Should I use a 1x or 4x SAS cable?
 

I'm installing SATA drives in an external SAS enclosure. The
enclosure is connected to a LSI Logic MegaRAID 8888ELP RAID card.

My question is, what advantage will a 4x SAS cable connecting the RAID
card to the enclosure give me over a 1x cable? And does it matter
that the drives are SATA vs. SAS?

Thanks,

Ryan

Should I use a 1x or 4x SAS cable?
 

On Jun 13, 12:48 pm, Ryan408 wrote:
I'm installing SATA drives in an external SAS enclosure. The
enclosure is connected to a LSI Logic MegaRAID 8888ELP RAID card.

My question is, what advantage will a 4x SAS cable connecting the RAID
card to the enclosure give me over a 1x cable? And does it matter
that the drives are SATA vs. SAS?

Although connecting a SATA drive to a SAS enclosure will work, you
won't get the benefits of a SAS drive. SATA drives are typically
bigger but slower (and cheaper). They can't read and write at the
same time - the SATA bus is unidirectional. Although I haven't tested
this, I believe that a 4x cable will not give you any benefit over a
1x cable - SATA is only 1-phy.

.../Ed

--
Ed Wilts, Mounds View, MN, USA
RHCE, BCFP, BCSD, SCSP, SCSE


If I've helped you, please make a donation to my favorite charity at
http://firstgiving.com/edwilts

Should I use a 1x or 4x SAS cable?
 

Although I haven't tested
this, I believe that a 4x cable will not give you any benefit over a
1x cable - SATA is only 1-phy.


SATA drives are single-ported, while some SAS drives are dual-ported.
However, there are no quad-port SAS drives so why the 4x cable?

I don't think the correlation is between SAS lanes and ports on the
drive.

Ryan

Should I use a 1x or 4x SAS cable?
 

Ryan408 wrote:
Although I haven't tested
this, I believe that a 4x cable will not give you any benefit over a
1x cable - SATA is only 1-phy.


SATA drives are single-ported, while some SAS drives are dual-ported.
However, there are no quad-port SAS drives so why the 4x cable?

To provide a separate SATA channel to each drive? With a 1x cable
wouldn't I/O requests for all four drives have to share the same link.


--
Nik Simpson

Should I use a 1x or 4x SAS cable?
 

On Jun 13, 1:09*pm, nik Simpson wrote:
Ryan408 wrote:
* Although I haven't tested
this, I believe that a 4x cable will not give you any benefit over a
1x cable - SATA is only 1-phy.

SATA drives are single-ported, while some SAS drives are dual-ported.
However, there are no quad-port SAS drives so why the 4x cable?

To provide a separate SATA channel to each drive? With a 1x cable
wouldn't I/O requests for all four drives have to share the same link.

--
Nik Simpson

A well designed controller should be able to do exactly that. Each
port should
be able to concurrently talk to a separate disk drive. I have no idea
if the LSI card
mentioned above does that though. Maybe someone else knows.

Dave