Magma PCIHIF68 Instrukcja Użytkownika Pobierz pdf (Strona 8)

Media 100 Legacy Compatible Peripherals Guide

▼

Technical Notes

This section addresses issues found with CPUs and Disk Drive Controllers, including

■

“Slowing Synchronous Transfer Rates” on page 8

■

“Ultra SCSI and Older 3-slot Systems” on page 10

■

“RAM Issues” on page 10

■

“Power Computing Clones” on page 11

Slowing Synchronous Transfer Rates

With Media 100

in a dual-monitor conﬁguration, Media 100 has found that the high speed of

Low Voltage Differential (LVD) SCSI controllers at full speed (80 MB/second) can monopolize

the limited PCI bandwidth in a blue and white G3 or G4 computer, and in so doing may cause

performance problems at high data rates. To prevent these issues, slow down the transfer rate of

this system in a blue and white G3 or G4 computer. By slowing down the transfer rate to 20 MB/

second, you can still achieve data rates up to 300 KB/frame NTSC and 360 KB/frame PAL.

Customers with Media 100

through

systems may need to perform this procedure if they

encounter persistent bad video frames in a blue and white G3 or G4 computer.

The following two sections outline the steps required to slow down the synchronous transfer rates

of the Adaptec 2940U2B or 2940U2W and ATTO ExpressPCI UL2S SCSI controllers.

Adaptec 2940U2B and 2940U2W SCSI Controllers

Version 5.1 of Adaptec PowerDomain Control utility is required to slow down the synchronous

transfer rate of the Adaptec 2940U2B or 2940U2W SCSI controller. This software is available for

download from Adaptec at ftp://ftp.adaptec.com/pub/BBS/PowerMac.

o slow down the transfer rate of the Adaptec 2940U2B or 2940U2W

Launch the Power Domain Control utility.

In the Select a SCSI Bus window, select the Power Domain card.

At the bottom of the PowerDomain Control window, select the Advanced tab.

In the Advanced section, drag the SCSI Mode slider to Fast-SCSI and release.

Click Set at the top right of the PowerDomain Control window.

Quit the PowerDomain Control utility.

Restart the computer to effect the changes.

Media 100 recommends that you leave the other settings for the PowerDomain SCSI controller at their

defaults: “Termination” at “Automatic” and “PCI Bus Mode” at “Immediate.”

1 2 3 4 5 6 7 8 9 10 11 12 13 ... 59 60

Brak uwag

Magma PCIHIF68 Instrukcja Użytkownika Strona 8