SAS Expanders are a newer storage technology that lets you maximize the storage capability of your SAS controller card. Many SAS controllers support up to 128 hard drives. This can only be done with a SAS expander solution. Since many people are still unfamiliar with SAS Expansion, this site compares it to several storage technologies.
Why SAS Expanders?
- Single external multilane cable per enclosure.
- No adapters to convert internal ports to external.
- Can use the latest controllers and hard drives.
- Top speed with daisy chaining capability (see left pic).
However, the key difference... what happens after the 12th, 16th or 24th drive?
These charts show the pros & cons of expanders vs. other options:
more: Frequently Asked Questions (FAQ)
more: Serial Attached SCSI (wikipedia.org)
How Much Do They Cost?
Q: Are SAS Expanders more expensive than other storage technologies?
A: The enclosures are a bit more expensive; you save on everything else.
In many cases, the costs are comparable with other storage technologies,
while giving you more in terms of simplicity, flexibility and futureproofing.
SAS Expander Enclosures are now available in Tower, 2U, 3U and 4U.