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+What performance should I expect from your SAS systems?
SAS is a very high performance link and our enclosures are typically transparent in performance terms. For hard drive setups, the performance bottleneck is going to be the number of hard drives in the system (the more HDs, the faster the system) up to the point where you saturate the RAID controller or the SAS link at 4800MB/sec. Performance scales almost linearly with the first set of 12 drives, giving you well over 1000MB/sec even in RAID6, with the curve slowly flattening as you add more and more drives. SSDs will scale much faster.
+What's the difference between ``direct-connect`` and ``expander`` JBODs?
Direct-connect JBODs do not have expanders built in and mostly passive devices. The connection is one-to-one mapped, that is each port on the controller card connects directly to a hard drive. Each SAS cable supports 4 drives. For example, if you have an 8-port, dual connector controller card, you can attach this to an 8-drive direct-connect JBOD and no daisy-chaining is possible. Expander modules overcome this limitation.

In addition, SES2 enclosure services require an expander module. Without an expander, disk locator and failure LEDs aren’t supported and the controller card will not receive monitoring information from the enclosure such as failure reports or fan speeds and internal temperatures.

+Will your systems work with SATA drives?
Yes. There are a couple of exceptions however:

1-We don’t support the use of low-RPM power saving desktop drives. While such drives tend to work fine, timeouts are possible.
2-Our dual expander and dual RAID controller systems ideally require the use of SAS drives. SATA drives will require the purchase of interposer boards to make them work. We don’t support desktop drives with these systems.

+What RAID controller and HBAs do you recommend?
We recommend LSI or Areca RAID controllers and HBAs. In particular the models LSI 9300-8e, 9380-8e and Areca 1883X.