OT-ish SATA port replicators vs. SAS "expanders"

[Brandon Vincent]

On Sun, Nov 16, 2014 at 4:51 PM, Mike Tancsa <mike at sentex.net> wrote:
> I don think a port multiplier is the same as a SAS expander and a SAS/SATA
> controller does not necessarily support port multipliers.

You're absolutely correct. The SATA specifications if I recall
correctly, outline that providing support for port multipliers is
optional. Not to mention, the vast majority of chipsets that do have
support for port multipliers only provide the slower command-based
switching method [1], The LSI SAS 2008 chipset is not what you
typically find on the cheap consumer "fake RAID" cards which most
people have [2].

Most people who purchase this card are purchasing it for SAS, true
RAID, performance, and reliability. Thus, LSI is only going to provide
support for the far superior SAS expander technology.

Brandon Vincent

[1] https://www.sata-io.org/port-multipliers
[2] http://en.wikipedia.org/wiki/RAID#Firmware.2Fdriver-based