SAS Benefits over SATA when using HDDs

[Nubbins]

As per the title. Is there any benefit in using SAS drives over SATA.

There's the obvious bandwidth increase but as mechanical HDD can't saturate a 6Gbps link that's a moot point.

Just seems that while SATA drives are readily available and at fair prices, the SAS equivalents are harder to source.

[yaroslav (staff)]

Yes, you are right.
You can see more at https://www.seagate.com/files/www-conte ... 1-1503.pdf and https://www.intel.com/content/www/us/en ... ducts.html.

[Nubbins]

Not entirely sure which part i'm right about?

Is there any real-world performance benefit in using SAS over SATA. I know there are differences in the duplex (full vs half) and the dual port for dual controllers etc... But does that translate to any performance gain in the real world?

Thanks again

[yaroslav (staff)]

Yes, reliability and performance are strong points of SAS drives and it does translate in better stability and performance of the arrays.
Found some nice comparison here https://www.diffen.com/difference/SATA_ ... ached_SCSI.

If you need high performance, please consider SSD. You can build RAID 5 out of SSDs (we do not recommend that configuration for spindle drives) after all.

[Nubbins]

As i need a 50TB useable HA pair, SSD is unfortunately out of the question as is 10k/15k SAS.

Looking at the ultrastar DC HC510 which are available in either SATA or SAS - both are the same drive just a different interface/controller.

Sorry to push the point but I'm really just trying to understand fully - Given the identical mechanicals (@7200 rpm) of the drive, why would SAS be more performant and reliable than it's SATA counterpart?

As an analogy, I see the SAS interface on a 7200rpm drive like putting F1 tyres on a ford mondeo - technically they're better than budget tyres but they won't make it any faster as the limitations are elsewhere.

Of course if I could actually source the 22x 10tb SAS version then I would but only SATA are available at present. Just want to know how much I'm shooting myself in the foot by going SATA.

[yaroslav (staff)]

Hi, sorry for the delay...

technically they're better than budget tyres but they won't make it any faster as the limitations are elsewhere.

You are right, but storage, might be a bottleneck here. If you go with SAS, it might be a bit faster as SAS drives are bit faster by design.

Just want to know how much I'm shooting myself in the foot by going SATA.

It really depends on the production. For some use cases, you do not need a pumped-up storage array.

I would recommend learning demand. You already have the production running, right? Just run Live Optics and learn your storage, networking, CPU, and RAM demands. Doing that provides you with more info on what you actually need. To run such tests, just open a support ticket with us. We'll handle the rest.