Benefits of Host Bus Adapter

1
Benefits of Host Bus Adaptar
Buffer is a memory storage to temporarily hold
data. To transfer data from different devices
this memory portion is used
2
What is host bus adapter
Host bus adapter is a circuit board or integrated
circuit adapter it provides I/O processing
between physically connected devices. It uses a
microprocessor for storage and retrieving of
data. It has associated disk subsystem it
sometimes called disk channel.
3
Benefits of HBA data buffer

• Need for data buffering.
• Credit of buffer.
• Calculate the credit requirement.
• Fibre channel architecture.
• Hardware context cache.
• Performance benefits.

4
Need for data buffering
Application like remote backup wide campus SAN
movement of high bandwidth data over extended
distance. Key enabler to improve the high
distance is the buffer of HBA. System with heavy
loaded PCI bus also benefitted from buffer HBA.
5
Credit Buffer
In the Fibre channel data is organized in a
frame. Size depends on 512 bytes to 2 KB. Using
buffer credit mechanism it can transfer maximum
amount of data. It deliver significantly high
performance in the lower CPU overhead.
6
Calculate the credit requirement
We can calculate the credit easily. Light
travelling 5 ns so the round trip latency of data
10 km fiber optic cable in 100 milliseconds.
Multiple frame must be fully utilized the link
benefit. When it operating 2 Gbps instead of 1
Gbps then twice the buffer credit needed to fully
utilized the bandwidth.
7
Fibre channel architecture
HBA with large data buffer maintains high
throughput over long distance. Other performance
is impacted due to its limited number of frames
buffers. In long distance like 10 km it provides
more than twice performance than HBA without
large buffer.
8
Hardware context cache
When HBA initiates I/O command it stores
information to uniquely identifying command. This
information is called context information it must
be correctly match to the I/O command. When data
returned from I/O command to the HBA it must also
be matched with context info.
9
Performance Benefit
HBA dramaticaly limit the performance in the
switched febric SAN. Under the I/O febric load it
maintains the high throughput. In the switch
febric environment its hardware context switch
provides more than twice performance.
10
Advantage of Host Bus Adaptar
HBA provides performance advantage using the
feature of hardware context and large data
buffer. In the higher bandwidth performance
hardware context cache maintains high
performance. It has the ability to increase link
data rate. Example of this type of bus is Sun
SG-XPCIE2FC-QF4 PCI Express Host Bus Adapters
11
Contact Details
188-M Technology Drive  Irvine CA 92618 Tel
[phone]  Fax [phone] www.shoprico
m.com
12
(No Transcript)