SATA port expanders

[Hardcore Games]

I was wondering if anyone besides me uses SATA port expanders. These can be run from one SATA port and fan out into 5 SATA drives. They can also be cascaded to 15 disks.

This is now a low cost motherboard can handle 45-60 hard disks in a rack mounted server.
The SATA III expanders I have cost < $20 and backblaze uses models that are slightly more expensive.

 

[cornemuse]

I have some that plug into the PCI express slots, , , , work OK

 

[FreedomEclipse]

Hmmmmmm.... but your bandwidth is being split 5 ways.

 

[eidairaman1]

Best off to get a dedicated pcie/pci raid card.

 

[natr0n]

Interesting I have never come across or even knew this exists.

I got ideas now.

Thanks.

 

[eidairaman1]

Interesting I have never come across or even knew this exists.

I got ideas now.

Thanks.

They lower bandwidth

 

[DeathtoGnomes]

They lower bandwidth

bring on the IDE speed nightmares....

 

[natr0n]

They lower bandwidth

I know. I was thinking of a scenario with an old mobo with like 2 sata only. This could be maybe used for added storage. Then again you could just get a cheap sata pci card or something.

It's nice to know its there if you need it is what I mean.

 

[rtwjunkie]

I was wondering if anyone besides me uses SATA port expanders. These can be run from one SATA port and fan out into 5 SATA drives. They can also be cascaded to 15 disks.

This is now a low cost motherboard can handle 45-60 hard disks in a rack mounted server.
The SATA III expanders I have cost < $20 and backblaze uses models that are slightly more expensive.

I don’t use them. I just use PCI and PCIe add-in SATA cards in my server. But thanks for the info, I didn’t know these existed. It may be worthwhile looking into this in the future in certain situations.

 

[thesmokingman]

Hmmmmmm.... but your bandwidth is being split 5 ways.

Technicalities!@!!

 

[TheLostSwede]

I have tested them in the past and they seem to work just fine, but as pointed out, there's a speed drop off compared to modern SATA controllers. However, it might not be as much as people expect. It also varies a bit between different port multipliers.
Wish the review I wrote was still around, but I think it's long gone, which is a downside with the internet...

 

[R-T-B]

Best off to get a dedicated pcie/pci raid card.

On embedded boards like OP was citing as a use case that may not be an option.

 

[newtekie1]

I've used them before, but in a slightly different format. I used 5-port external expanders connected to a single eSATA port.

Yeah, all 5 drives have to share the bandwidth of a single SATA port, but for the most part that isn't an issue. Remember, these types of setup are used for bulk storage, stuff that doesn't need that fast of storage. Plus, a SATA port gives 600MB/s of bandwidth. That'd be ~120MB/s per drive if you access all the drives all at once. A hard drive these reads/writes at like 160-200MB/s. So, yeah, you're loosing a little performance per drive, again only if you are accessing all the drives at the same time. But the reality is you have enough bandwidth to access at least 3 drives at the same time without any speed penalty.

 

[Hardcore Games]

https://hardcoregames.video.blog/2016/03/03/sata-port-multipliers/

I have a post on the topic and I have updated it a few times and most likely it will be edited more down the road

 

[eidairaman1]

I know. I was thinking of a scenario with an old mobo with like 2 sata only. This could be maybe used for added storage. Then again you could just get a cheap sata pci card or something.

It's nice to know its there if you need it is what I mean.

Just buy a pci/e expander card

 

[Grog6]

I use those for storage arrays.

Some of them will do software raid 5; I've lost disks, but you replace the bad disk, it rebuilds, and you're good to go.
A 10TB array can take 24+hours to rebuild if it's full, so you need to shut them down properly.
Ejecting them like a USB drive works.

I have yet to lose data, and I've been running them since about 2004 or so.

The first one I built is out of 233GB Maxtor drives, and is still running; the other two are 2TB WD and Seagate drives.

I'd recommend using the same type of drive, if you want to use raid.
With 5 drives and raid5, you lose the capacity of one for parity.
You can lose any one drive with Raid5, so you know when you need to buy a new drive.

