Rich Mingin (PLUG) on 18 Mar 2017 16:55:14 -0700

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Re: [PLUG] SAS / Storage

Ok, so a few things.

The ports you're breaking out into 4 SATA ports are miniSAS, not simply SAS. A simple SAS port can handle one SATA drive. SAS is a superset of SATA, that's why it works at all.

Also, if you're not looking to do RAID, you want an HBA, not a RAID controller.

If you're looking for decent speeds, make sure to get a modern chipset. For example, my LSI 1068E has a 2.2TB per drive limit. The LSI 2068 in another machine handles 4TB or more just fine, plus the chipset to drive link is 6Gbps not 3Gbps. The PCIe link is generally not going to be a limiter.

On Sat, Mar 18, 2017 at 7:34 PM, Rich Freeman <> wrote:
Ok, I've managed to accumulate a fair number of drives over the years,
which always creates challenges when I need another motherboard.
Right now I have 8 SATA drives plus 1 eSATA to contend with (though I
suppose I could move my eSATA drive internally and use another
internal SATA for it).

>From what research I've been able to do the way most people cram more
drives into a system seems to be with SAS RAID cards, using SAS->SATA
breakout cables.  You can apparently get 4 SATA ports out of 1 SAS
port and with cards typically offering 2-4 SAS ports that gives you
for support for 8-16 drives.

My question is whether there is anything I should be concerned about,
or looking for in buying a SAS card.  Will putting 4-8 drives into one
PCIe slot result in some kind of IO bottleneck?  Are there any gotchas
when using SAS->SATA, or with SAS cards in general?  Should I be doing
it some other way that doesn't involve SAS RAID cards?  I'll confess
I'm also not an expert on PCIe in general either, so is there anything
I need to be mindful of there other than whether the card physically
fits in the slot?

I'm not really interested in any RAID capabilities on the card itself.
I just want it to expose a bunch of disks to the OS.

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