Unified Serial RAID Controllers for PCIe

[Guest]

Storage vendors are unifying professional and semi-professional RAID controllers by supporting both SAS and SATA. We look at a set of products and their performance.

Unified Serial RAID Controllers for PCIe : Read more

 

[Rik]

...well,
- Unless RaidCore is trying to peddle their VST Pro software,...aka as Fulcrum proprietary based ? which BTW you said no to, I don't see any advantages here.
Why?, ZFS is free !
And, where are the Drives for Solaris, or the xBSD's , or even MacOSX !!!?
-and still no, becuase their newer 54xx series doesn't support the other 'ix OS's.
Nope, unfortunately, not much to see here.
so, based on the above, Adaptec 5805,... or Areca,... blows this.

-Rikster

 

[aapocketz]

For SAS, the two connector segments were merged, which makes it possible to attach a SAS drive to a SATA controller using the continuous connector, but you cannot hook up a SAS hard drive to a SATA controller using the SATA connector (SFF 8482).

I think this paragraph has an error. I believe it should read

For SAS, the two connector segments were merged, which makes it possible to attach a SATA drive to a SAS controller using the continuous connector, but you cannot hook up a SAS hard drive to a SATA controller using the SATA connector (SFF 8482).

In fact I believe the statement should have less emphasis on the connector as its the actual controller that appears to limit the connectivity, the connector is just keyed to allow you to plug SATA drives into SAS but not the other way around.

from wikipedia: "SATA 3.0 Gbit/s drives may be connected to SAS backplanes, but SAS drives may not be connected to SATA backplanes."

I believe the fact that signaling voltages are nearly double on a SAS drive is significant to mention.

Let me know if I am wrong, I just started playing around with a bunch of SAS drives so I am figuring this out as I go.

 

[Guest]

Factors like spindle speed, density, latency etc. effects drive performance as much or more than bandwidth. A 300GB 2.5 15K SAS drive will smoke a 1TB 7200 SATA drive simply because it has about twice the IOPS. The bandwidth is meaningless if you can't get the data on and off the disk at the speed of the bus. Furthermore, except for the WD Velociraptor 10K+ spindle speed drives are non-existent in SATA but are prevalent in SAS. So from an interface standpoint they are very close but SAS drives are really intended for entirely different markets and applications and budgets I might add.

 

[Bicom Systems]

Great article - thanks for the comparison! We also did a piece on SAS and SATA, if you're interested : http://blog.bicomsystems.com/sas-vs-sata