LSI 7102XP-LC, 7102XP-LC, 7102LXP-LC, 7202XP-LC, 7202LXP-LC, 7402XP-LC, 7202EP-LC, 7202EP, 7402EP-LC, 7402EP, 7202LXP-LC, 7402XP-LC, 7202EP-LC 3.4.2Adjusting Interrupt Coalescing

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.

3.4.2Adjusting 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) ∝ s. This means that the host is interrupted only once for 9 I/Os processed by the chip, unless 1280 ∝ s 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:

3-10	Firmware Installation Procedure