Can LSISAS1068E chip be configured as a x8 wide port?

Can LSISAS1068E chip be configured as a x8 wide port?

[wenshuang.ma]

Hi,

LSISAS1068E is a 2 ports(total 8 PHY) SAS controller with per port can be 
configured as a 4 PHY SAS wide port,with the usage of arbitrary one
port LSISAS1068E can control a SAS expander through a MiniSASx4 to 
SASx4 cable,we get 4 connections simultaneously.Is it possible for 
LSISAS1068E to control one SAS expander through two MiniSASx4 to SASx4
cables so we can have 8 connections simultaneously(more bandwidth)
if not,why? 

Thanks
Wenshuang
 				

Re: Can LSISAS1068E chip be configured as a x8 wide port?

[Douglas Gilbert]

wenshuang.ma wrote:
> Hi,
> 
> LSISAS1068E is a 2 ports(total 8 PHY) SAS controller with per port can be 
> configured as a 4 PHY SAS wide port,with the usage of arbitrary one
> port LSISAS1068E can control a SAS expander through a MiniSASx4 to 
> SASx4 cable,we get 4 connections simultaneously.Is it possible for 
> LSISAS1068E to control one SAS expander through two MiniSASx4 to SASx4
> cables so we can have 8 connections simultaneously(more bandwidth)
> if not,why? 

During my experiments I tried something like that
and couldn't get a wide port wider than 4 phys.

I think the reason was that each group of 4 phys
has a different initiator port identifier (SAS
address) seen from the expander. You could check
that with smp_discover (in my smp_utils package).
Or perhaps there was another reason (e.g. perhaps
the expander didn't support it). It didn't work
anyway.

Can LSI's SAS-2 chips do 8 (phy) wide ports?


Note: What SCSI/SAS calls a "port" and LSI's usage
of that term is a bit different. For example you
want two "LSI" ports to act as one SCSI port.

Doug Gilbert