When googling 'SAS vs SATA' and the like, you get a lot of results that imply or directly state that SAS drives are always faster and always more reliable than SATA drives.
Honestly, I doubt this. I've never worked in a professional server environment, but SAS seems to be outdated - looking on Amazon, Google or eBay for SAS drives results in seeing things manufactured in 2015.
Similarly, I have a poweredge r720. I've just ordered some WD Gold drives - I'm not looking for a product recommendation, but can someone explain why, according to those guides, the WD gold drives would be vastly inferior to any SAS.
Maybe the reason I'm seeing old drives is because I only need small capacity drives - 4 TB, which SAS drives could've passed years ago. Unfortunately I just don't know, as my perception of the market is not accurate without actually being a part of it.
2 Answers
I work with these daily.
When googling 'SAS vs SATA' and the like, you get a lot of results that imply or directly state that SAS drives are always faster and always more reliable than SATA drives.
SATA-III drives are capped at a theoretical output of 600 MB/sec or 6 Gb/sec.
SAS-3 drives are capped at a theoretical output of 12 Gb/sec, and SAS-4 drives will peak at 22.5 Gb/sec. SAS faster? Yes, but not by much. Only server farm operators care enough to buy the spendier SAS drives, which BTW require a SAS capable controller.
More reliable? Well, SAS drives, being server-only, are built to a higher spec than your consumer grade SATA drive,, but a SATA-III server drive should not be any less reliable than a server-grade SAS drive.
Honestly, I doubt this. I've never worked in a professional server environment, but SAS seems to be outdated - looking on Amazon, Google or eBay for SAS drives results in seeing things manufactured in 2015.
Yep. SAS drives don't sell as rapidly as SATA-III, since they won't work in a desktop PC unless a special controller is added.
Similarly, I have a Poweredge R720. I've just ordered some WD Gold drives - I'm not looking for a product recommendation, but can someone explain why, according to those guides, the WD gold drives would be vastly inferior to any SAS.
I won't say SAS is vastly superior. Now, that server also supports PCIe drives, which are vastly superior.
Maybe the reason I'm seeing old drives is because I only need small capacity drives - 4 TB, which SAS drives could've passed years ago. Unfortunately I just don't know, as my perception of the market is not accurate without actually being a part of it.
SAS drives are getting lost in the dust of PCIe/MVMe drives for servers, which are far superior. Now that PCI-e NVMe drives and adapters for them have gotten cheap, folks who want performance go NVMe, which beats both SAS-4 (if those drives ever reach the marketplace) and SATA-III.
5Just because the connection itself allows for a certain speed maximum, doesn't mean that it isn't being bottlenecked by the drive itself or whatever (same with anything else, like PCIe). Even with SATA3 - even though the max is 600mb/s, most HDDs work in the 200-300mb/s range, while SAS connected drives, I assume, are very similar drives spinning the same 5400-15000rpm so the speeds are roughly the same per drive assuming the rpms are the same. I guess SAS was mostly oriented for raids and faster rpms. SATA3 is fine as long as it isn't bottlenecking, for example it is used in (isn't bottlenecking) even the slower SSDs - working at 500mb/s.
