Parity check speed slowed down after adding SAS card

[CaptainSpalding]

I have this mobo: https://www.asus.com/Motherboards/AT5NM10TI/overview/

 

I had 4x Seagate 4TB DM drives on it connected with sata and got about 100MB/s for parity check.

 

Now I added a 8 port supermicro SAS card (in my sig) and now the speed is about 30-40MB/s.

 

What kind of connector should I need that I could get that 100MB/s? A pci-e 16x 2.0? Does 8x be enough?

 

My older board had 16x with 8x when both pci-e ports are in use. I also got low parity check speeds, but I think that was due to older 2TB drives.  Or am I wrong?

 

I was thinking about upgrading the mobo but what would you suggest?

 

EDIT: Would it help to have parity drive in a sata port?

 

 

[Squid]

http://lime-technology.com/forum/index.php?topic=29009.0

[CaptainSpalding]

Thanks, I have to look in to that.

 

But at first seems that seems like there's a lot of risks involved.

 

Shouldn't there be a more hardware oriented solution to this?

[cassiusdrow]

I'd recommend putting the parity drive on the blue ports as those are the sata controller built into the chipset.  Also, use the rest of the sata port on the motherboard first.  The motherboard PCIe slot is v1 x4 slot and the Supermicro AOC-SASLP-MV8 is a PCIe v1 x4 card, so a better PCIe slot should make no difference.

 

What drives are you using besides the Seagate 4TBs?  Older 2TBs would slow down the parity check but 30-40 MB/s is unusually slow.

 

There may be a newer firmware available for the Supermicro AOC-SASLP-MV8 that might affect it's performance.

[Warp3]

I was searching this forum for the very same issue.  I have a completely different motherboard (a Jetway board from one of Rajahal's older 15-drive builds), but I just bought this same SAS card and am noticing the same issue.  It almost seems like it is only read speed that is notably affected as the zeroing part of the pre-clear took a pretty normal amount of time, but read operations (like a parity check and the read tasks of the pre-clear process) are much slower than normal.  It's an x4 card which I have in an x16 slot (the only PCIe slot on this board) so that part should be fine.  I'm using a breakout cable into four of the five ports of a Norco SS-500 drive cage (with the other port plugged into the 6th SATA port on the MB).

 

I have a parity check running right now and reporting 26.44 MB/sec as the current speed and is slated to take 42 hours (which is way longer than normal, even with 4TB of parity).  Oddly enough, I thought the slot I used in the new SS-500 bay (which uses a different port layout than the older SS-500 I have) was the onboard one (as this MB has 6 onboard ports), but if it is using one of the SAS cards ports this issue would make more sense, thus my search.

 

UPDATE: While typing this, I just remembered a post mentioning changing some settings on this card when you install it.  I disabled INT 13, confirmed this card doesn't seem to have RAID mode enabled (it is in JBOD already), and in the process confirmed that the onboard SATA sees all 6 drives and there are no drives showing on the SAS card (so I was right about which port it was using).  I then restarted the parity check and after a few minutes to settle in the speed went right back to what it was earlier (just over 26 MB/sec).  I wonder if it is even the card at fault now since the drive isn't attached to it, but the timing is awfully coincidental.  Unless the Jetway isn't playing well using all 6 ports or something.

 

UPDATE2:  It appears my problem was unrelated to this thread after all.  I had two settings in the BIOS I needed to change (for the motherboard, not for the SAS card). First SATA was set to "Native IDE" mode instead of AHCI. Secondly, SATA IDE Combined mode was enabled. After correcting those two (then fixing the boot order since the PC decided it wanted to boot from the HDDs now, instead of the unRAID flash drive), I started a new parity check: Speed: 103.39 MB/sec / ETA: 645 minutes.  That is *much* better.