Avago Technologies LSI7104EP-LC - Manual (Page 54)

3-10 Firmware Installation Procedure
Ver. 2.1 Copyright © 2005-2006 by LSI Logic Corporation. All rights reserved.
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AUTO
•
1 Gbit/s
•
2 Gbit/s
•
4 Gbit/s
Step 3. Exit the FCUtil utility using the menu option q - Quit.
3.4.2 Adjusting Interrupt Coalescing
The LSI Logic host adapters can complete multiple I/O requests per host
interrupt. Interrupt coalescing is used to reduce CPU interrupts by
pooling multiple disk command completions (I/O) into one interrupt. This
feature may be enabled or disabled.
Important: LSI Logic has performed significant testing under multiple
I/O conditions, and has determined that interrupt
coalescing can be very valuable for small transfer lengths
or random, transaction-oriented I/O workloads. For this type
of workload, LSI Logic recommends that the Interrupt
Coalescing values be set to a queue depth of 9, with a
timeout of 1280 (0x500)
μs. This means that the host is
interrupted only once for 9 I/Os processed by the chip,
unless 1280
μs have passed since the host was last
interrupted. If the workload is of a large transfer length and
sequential, LSI Logic recommends that interrupt coalescing
be disabled, to prevent performance degradation.
Note: The LSI7204XP-LC has two FC ports and the
LSI7404XP-LC has four FC ports, so Interrupt Coalescing
must be configured for each port. The LSI7104XP-LC has
only one port.
Use the following procedure to adjust Interrupt Coalescing depth and
timeout values:
Step 1. To set the link speed of the host adapter, execute this command
from DOS:
A:\ Mptutil