No Intel sata ports support them; most other ones will.

I have a 4 port Silicon Image card that will handle 4 of them, but 2 10TB(8TB capacity) raid arrays is a lot of blurays, lol.
They don't have a problem playing video from the array.

They aren't blindingly fast, if that's your aim look into a SAS card and drives.

 

[Hardcore Games]

Intel seems to not like port multipliers and I have inquired about the issue.

Low cost Silicon Image cards can be used when a vast number of disks is desired.
15 port fanout is a lot of storage

the lower cost is the main thrust of my post

 

[newtekie1]

They aren't blindingly fast, if that's your aim look into a SAS card and drives.

That's what I'm currently using actually. Well, a SAS card and 12-port SAS expanders, but SATA drives.

 

[DeathtoGnomes]

Intel seems to not like port multipliers and I have inquired about the issue.

Low cost Silicon Image cards can be used when a vast number of disks is desired.
15 port fanout is a lot of storage

the lower cost is the main thrust of my post

you should ask @notb, he seems like the Intel expert here.

 

[Hardcore Games]

Testing the port multiplier from my MSI X570-A PRO motherboard, not detected. Instal a Marvell card and poof it works. So Silicon Image and Marvell support the port multiplier but Intel and AMD BIOS support is nonexistent.

so AMD and Intel are both deemed to be arrogant to not allow users to have low cost port multipliers.

16-port controllers are not exactly low cost.

 

[Grog6]

Intel has never supported Port Multipliers, iirc.

I first learned about them with a mobo with an SI chip, and I just happened to have a bunch of 233GB disks laying around.

They're great for storing stuff you don't want to lose, but don't need high speed transfer.

They would suck for video editing.

 

[newtekie1]

but don't need high speed transfer.

They would suck for video editing.

This just doesn't make any sense. My port multipliers give significantly faster speeds than a single hard drive would.

 

[Grog6]

The multiple drives are sharing a single port to communicate with the computer; I really don't think they're going to be faster than the connection.

You get the advantage of queing, but 2 drives on 2 ports is still going to be 2x faster.

The ones I have running raid 5 max out about 70MB/s. The raw drives are much faster.

 

[newtekie1]

The multiple drives are sharing a single port to communicate with the computer; I really don't think they're going to be faster than the connection.

You get the advantage of queing, but 2 drives on 2 ports is still going to be 2x faster.

Except hard drives don't max out a SATA port. No, 2 drives on 2 ports is not going to be 2x faster than 2 drives on a single port with a port multiplier. Yes, if you talk about SSDs, you are correct. But people aren't, or shouldn't be, using these for SSDs. We are talking about massive storage space here, and we are talking hard drives, and hard drives don't even come close to maxing out a single SATA port. In fact, two drives don't even max out a single SATA port. In fact, if you take the fastest drives out today, ones with read speeds in the 200MB/s range, it would take 3 HDDs to max out a SATA port. Yes, the drives are sharing a single port, but it is a port that has way more bandwidth than any single HDD can use.

The ones I have running raid 5 max out about 70MB/s. The raw drives are much faster.

That's because you're running RAID-5, not because of the port multiplier. And you'd probably get the same speed if each drive was connected to it's own port. RAID-5 speeds are largely dependent on how fast the RAID calculations can be done by the controller.

 

[Grog6]

Agreed, and I only use these PMs for Raid 5, for redundant large storage arrays.

For speed, I use 12k SAS drives in Raid 0, or 10k SCSI drives in Raid 0.

The PM's that I have are all over 10 years old, thinking about it; I'd bet the one I mentioned above is SATA I.

They work very well for what I use them for, which is redundant storage, with relatively low power.

I could use raid 5 scsi, with hardware raid, but these drive cabinets sound like a 747 taking off, and use a ton of power; I only use them for video editing or running a game server.

I don't use a lot of SSD drives, because when they fail, they're instantly dead, and they can die in storage; they're capacitors, and need to be rewritten fairly often.
I use them in laptops, that get backed up regularly; they seem to die within ~6 years.
I do like them booting windows in 10 seconds.