LinuxPlanet: Emulex Connects To Linux
Aug 09, 2004, 19:45 (0 Talkback[s])
(Other stories by Rob Reilly)
"Connecting an application server to a corporate network, via a
NIC, has its drawbacks. The main problem is that more than 50% of
the server's CPU can be consumed processing small-block
"An HBA (host bus adapter) can offload that I/O and return those
lost CPU cycles to the task of processing transactions, by the
server. It does this in three different ways:
- "The high performance microprocessors in the HBA manage the
- "The HBA controls DMA (direct memory access) of the data to the
host server. This offloads that task from the server CPU.
- "Finally, the HBA can batch process CPU interrupts, instead of
doing them one at a time.
"Large scale, high speed transaction and storage processing I/O
is what HBAs are all about. Typical transfer rates are in the
neighborhood of 2 Gb/s..."