SATA SAS PCI-e x1 controller

[lotnik]

So basically all recommended controllers don't go on PCI-e x1.
Only one I can find have marvell chips.

Is there any other good PCI-e x1 card? I'm searching 6+ hdd cards.

thx

 

[sretalla]

The bandwidth needed for multiple SATA HDDs will exceed a single PCIe lane, so I don't expect to find many cards with the combination you're searching for. (a quick check indeed shows up many Marvel-based 4-port cards, but nothing more)

Maybe the message here is that you need a new motherboard.

 

[jgreco]

If you're careful you may be able to chop a card down. Years ago I chopped down a BR10i to fit in the HP N40L. A Dremel and shopvac and careful motions.

 

[lotnik]

The bandwidth needed for multiple SATA HDDs will exceed a single PCIe lane, so I don't expect to find many cards with the combination you're searching for. (a quick check indeed shows up many Marvel-based 4-port cards, but nothing more)

Maybe the message here is that you need a new motherboard.

I don't need top speed it's home use: pci-e x1 is 250MB/s, on GLan I will have theoretically 125MB/s.
More sata ports means less pci-e cards ;)

If you're careful you may be able to chop a card down. Years ago I chopped down a BR10i to fit in the HP N40L. A Dremel and shopvac and careful motions. :)

It's some idea :D

 

[sretalla]

I don't need top speed it's home use: pci-e x1 is 250MB/s, on GLan I will have theoretically 125MB/s.

OK, but have you considered how this bandwidth is going to be handled?

If you're mirroring drives, every write is sent twice to the card (and then once each to the disks in the mirror).

Disk latency is a very important factor in performance and as the communication to the card is only at 4Gbits and the SATA disks are at 6Gbits, you will add latency for even a single disk,let alone more than 1. Latency matters even when the amount of data needing to pass is small and is going to be hampered by the slower data rate.

In the read direction, the disks will be able to send data at 1.5x the rate the card can offload it to the OS (just with a single disk)... remembering the latency story here, it's going to be problematic even for small data transfers. Maybe someone else in the forum with experience in the area of using controllers with under-provisioned bandwidth can comment on how things go here, but I can only guess that buffers will fill, then re-sends follow.

I'm just trying to prevent buyer's remorse for you, but if you're happy with low speed and can get around the Marvel reliability problem, good luck to you.

 

[jgreco]

Back in the '90's I managed server builds for a regional ISP. Trying to come up with a platform that supported various BSD's and Linuxes well was not horribly difficult but not a lot of fun. Standardizing on well-supported parts like the Adaptec 2940 SCSI controller was very useful and allowed for spares to be stocked easily.

I would occasionally get insistent requests for alternative hardware selections. Got an insistent demand one day for an Adaptec 29160 (160MBytes/sec). The request was withdrawn when I pointed out that the host only had a dual 100Mbps ethernet (12MBytes/sec) and software at the time generally couldn't even max that out.

Now the thing you need to be aware of is that ZFS will happily clog that x1 PCIe pipe when doing scrubs or rebuilds. This could potentially be a bit miserable, or maybe a lot miserable, but given that cheap Dell HBA's are $30 ea it might be an entertaining experiment. Or a terrible waste of money. As long as this doesn't bother you, go for it. And I'm interested in hearing your results.

 

[lotnik]

@ sretalla I have now 8x hdd, 6 working (only 6 ports). They are all in mirrors 3x(2x3TB). I can connect them one by board one by pci-e. My case can handle 12, and it will be more than enough for me. I use nas to store raw material, for editing I download them on ssd, before I use disc and USB adapter - so it's a big improvement for me :)

For today it will be waste of money to change MB to have pic-e x4 ;)

@ jgreco I will post my results at end.

 

[sretalla]

OK, hopefully it will work out. Best of luck.

 

[nmg20]

I'm interested in a similar approach - have an old J1900N board with a PCIe x1 and mini-PCIe ports only which I'd like to hook drives up to. I'd be really interested in hearing how you got on, @lotnik!