HP 640GB IO Accelerator BK836A
This storage device is targeted for markets & applications requiring high transaction rates and real-time data access that will benefit from application performance enhancement. The HP IO Accelerator brings high random I/O performance and low latency access to storage, with the reliability of solid state technology and its low power and cooling requirements. This product, based on NAND flash technology is available in a mezzanine card form factor for HP BladeSystem c-Class.
As an I/O card, the IO Accelerator is not a typical SSD; rather it is attached directly to the server's PCI Express fabric to offer extremely low latency and high bandwidth. The card is also designed to offer high IOPs (I/O Operations Per Second) and nearly symmetric read/write performance. The IO Accelerator uses a dedicated PCI Express x4 link with nearly 1.3GB/s of usable bandwidth
The HP IO Accelerator's driver and firmware provide a block-storage interface to the operating system that can easily be used in the place of legacy disk storage.
http://h20195.www2.hp.com/v2/GetPDF.aspx/c02010683.pdf
HP IO Accelerator Generation 1 devices include:
• AJ876A
• AJ877A
• AJ878A
• AJ878B
• BK836A
HP IO Accelerator Generation 2 devices include:
• QK761A
• QK762A
• QK763A
The Remote Power Cut Module provides a higher level of protection in the event of a catastrophic power loss (for example, a user accidentally pulls the wrong server blade out of the slot). The Remote Power Cut Module ensures in-flight writes are completed to NAND flash in these catastrophic scenarios. Write performance will degrade without the remote power cut module.
HP recommends attaching the remote power cut module for the AJ878B and BK836A SKUs.
IO and Read/Write Performance
HP IO Accelerator for BladeSystem c-Class offers superior IO performance (up to 530,000 IOPs), and high read (up to 1.5 GB/s) and write (up to 1.3 GB/s) performance with MLC models.
http://h18000.www1.hp.com/products/quickspecs/13220_na/13220_na.HTML
For AJ878B and BK836A Models
| 320GB | 640GB |
| NAND Type | MLC (Multi Level Cell) | MLC (Multi Level Cell) |
| Read Bandwidth (64kB) | 735 MB/s | 750 MB/s |
| Write Bandwidth (64kB) | 510 MB/s | 550 MB/s |
| Read IOPS (512 Byte) | 100,000 | 93,000 |
| Write IOPS (512 Byte) | 141,000 | 145,000 |
| Mixed IOPS (75/25 r/w) | 67,000 | 74,000 |
| Access Latency (512 Byte) | 30 µs | 30 µs |
| Bus Interface | PCI-Express x4 |
For QK761A, QK762A and QK763A Models
| 365GB | 785GB | 1.2 TB |
| NAND Type | MLC (Multi Level Cell) | MLC (Multi Level Cell) | MLC (Multi Level Cell) |
| Read Bandwidth (1MB) | 900 MB/s | 1.5 GB/s | 1.5 GB/s |
| Write Bandwidth (1MB) | 575 MB/s | 1.1 GB/s | 1.3 GB/s |
| Read IOPS (Seq. 512 Byte) | 415,000 | 443,000 | 443,000 |
| Write IOPS (Seq. 512 Byte) | 530,000 | 530,000 | 530,000 |
| Read IOPS (Rand. 512 Byte) | 136,000 | 141,000 | 143,000 |
| Write IOPS (Rand. 512 Byte) | 475,000 | 475,000 | 475,000 |
| Read Access Latency | 68µs | 68µs | 68µs |
| Write Access Latency | 15µs | 15µs | 15µs |
| Bus Interface | PCI-Express Gen2 x4 |
RAM RequirementsThe HP IO Accelerator drivers use RAM for fast access to the storage metadata. The amount of RAM required is a fraction of the actual storage in use. It is important to ensure that the driver will have free RAM available as storage usage is increased. The amount of free RAM required by the driver is directly related to the size of the blocks used when writing to the drive. When smaller blocks are used, RAM usage increases. Here are the guidelines for memory needed based on the capacity of IO Accelerator and the Block Size of the write:Average
average block size 512 bytes --- > Minimum System RAM requirement for 640GB Mezz IO Accelerator ( 23 GB )
