Asset ID:	1-71-1002058.1
Update Date:	2009-12-22
Keywords:

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Solution Type  Technical Instruction Sure

Solution  1002058.1 :   Sun Ultra/Enterprise[TM] Servers: Avoiding Bottlenecks on SBUS I/O Boards  


PreviouslyPublishedAs
202897

Description
This document tells you how to avoid I/O bottlenecks in the Enterprise 3x00-6500 systems to prevent poor performance in I/O.


Steps to Follow
When installing SBUS cards in an Enterprise server, you must load balance for throughput. The layout on the SBUS I/O board has two SYSIO channels with a maximum throughput of 120Mbyte.

SYSIO-0 is the through point for SBUS SLOT 1, 2 and the onboard Fiber controller. SYSIO-1 is the through point for SBUS 0, onboard SCSI and the onboard network port. The bandwidth for each SYSIO chip is 120Mbyte each, which is important to understand when installing cards. You will want to load balance your installation for throughput. For example, if you are using the onboard fiber ports and want to install a SBUS Fiber card, install the card in SBUS slot 0 to avoid contention with the onboard fiber.

Each SBUS has a maximum throughput of 100Mbyte ((25MHz * 32bit)/8); 25MHz is the bus frequency, 32 bit is the SBUS bus, and then dividing by 8 to convert to bytes. The channel to the SYSIO is 120Mbyte, so if each card can supply 100Mbyte the bus can saturate quickly.

You will notice a degradation in performance during peak usage, backups, or with online transactions, which rely heavily on the database through the controllers.

Backpanel and Connectors

Refer to Figure 1.

Product
Sun Enterprise 4000 Server
Sun Enterprise 3000 Server
Sun Enterprise 3500 Server
Sun Enterprise 6500 Server
Sun Enterprise 5500 Server
Sun Enterprise 4500 Server

Internal Comments
Place Sun Internal-Use Only content here. This content will be published to internal SunSolve only.

Previously Published As
75083

Change History
Date: 2007-05-09
User Name: T209852
Action: Approved
Comment: Moved 1 text image as attachment in preparation for IBIS migration.
Version: 3
Product_uuid
29ba62b0-0a18-11d6-8988-8f3c2795672c|Sun Enterprise 4000 Server
29b0cfe8-0a18-11d6-94a5-e63f070c91a4|Sun Enterprise 3000 Server
29b720d2-0a18-11d6-9865-e60ab6457390|Sun Enterprise 3500 Server
29ccbffa-0a18-11d6-944e-9f2643ef1cd7|Sun Enterprise 6500 Server
29c606ce-0a18-11d6-98c8-de563f7f1f97|Sun Enterprise 5500 Server
29bdb91a-0a18-11d6-9d2c-c8c4d893e741|Sun Enterprise 4500 Server

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