Slow RAID 0 Performance

[conlan]

Please save the RAID 0 is evil speaches, I know the risks and don't store anything of value on the array, thank you

Specs:
Gigabyte GA EP45 UD3P
C2D E5200 @ 3.33 GHz
2 x 2 Gskill DDR 1066
2 x WD Raptors ADFD (the newest ones)
1 x 3Ware 8006 2LP controller (latest BIOS and drivers)
Win XP SP3

In HD Tune with 1 (one) Raptor on onboard controller I was getting burst speeds of 118.4 MB/sec.

With both Raptors on the 3Ware controller, I'm getting only 55 MB/sec. burst.

TIA for any help

 

[Rubycon]

Forget burst speed - it's useless!

What is the beginning, ending, average transfer, access time and CPU utilization look like?

 

[conlan]

Originally posted by: Rubycon
Forget burst speed - it's useless!

What is the beginning, ending, average transfer, access time and CPU utilization look like?

1 Raptor on onboard controller:

Transfer Rate:
Min. 35.0
Max. 79.8
Avg. 68.6

Access time: 7.9ms
Burst 118.4
CPU 1.7%

2 Raptors on 3Ware:

Transfer Rate:
Min. 36.5
Max. 92.6
Avg. 72.5

Access time: 7.8ms
Burst 55.5
CPU 5.9%

 

[TC91]

have you tried raid 0 on the onboard ich10r? I think it might be a bit faster.

 

[conlan]

Originally posted by: TC91
have you tried raid 0 on the onboard ich10r? I think it might be a bit faster.

Thought of that, and you may be right, but i'd rather stick with a Hardware controller. It's possible the 3Ware controller is showing it's age.

 

[conlan]

Halp?

 

[MerlinRML]

Originally posted by: conlan
1 Raptor on onboard controller:
Transfer Rate:
Min. 35.0
Max. 79.8
Avg. 68.6

2 Raptors on 3Ware:
Transfer Rate:
Min. 36.5
Max. 92.6
Avg. 72.5

Anytime I see 100MB/sec maximum, the first thing I think of in terms of bottleneck is always a PCI bus or Gigabit Ethernet limitation. Is the 3ware card plugged into a PCI slot by any chance?

 

[conlan]

Originally posted by: MerlinRML

Originally posted by: conlan
1 Raptor on onboard controller:
Transfer Rate:
Min. 35.0
Max. 79.8
Avg. 68.6

2 Raptors on 3Ware:
Transfer Rate:
Min. 36.5
Max. 92.6
Avg. 72.5

Anytime I see 100MB/sec maximum, the first thing I think of in terms of bottleneck is always a PCI bus or Gigabit Ethernet limitation. Is the 3ware card plugged into a PCI slot by any chance?

Yup, the 3Ware 8006 is PCI-X

 

[Rubycon]

Could be bus hogging/ sharing. Definitely should be higher than that!

 

[conlan]

I was afraid that might be the problem. Probably should upgrade to a newer PCI-E controller.

Anyone have experience with the Dell 5e and 5i server pulls?

 

[postmortemIA]

just do it on onboard RAID controller

it is right on southbridge

no matter ho much you pay, onboard will be still faster

 

[conlan]

No thanks, I'm aware of where the onboard RAID controller is, and as posted above, am only interested in using a good Hardware controller.

 

[pjkenned]

I used the Perc 5/i's for a while. $120 including the BBU and upgrading to the 512MB ECC DDR2. I no longer use either Perc primarily because I am out of PCIe slots, and because I've standardized on Adaptec controllers so I can manage all arrays on the network using one piece of software. I may use one of the Perc 5/i's in a linux server box that I'm making from spares though. The other one I'll either stick on ebay or send to the spare bin.

Great cards and 512MB cache is really great because it soaks up lots of I/O in normal desktop usage.

One negative is that the card in raid 5 tops out in the 250-300MB/s range for writes and 500-700MB/s range for writes. On the other hand, with only two drives, you won't hit those speeds for quite a while, and raid 0 doesn't have the parity calculations which appear to be limiting the throughput mentioned above.

For some raid 0/1/5/50 tests using the 1.5TB seagates I would say see the thread on XtremeSystems... but since that is still down, and who knows if it will come back I uploaded some Atto tests on my site: http://www.servethehome.com

 

[mooseracing]

Perc 5 is great as well as the Perc 6 for the price.

 

[bigi]

8006 is really a 2 generations step back. Likewise pci-x does not help either.
I use 9650 on pci-e x16 and get 270-300mb/s rates constantly in raid 5. I don't think you can be helped as all seems to be hardware limited.

 

[conlan]

Originally posted by: bigi
8006 is really a 2 generations step back. Likewise pci-x does not help either.
I use 9650 on pci-e x16 and get 270-300mb/s rates constantly in raid 5. I don't think you can be helped as all seems to be hardware limited.

I know I can't be helped

I was concerned about the RAID controller. I'm looking for a newer PCI-E replacement. :thumbsup: