Re: Looking for FOSS supported PCIe x4 SATA 6 Gb/s HBA with 4 or 8 ports

[David Christensen <dpchrist@holgerdanske.com>]

> > Looking at Wikipedia, PCI Express link performance table:
> >
> > https://en.wikipedia.org/wiki/PCI_Express#History_and_revisions
> >
> >
> > I believe 2.5 GT/s produces 2.5 Gb/s under PCIe version 1.0.  So, the Syba
> > specification is correct in this case.
>
> They apparently conflated "GT/sec" and "Gb/sec" (uhh, "conflated" might
> be the wrong word).  2.5 GT / sec with an 8/10 encoding scheme, while
> "yes" 2.5 gbit worth of data is being transmitted, results in only 2000
> mbit (2.0 gbit) of usable data.  The other 500 mbit being eaten by the
> overhead.


2000 Mb/s / (8 b/B) = 250 MB/s


which matches the Wikipedia throughput value.


> But yeah, I guess this isn't anything more than sidebar to your initial
> question :|.  I'll have to dig up what cards I've used in the past (been
> a long time since I've had a desktop ... last two PCs have been
> laptops).

Okay.


David