System information

however, as APIC-enabled motherboards turn IRQ control over to the operating
system.
• Server-class motherboards generally implement a different PCI standard than
workstation-class motherboards. While there are many differences, the most ob-
vious and well known is that the two versions have different voltages. Depending
on which cards you purchase, you will need to know if you require 3.3V or 5V PCI
slots.
‖
Figure C-1 shows the visual differences between 3.3V and 5V slots. Most
server motherboards will have both types, but workstations will typically have only
the 5V version.
There is some evidence that suggests connecting together two com-
pletely separate, single-CPU systems may provide far more benefits
than simply using two processors in the same machine. You not
only double your CPU power, but you also achieve a much better
level of redundancy at a similar cost to a single-chassis, dual-CPU
machine. Keep in mind, though, that a dual-server Asterisk solu-
tion will be more complex to design than a single-machine solution.
Figure C-1. Visual identification of PCI slots
• Consider using multiple processors, or processors with multiple cores. This will
provide an improvement in the system’s ability to handle multiple tasks. For
Asterisk, this will be of special benefit in the area of floating-point operations.
‖ With the advent of PCI-X and PCI-Express, it is becoming harder and harder to select a motherboard with
the correct type of slots. Be very certain that the motherboard you select has the correct type and quantity of
card slots for your hardware. Keep in mind that most companies that produce hardware cards for Asterisk
offer PCI and PCI-Express versions, but it’s still up to you to make sure they make sense in whatever
motherboard and chassis combination you choose.
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