Q-Logic Computer Drive IB0056101-00 G Benutzerhandbuch

4 – Hardware Installation
Hardware Installation Requirements

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The QLogic adapter also supports connection to the switch by means of optical 
fibres through optical media converters such as the EMCORE™ QT2400. Not all 
switches support these types of convertors. For more information on the 
EMCORE convertor, see 

Intel

®

 and Zarlink™ also offer optical cable solutions. See 

 and 

 for more information.

To achieve the best performance with QLogic adapters, you need to configure 
your BIOS with specific settings. The BIOS settings, which are stored in 
non-volatile memory, contain certain parameters characterizing the system. These 
parameters may include date and time, configuration settings, and information 
about the installed hardware.

There are two issues concerning BIOS settings of which you need to be aware:

„

Advanced Configuration and Power Interface (ACPI) needs to be enabled.

„

Memory Type Range Registers (MTRR) mapping needs to be set to 
“Discrete”.

MTRR is used by the InfiniPath driver to enable write combining to the on-chip 
transmit buffers. This option improves write bandwidth to the QLogic chip by 
writing multiple words in a single bus transaction (typically 64 bytes). This option 
applies only to x86_64 systems.

However, some BIOS’ do not have the MTRR mapping option. It may have a 
different name, depending on the chipset, vendor, BIOS, or other factors. For 
example, it is sometimes referred to as 32 bit memory hole, which must be 
enabled. 

You can check and adjust these BIOS settings using the BIOS Setup utility. For 
specific instructions, follow the hardware documentation that came with your 
system.

QLogic also provides a script, ipath_mtrr, which sets the MTRR registers. 

These registers enable maximum performance from the InfiniPath driver. This 
script can be run after the InfiniPath software has been installed. It needs to be 
run after each system reboot.

For more details, see 

.