RAID-1 @ GSATA on GA-870A-UD3 Rev. 2.1

[CryGuy]

Hi,

first, I do know what a RAID is and the drawbacks and benefits of the different levels. (I'm writing software since I was 13, which is 26 years ago now). Though I'm not sure about the reason in this special case.

System:

• Mainboard: GA-870A-UD3 Rev. 2.1, latest BIOS
• WD RE4 1 TB @ AMD SATA (AHCI)
• RAID-1 @ GSATA:
  Seagate ST2000DM001 (2 TB) + Toshiba DT01ACA200 (2 TB). The Toshiba drive is made by Hitachi, Model no is HDS723020BLE640. Both drives are 1 TB/Platter with 4 KB sectors.
• CPU: Phenom II X4 965 (3,4 GHz)
• OS: Win7/SP1, latest drivers

Problem: Read Speed is limitted to ~110 MB/s:


The picture obviously shows a bottle neck which is not the max drive speed. That should be > 150 MB/s even though I haven't found any benchmarks about the Toshiba drive, which is still new on the market. As the CPU usage during the test is max 10% (-1% in the picture has no meaning) I don't know what's the limitting factor. I know the GSATA controller it's internally connected via PCIe x1, but that should still be sufficient (max 500 MB/s).

I've searched and read hours about the behavior with this specific board, but as nobody complains, it's probably me doing something wrong.

Could anybody please tell me where there is this bottleneck? Is it just the GSATA controller which can't do quicker?

Thanks for reading.

[autotech]

Ran into the same problem myself. Took a bit but i got it figured. I was using a seagate and a westren digital both same size. Slow speeds. did alot of research and what i read was use 2 of the same make and model figured it was worth a try so i did it. Performance improved it had something to do with the different chipsets. My speed improved with two of the same make and model but i was using raid 0.
Hope this helps.

[CryGuy]

Hi,

thx for answering. Well, as the RAID-1 performance was not satisfying and I didn't find a better reason than the one you've mentioned - which is probably the reason - I decided to revert the RAID and use only one HD for data and the remaining one for normal backups (via eSata). I intentionally decided for two different brands (but which are pretty close together regarding specs) because of the remaining risk of having the same fault within the same production batch. BTW, the single Seagate makes ~200 MB/s and the single Toshiba ~170 MB/s.

(As I had some HDs left over, I'm now using a RAID-0 @ GSATA (made of a Samsung F4 320 GB and a Seagate 7200.12 500 GB) for unimportant data, e.g. a temporary directory for video processing. There a RAID-0 makes sense. Up to 158 MB/s. Both drives individually are at ~140 MB/s, so the RAID-0 is also not convincing. Though, one advantage is that, at the end of the data area, it almost keeps that maximum speed whereas each single drive would go down to ~80 MB/s.)

So, topic closed (for my part).