Why are sas drives faster?

[Proprietary]

Why are sas drives said to rotate faster? Isn’t sas just a transfer interface (serial attached scsi)? If so, why does it affect the rotational speed and the reliability of the drive itself?

[scottyseng]

SAS is just a transfer interface, yes. It's just that SAS is considered an enterprise level feature so usually the drives are ranked to stricter standards / faster RPM drives since consumers would never want such loud and hot drives.

 

You can find SAS drives in normal 7,200 RPM as well.

[Syntaxvgm]

Rotate faster? Fast mechanical drives exist for both SAS and sata. Drives that are like 10k rpm are largely useless now, as their purpose was to provide faster access and somewhat faster randoms, at least as fast as you could get with spinning rust. They were loud, ran hot, and cost more for less capacity. They've mostly been replaced with flash storage these days for anything that requires fast access. The drive itself isn't largely different, just the board on the drive. 

If you're looking for like raid controllers with more advanced features and better diagnostic data, you're probably looking at a SAS card (not that there isn't good sata solutions out there). A sas controller can support multiple data lanes, and the total throughput I think is 12Gb/s, faster than sata but it's not like you're going to saturate that with one mechanical drive- and it's only with enterprise solutions you're likely to see shit like port multipliers and sas expanders. Oh, and SAS supports sata, but not the other way around. It actually gets really confusing on what can do what when it comes to server mass storage solutions. It's really not something you should concern yourself with unless you are looking for just a few drives. 

 

There's some other unique reasons for SAS (like the long max cable length, 10m if you want a jump rope), but to be honest if you don't know them you're probably not in a position to even consider it, and since it's mostly server/enterprise solutions, it often costs more and is less user friendly/well documented. The drive itself is not defined by the connector really, and while you'll generally see faster and more reliable drives with sas, that's simply because no one is using SAS in the consumer market- pretty much all of the drives are enterprise grade. These days you'll see some high end drives that come in both sas or sata are basically the same drive. In the end it's still just a hard rive, though likely more often enterprise grade. Just choose whatever's more convenient for you, and SAS probably only is if you're working with something that already has it- like raid cards or servers people like to scoop up off ebay for cheap is where I see people have to deal with it that have no experience with it. 

[Proprietary]

20 minutes ago, scottyseng said:

SAS is just a transfer interface, yes. It's just that SAS is considered an enterprise level feature so usually the drives are ranked to stricter standards / faster RPM drives since consumers would never want such loud and hot drives.

 

You can find SAS drives in normal 7,200 RPM as well.

Oh thanks. Where can I find some relatively cheap, but new sas hard drives? Amazon/ebay/Newegg didn’t offer too many options...

[Electronics Wizardy]

Just now, Proprietary said:

Oh thanks. Where can I find some relatively cheap, but new sas hard drives? Amazon/ebay/Newegg didn’t offer too many options...

why do you want sas hdds? Do you want multipath? They work basically the same as sata hdds.

 

If you want a new drive you gonna want something like the seagate exos or the wd hgst ultrastar drives.

[Proprietary]

13 minutes ago, Electronics Wizardy said:

why do you want sas hdds?

Honestly... just to make my server more server-ish... don’t most servers use sas drives?

[scottyseng]

28 minutes ago, Proprietary said:

Oh thanks. Where can I find some relatively cheap, but new sas hard drives? Amazon/ebay/Newegg didn’t offer too many options...

I personally buy my drives from Disc Tech, but if you don't have a need for SAS, I wouldn't get the drives. They cost quite a bit more than SATA equals. They also typically run loud and hot.

 

I'd only get SAS if you legit plan to run these in a company setting with multi card setups.

[Electronics Wizardy]

46 minutes ago, Proprietary said:

Honestly... just to make my server more server-ish... don’t most servers use sas drives?

A lot of them use sata drives cause for most uses its not worth the extra money. And if you need the extra uptime just run a distributed file system.

 

You can go ebay hunting and get some cheap ones, but really there already pretty well used.