Magma PCI Expansion System User Manual

For reasons described in bullet #3 above, we recommend using a fan-
out configuration when you need to add successive PCI expansion 
systems to the host computer. This addition to the PCI bus hierarchy is 
at the "peer" level of other existing expansion buses, thus adding 
"breadth" to the PCI bus hierarchy, since these buses will be at the 
same hierarchical level within the system configuration.  

 

You may use either PCIe or PCI host cards in your host 
computer, depending on available slots and your performance 
requirements. You must ensure that you have the 
corresponding PCIe to PCI Expansion System, or PCI 
Expansion System, chassis to connect with your host card and 
support your desired configuration. 

 

In this configuration, you have fewer “Toll Booths” (PCI Bridges) to pass 
through; therefore there are fewer opportunities for concern. 

 

For clarification, it is necessary to understand that the amount 
of latency caused by any PCI Bridge (even those built into a 3

rd

 

Party PCI card or the computer motherboard itself) is negligible 
(“nanoseconds”) and will not produce any visible effect on most 
systems. It is only mentioned here because on a few rare 
configurations which use some unique PCI cards with special 
software drivers, the total number of PCI buses that the data 
must pass through COULD make a difference. See 

 for more information if you suspect this could 

be an issue with one of your specialty PCI cards.