Issue 187612: Chapter 7.External Memory Interfaces in Stratix V Devices (.PDF) (ver 2014.01.10, Jan 2014, 532 KB)
Table 7-2 shows External Memory Interface Performance in Stratix® V Devices. It states that the soft controller can support 933MHz DDR3 SDRAM with 1.35V (DDR3L). This statement is incorrect. The maximum performance for DDR3L is 800MHz . You can find more information about DDR3 performance from External Memory Interface Spec Estimator.