PERC 5i Slow

B

Bob21

Limp Gawd
Joined
Mar 11, 2006
Messages
167
I have had this card for quite some time and it went into a FreeBSD machine so I never really tested the speed until now. I ran a diskinfo test in FreeBSD and it maxed out at around 125MB/s with 8 2TB 5k3000's in RAID 5.

I was rather disappointed so I started doing some more testing. Here is the config...

  • Opteron 154
  • DFI NF4
  • DELL PERC 5i
  • BBU Installed
  • 512MB cache installed
  • Read ahead & Write Back enabled

Here is what I have tried so far and the results:

  • Moved card to different PCI-E slot
  • Covered the SMB pins
  • Switched out the cache
  • Moved card to a different motherboard
  • Used windows to test
  • Different cables
  • Lastly I took 4 of the disks and created a RAID 0 array


Results of RAID0 array:

perc5-1.png

perc5-2.png





I hope I am just overlooking something... you can tell by the tests the drives are not the issue...
 
1. Is the PERC 5i cooled properly?

2. Turn on adaptive read ahead. It is better than regular read ahead.

3. Have you tried forcing write back to be enabled? Option in the firmware that says to turn it on even if a BBU is not present.

4. Just to confirm.. are you using a single sided 512MB DDR2 400 or higher stick of Registered ECC in a 1rx8 or 1rx16 configuration?

5. What firmware are you running on the PERC 5i?
 
cyclone3d said:
1. Is the PERC 5i cooled properly?

2. Turn on adaptive read ahead. It is better than regular read ahead.

3. Have you tried forcing write back to be enabled? Option in the firmware that says to turn it on even if a BBU is not present.

4. Just to confirm.. are you using a single sided 512MB DDR2 400 or higher stick of Registered ECC in a 1rx8 or 1rx16 configuration?

5. What firmware are you running on the PERC 5i?
Click to expand...


1. The card has active cooling and barely gets warm.

2. I have tried adaptive read ahead.

3. The RAID 0 array has force WB enabled

4. 512MB single sided PC2 3200R

5. I'll have to check

BTW I have the mega raid manager installed. It see's the bbu and it is charged. It also see's the cache

The thing the gets me is the "cap" at 100 MB/s?
 
What options are you using w/ HTune Pro?
Rate, etc
 
I believe you need to change it to 1MB/2MB to get accurate results due to the array size.
I'll reply to this thread once I get home.
 
Looks like your Block size is set below your Stripe size. Do like DSee said above, set the block size in HDTune to 512k or larger. You're basically benchmarking a sigle disk in your array right now.
 
Are you sure the PCIe port you used on the motherboard is x4 electrical (or greater)?

Is the battery connected and in good shape? If not it will default to write-back.

It was a slow card when it was new.
 
I'll echo evil4blue above. What is your stripe size on the array when you set it up?
 
zEp said:
Are you sure the PCIe port you used on the motherboard is x4 electrical (or greater)?

Is the battery connected and in good shape? If not it will default to write-back.

It was a slow card when it was new.
Click to expand...

The PCIe slots are good to go, although 1 lane can still transfer faster than 100MB/s

Everything I have seen tells me the battery is good to go

The PERC 5i should be able to sustain 500 MB/s read which is plenty fast
 
Just to stir the pot with the whole block size thing. Here is a bench of 2 Intel X-25E's on an Intel ICH10R write back DISABLED. 128KB stripe size, same HDTune.

x25e.png
 
Change block size @ HTune options to 1M/2M, re-run test and post results.

See screenshot below (4x 2TB raid5 - perc5i):

perc5.jpg


I'm sure this array can be tweaked/adjusted..
 
Last edited:
Thanks for the advice.

Here is where I am at and I need some more advice. The card is not the issue so I just want to make sure the real world performance will match the benchmark. I am no expert when it comes to file systems, but are there any changes I need to make in order to see better transfers? Does this mean only a file system with a large block size such as 1M will take advantage of the speed? OR Do I need a raid card that can handle a 1M stripe size? Or is there a firmware that allows this on the PERC?

Here are all 8 drives in RAID 5 with a test block size of 1M.

08-June-2011_18-09.png



Here is my FreeBSD test:

diskinfo.png
 
Last edited:
I decided to do some more testing and here it what I came up with.

My PERC had a max stripe size of 128KB. I found that the LSI version of this card has a newer firmware that supports up to a 1M stripe size so I decided to give it a go. Flashed the PERC, setup a raid 5 array with a 512KB stripe and re-ran the test inside of FreeBSD.

Here are the results:

I also did an Rsync restore which I have done before and noticed a huge improvement in the transfer speed. I am happy now..

PERC%205i%20512kb.png
 
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