory: 1 TB RAM, 20 TB SSD, 120 TB HDD.
The nodes are equipped with 2x Intel Xeon X5660, 48 GB RAM, 4x Intel 510 Series SSD (RAID 0), Ext4, QDR Infiniband and run Scientific Linux 6.3, Kernel 2.6.32-279 and FhGFS 2012.10-beta1.