Magma PCI Expansion System User Manual

 

2.  The 4 and 7 Slot Magma Expansion Systems each add two (2) 

PCI to PCI Bridges to the PCI Local Bus. The 13 Slot adds 
three (3) PCI to PCI Bridges to the PCI Local Bus. The PE6R4t 
adds one (1) bridge. These bridges are the communication 
paths between the PCI cards and the computer resources. 
Most computers allow multiple bridges (and thus PCI buses) to 
be correctly configured. Some computers, unfortunately, place 
an arbitrary limit on the number of bridge levels that can be 
traveled during power-on configuration. Your computer “power-
on-software” should be PCI Specification 2.1 compliant in order 
to effectively use a Magma PCI Expansion System. For "fan-
out" and "daisy chained" system configurations, where more 
than one PCI expansion system is being used, you should 
count all of the bridge levels to your most deeply nested PCI 
bus to determine the maximum number of bridge levels that 
must be traveled.  

3.  For easier understanding, the PCI Local Bus should be viewed 

as a “Resource Toll road” that runs from the computer CPU 
(resource home), through the “Toll Booths” (the PCI bridges), 
to the “Resource Users” (PCI Cards). As in the case of a real 
Toll Road, the more Toll Booths you have to slow down a 
“nanosecond” for, the longer it will take you (your data) to get 
from the PCI Card to the CPU and back again. Under most 
circumstances the effect cannot even be detected. However, 
under other conditions, it can be important to know about.