SATA III/SAS 6Gbps RAID Setup

[timbilt]

I am in the middle of purchasing the parts for a new computer I'm building. I am sure I will be going the GIGABYTE GA-Z77X-UD5H motherboard. I require a RAID setup to make sure that I don't lose my data because of a single hard drive failure. I wanted to use a RAID 5 or RAID 10 setup but ensure that the drives be able to function at 6Gbps each. I see that with the LSI RAID controllers, the SAS to SATA fanout cable causes the SATA drives to operate at the SATA II 3Gbps rate. Is there a controller that doesn't cause this to happen?

Also, most RAID controllers have 1 or 2 mini SAS connectors. How do I connect 4 SAS drives each mini SAS port?

I will be installing an SSD for the operating system and want to make sure that I have a solid RAID setup to store my data and VMs.

Thanks in advance.

 

[Dereck47]

I see that with the LSI RAID controllers, the SAS to SATA fanout cable causes the SATA drives to operate at the SATA II 3Gbps rate.

Are you sure you read the specs right? I would have thought that the fanout cables that LSI supplies with their RAID cards operate at 6Gb/s.
If not, here's a fanout cable you can buy that works at 6Gb/s:
http://www.datoptic.com/29-inch-internal-mini-sas-sff-8087-cable-1.html

 

[timbilt]

Here is the link to the LSI controller I was looking at.

http://www.newegg.com/Product/Product.aspx?Item=N82E16816118107

If you click on the embedded youtube video of the features and unboxing of the card and go to 1:50, he says that if you connect SATA III drives to it they will function at the SATA II rate of 3Gb/s. I don't see why they would do that...

 

[Dereck47]

LSI is just being cheap. If you pay 360.00 you would expect that they would include quality cables.

The fanout cable that I linked is compatible with your card and will connect 4 SATA or SAS drives.

 

[timbilt]

I thought that they were saying that all SATA drives are going to be demoted to 3Gb/s? I'm sorry to ask but are you sure it's just a cable issue and not just the way the card functions?

Thanks for your replies btw.

Also, how would I connect 4 SAS drives to it? Thanks.

 

[Dereck47]

It's just the cable. If you click on the "Details" tab on your Newegg link you will see "Transfer Rate Up To 6Gb/s)".

 

[timbilt]

How would I connect, say, 4 SAS drives instead of 4 SATA III drives?

 

[Dereck47]

You connect the SAS & SATA drives the same way: connect the single end of the cable to your RAID card's internal port and the other 4 ends to your 4 drives.

You'll have to do some additional research if you want to connect more than 4 drives.
The spec sheet says that your card can handle up to 128 drives, but I don't know what kind of cable or equipment you need to connect more than 4.

 

[timbilt]

What I mean is - there is 1 mini SAS connector on the controller and they profide a fanout cable to connect one end to that 1 mini SAS connector and the other ends to 4 SATA drives. Is there a fanout cable that you can use to have 4 SAS connectors to 4 SAS drives instead of 4 connectors to 4 SATA drives?

The reason I'm asking is that even though it says there is a 6Gb/s throughput, I see other people complaining of the 3Gb/s with SATA drives so I was just gonna buy some SAS drives to be sure I'll get 6Gb/s for each drive.

Thanks.

 

[Dereck47]

Yes, the cable I linked will connect 4 SAS drives. Each of the 4 connectors on the cable can speeds up to 6Gb/s.

SATA 3 (6Gb/s) speeds are from 301MB/s to 600MB/s.

Hard drives can be SATA 3 compatible, but not SATA 3 capable.
No hard drive can spin fast enough to saturate a SATA 2 (3Gb/s) port, let alone a 6Gb/s port.
So even if you buy a 15,000 rpm SAS drive you won't get SATA 3 speeds.