Curious what you are using to generate load.
I am getting the following on a FAS3050. The throughput I've seen on FAS32xx series is at least double.
stats show -i 1 -n 10 volume:mail08a
Instance avg_latency total_ops read_data read_latency read_ops write_data write_latenc write_ops other_latenc other_ops
ms /s b/s ms /s b/s ms /s ms /s
vola 7.21 1766 1095921 10.28 59 259546 1.20 43 7.26 1664
vola 6.21 1957 513024 7.87 48 6074326 0.70 218 6.88 1691
vola 6.86 1915 1908548 9.16 80 154325 0.13 43 6.92 1792
vola 11.02 1525 6833587 11.35 253 215398 4.13 30 11.11 1242
vola 8.45 2297 11811749 10.18 414 248801 1.32 50 8.25 1833
vola 7.47 1935 12898086 8.08 451 57566 0.74 43 7.49 1441
vola 6.87 1651 792562 6.37 54 191804 1.02 48 7.07 1549
vola 7.29 1848 1430759 6.94 71 488807 0.55 58 7.53 1719
vola 8.30 1609 3471909 6.47 127 142184 1.17 39 8.65 1443
vola 7.29 1377 914089 8.03 63 127162 0.71 38 7.46 1276