User's Manual

3-10 Firmware Installation Procedure

g - Toggle Board Speed on Function 1

Successively pressing the F key (for Function 0) or the G key

(for Function 1) toggles the PORT speed setting between these

three modes:

• AUTO

• 1 Gbit/s

• 2 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 LSI7202XP-LC, LSI7202EP-LC, and LSI7202EP each

have two FC ports and the LSI7402XP-LC, LSI7402XP-LC,

and LSI7402XP-LC each have four FC ports, so Interrupt

Coalescing must be conﬁgured for each port. The

LSI7102XP-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 the DOS command line: