My current configuration is a RAID-0 with three conventional 2TB hard drives. I want to upgrade to three 1TB SSD EVO disks, also in a RAID-0 configuration.

Using SiSoftware Sandra, I found out that my T7500 Dell Precision uses SATA II (3Gb/s) in its preinstalled Dell 6 port SATA AHCI Controller, combined with a Dell SAS 6/iR Integrated Workstations RAID Controller (internally it's an LSI Logic SAS 3000 series).

I have trouble understanding the requirements for the RAID controller part that I need to upgrade. According to this report, which uses a RAID-0 with two 500GB EVO disks, I need to be able to throughput more than 1000 MB/s, or approx. 8 Gb/s, for sequential I/O.

My gut feeling says that the SATA limitation is the limit between RAID and disk, not the limit between mainboard and RAID. But my RAID supports SATA II, EVO supports SATA III. Should I upgrade my RAID controller? And if so, what properties should I query for?

Update: I have to admit (update after reading the first answer) that I am not certain whether the SAS controller is on board and whether I should look for a RAID controller with an internal SAS controller, or whether that would conflict.

closed as off-topic by JamesRyan, Rob Moir, Zoredache, Ward, EEAA Mar 25 '14 at 0:39

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  • I think question is more appropriate for SuperUser, but I think that requests for recommendations of hardware are generally frowned upon. – zymhan Mar 24 '14 at 16:03
  • @WildVelociraptor: I did't mean to ask for a specific model or brand. Instead, I am trying to find out what I should query for when searching for items to purchase. Perhaps I should try to rephrase my question. And indeed, I wasn't sure it belonged here or on superuser, so feel free to move it if it is OT. – Abel Mar 24 '14 at 18:06

A good hardware controller shouldn't have a bottleneck between the controller and disks. You will certainly be bottlenecked by your SATA II onboard controller if you connect a SATA III SSD to it.

You can't upgrade the onboard controller, assuming by onboard you mean that it's built in to the motherboard. If that's the case, then you'll need to buy a PCI express RAID card with SATA III ports. As for which particular model or brand to buy, that's up to you. Check the reviews, and make sure your particular drive doesn't have compatibility issues.

  • 1
    I found a few controllers, thanks to your answer. Indeed, the SAS is onboard. – Abel Mar 24 '14 at 18:05

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