What are the differences between the Legacy 5018 adapter cards and OSS-HIB68-x16?

[One Stop Systems]

Product: OSS-HIB68-x16 cards and Legacy 00-5018-00 board (this was made by Magma)

Question:

What are the differences between the Magma 5018 adapter cards and OSS-HIB68-x16?

Answer:

The Magma 5018 adapter cards and HIB38 boards use different technology that effects the jitter properties of the channel. 
•  The 5018 board uses a redriver technology while the HIB38 board uses a PCIe switch technology.
•  One of the key parameters in the reliability of a PCIe link is the jitter of the received signal.
•  This is a combination of the output jitter from source and various channel effects such as long traces, connectors and cabling.
•  The longer the distance from the source to the receiver the worse the jitter becomes.

Using a 5018 redriver technology does not do anything to compensate for longer distances that are typically found with cabling solutions. 

The output jitter from the host computer is compounded in an additive way and can be high enough to not allow PCIe linkage.
The HIB68 device uses switch technology which basically resets the jitter budget so that longer channels can be used.

So the jitter starts at the host computer, then compounds to the PCIe switch. 

The jitter budget is reset on the HIB68 card for the cable transmission and reset again at the expansion chassis HIB38 card for the expansion board transmission. 

So, in the HIB38 case, the jitter budget is reset two times in the channel where in the redriver case the jitter budget is never reset