HP PCIe IO Accelerators for ProLiant Servers - Manual (Page 11)

Introduction 11
* The fio-format utility automatically formats the device to this block size unless specified differently.
You can reduce memory use by selecting a 4K sector size, forcing the average written block size to be 4K
or greater. For most systems, even when formatted with 512 byte sectors, actual memory use typically
tracks 4K or greater average I/O size.
The HP IO Accelerator Duo requires a PCIe Gen1 x8 slot or a PCIe Gen2 x4 slot. For maximum
performance, HP recommends that an external power source be connected to the IO Accelerator Duo,
through the Duo external power supply connector. If the external power supply connector is not used, the
PCIe slot holding the Duo must be capable of providing a power requirement of at least 25 watts. The
Duo power-throttles to an average of 25 watts to meet the 25-watt requirement of the PCIe slot when the
external power connector is not used. This power throttling might cause slower performance with the Duo.