Hi~

 

How would I use controller to have 24 sata port connecting harddisk?

I knew I can use INTEL RES2SV240 24-port SAS RAID Controller, but any else I need to buy together with this controller?

 

Or any other else for better choice?

RES2SV240 is a SAS expander, not a controller, it needs to be connected to a SAS HBA, e.g., LSI 9211/Dell H310/IBM 1015.

 

Note also that 4(single link) or 8(dual link) ports will be connected to the controller, leaving you with 20 + 4(on the controller) disks max for single link and 16 disks max for dual link.

Thanks Johnnie.

 

What situation we should use single and dual link? for better speed performance?

 

Any SAS HBA and expander you suggest for my case?

Single or dual link will only make a difference for operations that access all disks simultaneously, like parity check/sync and disk rebuilds, with a 8 port LSI based controller like those I mentioned above plus a RES2SV240 this is the max speed you can expect:

 

20 disks with single link = 110MB/s

16 disks with dual link = 185MB/s (275MB/s with a PCIe 3.0 HBA)

 

16 and 24 SAS controllers are very expensive, it's often cheaper to buy a 8 port controller + expander, depending on how many PCIe slots you have it can be even cheaper to buy multiple 8 port controllers, like the Dell H310/IBM M1015 on ebay.

Ok. So it affect each harddisk read/write speed (up to 275 MB).

 

But if I use dual link, should i purpose buy two SAS HBA, and one will be connected to the expander?

If you have 2 PPCe slots it's a good alternative, this is what I use on my 30 drive server:

 

1 x Dell H310 + RES2SV240 using Dual link - 16

1 x Dell H310 - 8

Onboard Sata - 6

Total            - 30

Thanks Johnnie. I understood finally the concept, but if I prefer to save PCI slot, I can still use one card + expendar (4 + 16 sata port). (as I will buy motherboard which only have 3 PCIe 3.0 x16, 3 PCIe 3.0 x1, and I will have 2 PCI 3.0 x 16 left for other purpose)

 

I am thinking it is balance between money and no. of PCI slot occupied. Most of standard harddisk has less than 100MB/s read/write, then I can't see the point why using double link to do so. Please correct me if any misunderstanding.

You can use a single controller with the expander and connect 24 disks (20 on the expander + 4 on the controller), array read/write performance will be normal, the same as if you used dual link, there will be a slight slowdown during parity check/sync and disk rebuilds, but the performance will still be very good, should do 100MB/s+.

Hi Johnnie~

If I would like to have extra sata port only, any choice of PCI to sata card (without raid function) to save the cost?

Asmedia 1601 based controller, like this one:

 

http://www.newegg.com/Product/Product.aspx?Item=N82E16816124045

 

Cheap and work great with unRAID.

Then would I have 24 sata if using this kinds of card while occupied one pcie (just like Dell H310 + RES2SV240)?

Don't really understand your question, you should be able to use as many of these cards as free pcie x1 slots you have, each one is good for 2 disks.

Any choice for (single?) card supporting 24 sata port if I don't need raid function at all?

 

To think about this, I can Dell H310 + RES2SV240 occupied only one PCIE slot, how about the card without raid function but still occupy only one PCIE slot?

I'm sure there are but don't know any unRAID compatible, these are, but only 16 ports:

 

http://www.newegg.com/Product/Product.aspx?Item=N82E16816118142&cm_re=SAS_9201-16i-_-16-118-142-_-Product

Understood, it is better choice for using Dell H310 + RES2SV240 to save pcie slot. Thanks.

I find the card require 8-lane, PCI Express 2.0, so would I install the dell raid card into PCI-E 3.0 x4 (in x8 slot)?

PCIe x4 slot 2.0 or 3.0 has just about enough bandwidth for the H310 with 8 HDDs, you won't notice any significant slow down.

If you have 2 PPCe slots it's a good alternative, this is what I use on my 30 drive server:

 

1 x Dell H310 + RES2SV240 using Dual link - 16

1 x Dell H310 - 8

Onboard Sata - 6

Total            - 30

 

johnnie, just curious.  What's the advantage to having it setup like that rather than just sticking another H310 in there, which would have been cheaper I would imagine that the RES2SV240?  I've also got a server and enough space for 30 drives, and currently have two H310s, was planning to buy another but am I missing something?

If you have 2 PPCe slots it's a good alternative, this is what I use on my 30 drive server:

 

1 x Dell H310 + RES2SV240 using Dual link - 16

1 x Dell H310 - 8

Onboard Sata - 6

Total            - 30

 

johnnie, just curious.  What's the advantage to having it setup like that rather than just sticking another H310 in there, which would have been cheaper I would imagine that the RES2SV240?  I've also got a server and enough space for 30 drives, and currently have two H310s, was planning to buy another but am I missing something?

For me it's about available PCIe slots, board on that server has only 3 x4 or better slots, I need the 3rd one for 10GbE, if you have them available it's cheaper and potentially faster to use 3 x H310.

Gotcha, makes sense.  Thanks man.

Hi johnnie. Do you encounter incompatible case on raid card for specific motherboard / chipset?

I've read of some incompatible boards with the dell h310, a little masking tape solves it, but it always worked for me, I use them on Asus, Asrock and Supermicro boards.