have here DSSV7 (lastest) running on a Dell R720 8c 3,3Ghz, 96GB memory, ESXi 7.0b.
There drives are Samsung 750GB SATA SSDs. The controller is a Dell PERC H710 Mini with batterie.
Have ran some benchmarks with Atto on a Win2016 VM (same image, moved between the datastores).
Results:
Same RAID5,
NFS Datastore: 60MB/sec-660MB/sec write, 69-927MB/sec read, avg. about 500MB/sec write, 700MB/sec read
iSCSI Datastore: 7-34MB/sec write, 54-684MB/sec read, avg. about 30MB/sec write, 600MB/sec read
If the logs show that the Array is currently "Write Back" and NOT "Write Through" and your getting these low results consider using another controller, those "Mini" 710's we have seen issues with performance. Even with the "Write Back" enable I have seen bad results from this controller, not worth investigating with the 710's especially the "Mini's".