HP B- Accelerators Linux manual Introduction

•Sufficient RAM to operate—The amount of RAM that the driver requires to manage the NAND flash varies according to the block size you select when formatting the device (filesystem format, not low-level format). For a virtual machine using an IO Accelerator directly (using PCI pass-through), consult the user guide for the installed operating system. The following table lists the amount of RAM required per 100GB of storage space, using various block sizes. The amount of RAM used in driver version 3.0 is significantly less than the amount used in version 1.2.x.

Average block size	RAM usage for each 80	RAM usage for each 100	Minimum system RAM
(bytes)	GB IO Accelerator	GB IO Accelerator	requirement for 320 GB
	(Megabytes)	(Megabytes)	MezzIO Accelerator*
8,192	250	280	1 GB
4,096	400	530	1.6 GB
2,048	750	1,030	3 GB
1,024	1,450	2,000	5.8 GB
512	2,850	3,970	11.4 GB

Average block size	Minimum system RAM	Minimum system RAM	Minimum system RAM
(bytes)	requirement for 640 GB	requirement for 785 GB	requirement for 1.2 TB
	MezzIO Accelerator*	MezzIO Accelerator*	MezzIO Accelerator*
8,192	2 GB	2.2 GB	3.4 GB
4,096	3.2 GB	4.2 GB	6.4 GB
2,048	6 GB	8.1 GB	12.4 GB
1,024	11.6 GB	15.7 GB	24 GB
512	22.8 GB	31.2 GB	47.6 GB

*For IO Accelerator use only. Additional RAM is needed for system operating system and applications.

HP PCIe IO Accelerator Duo requirements

In addition to the IO Accelerator cooling and RAM requirements listed in the previous table, the IO Accelerator Duo requires at least:

•A PCIe Gen1 x8 slot or a PCIe Gen2 x4 slot

•A minimum of a full-height, half-length slot with a x8 physical connection. For systems with PCI 1.1, all eight signaling lanes must be active for full IO Accelerator Duo performance. For systems with PCIe 2.0, only four signaling lanes must be active for full performance.

NOTE: With driver version 3.1.0 and later, the driver detects in the BIOS if the PCIe slot supports a 75W power draw. If the slot supports up to 75W, the IO Accelerator device draws up to that amount of power. However, if an external power cable is used, power is only supplied by that cable.

To verify whether a slot is supplying 75W, view the system logs or use the fio-pci-checkutility.

Introduction 11