SATA Controllers: Best bang for the buck ?

[Daniel-san]

Hi Guys
I'm Building a new FreeNas box; and I need information on sata controllers.

I will most likely be building this on a desktop motherboard.
I currently have 8x 2GB Harddrive in my Windows HomeServer that I'll be reusing.

from my research on here, I'll be needing 16GB of Ram for my 16TB config; with that being said, I need a new mobo, cpu and Ram. (haven't bought anything yet)

searching for motherboards (new and used), I'm not finding many with 8 sata ports. and if I do; they're not all 6gb/s, most will be 4x3gb/s + 2x6gb/s

so my questions are:

1) do I need 6gb/s transfer rate or will 3gb/s suffice ?
2) if I can't find a mobo with 8 ports, what PCI-E Raid controller card is recommended for a home setup ?

my goal here, is best bang for the buck, I'll be buying a new board and CPU along with 16Gb of Ram. I want to buy the right controller card to match my new gear (without breaking the bank)

can someone help me out ?

if I can get away with it, I'd prefer not purchasing a controller card, but with 8 drives.. it looks like I have no choice.

Thanks!

 

[Hexland]

IBM M1015 SAS controllers can be got for $50 on ebay... I'm using one with no problems (and it proved to be about 30% faster than my integrated main board controller)

 

[survive]

Hi Daniel-san,

I second the M1015 suggestion. Very nice controller....for best results you will want to flash it with what LSI calls the "IT" firmware, which dumbs the card down (gets rid of all the RAID functions) to where it's a very fast HBA, nothing more.

You can get cables (you want SFF-8087 to SATA) for ~$10 from monoprice.com and as a bonus you can clean up the rats nest of SATA cables. While you are there get a pair of Molex to 4 SATA power cables for an extra clean install.

Also, here's my go-to list for controllers: http://blog.zorinaq.com/?e=10

-Will

 

[alawadhi]

Hexland...

Are you using the optional RAID5 on your IBM 1015? Or just RAID0/1?
I am thinking of using this card along with AMD Phenom II 4x, 8 or 16GB RAM, Infiniband card, 2x or 4x Gbps network.
Infiniband will be used for direct connectivity to an ESXi host, normal network is for the rest.

Thanks...

 

[Daniel-san]

Thanks Guys! really good info here.


8 drives on 1 card.. on the 8X PCI-E bus.

would I benefit from getting 2 of these cards ? or would that be a waste of money ?

 

[survive]

Hi Daniel-san,

I don't think 2 controllers would get you anything if you split a 8 drive raidz\z2 across them. I would imagine you would gain some increment of reliability if you made an 8 drive pool out of 4 mirrors with 4 drives (1 per mirror) on one controller, & 4 drives on the other.

Keep in mind you don't want to use any of the hardware RAID features of this card.....part of the reason it's so cheap is no on-board cache or BBU.

-Will

 

[Daniel-san]

I'd set them JBOD on both controllers, and have 4 drives on each M1015 card.

I was just thinking that because 8 drives on the same PCI-E slot seems like a bottleneck to me. and if 50$ can avoid a bottle neck.. then why not right ?

 

[survive]

Hi Daniel-san,

I don't think 8 mechanical drives really have any chance of overwhelming an 8x PCI-e slot.

Even if they do, where's all the data going to go....you would need a bunch of clients connected through a bunch of NICs to come cloase.

-Will

 

[Hexland]

I'm just running the M1015 in IT mode (JBOD) with 6 x 2Tb drives attached.

Unfortunately, I'm using an HP Microserver N40L, so I only have a single x16 slot (the x1 slot has an Intel Gb NIC installed)...

It's fast as hell though, so I don't think you'll max it out any time soon.

 

[paleoN]

I'd set them JBOD on both controllers, and have 4 drives on each M1015 card.

I'd flash the controller to IT mode like survive suggested. Some controllers still stick meta data on the drives or will drop drives via TLER issues, etc in JBOD mode . Maybe the M1015 is well behaved though?

I was just thinking that because 8 drives on the same PCI-E slot seems like a bottleneck to me. and if 50$ can avoid a bottle neck.. then why not right ?

No bottle neck with spinning drives. From the controller blog above - [SAS] LSI SAS2008, 6Gbps, PCIe (gen2) x8 [300-350MB/s/port].

For reference, the maximum practical throughputs per port I assumed have been computed with these formulas:

* For PCIe gen2: 300-350MB/s (60-70% of 500MB/s) * pcie-link-width / number-of-ports

As an aside survive has convinced me to get the M1015 over the BR10i. It's a little more money, but easily worth it.