the last drive I added to my system required me to delve into SATA cards, so I insalled a Supermicro AOC-SASLP-MV8 card onto my system.  The drive was a WD 2TB EARS with a jumper across pins 7-8.  Ever since I have done this, my write performance has consistently gone to 9.5-10 MB/sec.  Now copying from my main linux desktop to my unRaid box has always been variable (anywhere from 5-40 MB/sec), but now I'm just always slow.  It's not a killer problem for me, but it is annoying.  parity checks seem to be reasonable (60-95 MB/sec).

 

What should I be looking at?  How do I check to make sure my drive is jumpered correctly (ie, could the juper be faulty), and is there anything to configure for the Supermicro card or is that just plug and go?

 

thanks for any help.

c+h

The SuperMicro card should be plug and play.  What breakout cables are you using?

 

Also, did you ever use the WD EARS drive BEFORE installing the jumper?  Some people have run into similar performance problems caused by that.

The SuperMicro card should be plug and play.  What breakout cables are you using?

SI/3Ware CBL-SFF8087OCF-05M SFF-8087 to Discrete Forward Breakout Cable

Also, did you ever use the WD EARS drive BEFORE installing the jumper?  Some people have run into similar performance problems caused by that.

Drive never touched a power cable until the jumper was installed.

Hmm, looks like the right cable.  Can you outline your whole system for me?  Specifically, what motherboard are you using?

Asus P5B deluxe.

7 various brand HD's on the motherboard

1 HD on the Supermicro card.

650W Corsair power supply, single 12V rail (can't think of the model # off hand, not at home).

Hmm, very odd.  You could try switching things around to see if there's a bad bit of hardware anywhere.  I would do this (in this order):

- Swap the plugs for the WD EARS hard drive and another known good one that is connected to the motherboard

- Swap the SATA cables

- Try the second SAS slot on the SuperMicro card. 

- Swap the PCIe x16 slot that the SuperMicro card is plugged into.

 

Also, are you using any backplanes or drive cages?  Or are all the hard drives hooked up directly to the card or motherboard?  If there is anything between the hard drives and the motherboard/supermicro card, eliminate it until you figure out what is going on.

I'm aware this is a very old thread but to date I'm experiencing the same problem. Normal read speeds - above 100MB/s - but disappointing write speeds - 25/40MB per second.

 

I can't move the controller to any other slot because the 4x is the only one I have and I'm not sure the cables are the problem at this point, otherwise why would the read speed be OK?

 

Anyone?

The OP was getting 10MB/s, that is slow, depending on the model disks you have and if you are writing to the first or last disk cylinders those can be normal speeds, writes to the protected array can be a little faster using the first half of fast disks, between 50 and 60Mb/s is the best I’ve seen so far, doubt that there is anything wrong with the SASLP.