Feedback on the newer Samsung PM1643

[NKarnel]

Hello everyone,

We are considering using the new Samsung PM1643 SAS drives instead of the SM883 SATA we usually used for our Ceph cluster.
Has anyone got any experience with them, any comparisons or recommendations regarding performance etc?

PS. I know this question might be a little bit not suited to this thread, but since we're using Proxmox, I thought that it was better asking it here since your workloads are probably similar - Virtual machines running small databases etc.

 

[Dominic]

Hi!

Have you purchased the new drives already? If you have not seen it yet, you could check out our Ceph benchmark for some ideas.

 

[Alwin]

If I am not mistaken, then these drives are multi-link. So, you will need two SAS ports to get them really flying. And I suppose in turn this will mean, that the backplane and the controller will need to support multi-link as well.

 

[LnxBil]

If I am not mistaken, then these drives are multi-link. So, you will need two SAS ports to get them really flying. And I suppose in turn this will mean, that the backplane and the controller will need to support multi-link as well.

So the disks are primarily not designed for CEPH, but for a multi-headed SAN environment.

 

[Alwin]

So the disks are primarily not designed for CEPH, but for a multi-headed SAN environment.

Not necessarily, multi-port and dual-port sounds similar but there is quite some difference. Dual-port has two controller on the SSD and usually two separate connectors. And the controller card will be linked with its partner card. Multi-port has one connector that get 2 x 12 Gb/s to provide the bandwidth.

 

[LnxBil]

Not necessarily, multi-port and dual-port sound similar but there is quite some difference. Dual-port has two controller on the SSD and usually two separate connectors. And the controller card will be linked with its partner card. With multi-port has one connector that get 2 x 12 Gb/s to provide the bandwidth.

Oh, I wasn't aware of that. Thank you for the explanation.

 

[NKarnel]

Hello,

No I have not bought them yet as I'm still researching.
Regarding the characteristics of the drive, the official PDF states Interface SAS 12Gbps (link) , so I'm pretty sure it will work with our SAS2308 cards, no?

 

[NKarnel]

Sorry for bumping, but as I'm getting closer to decision time, anyone got any feedback on this?

 

[elmo]

Sorry for bumping, but as I'm getting closer to decision time, anyone got any feedback on this?

There's a lot of factors to take into account when architecting a computer system. One of the most important questions you should ask is - What the heck is it that we are trying to achieve?

You shouldn't base your decision upon my response, but I can tell you why I choose NOT to go with the PM1643. Albeit fast, the PM1643 only have 1 DWPD, seemingly geared towards read-intensive operations. I have a mixed-mode requirement and went with the SM883 for this reason as they provide 3 DWPD. Also, lower cost (eg. lower capacity) would also give me the opportunity to invest in more of them for the same price.