Miserable RAID 0 Performance

[Psymon007]

I wasn't sure whether to put the post here or in General Storage...

I'm a little stumped so here goes:
My home workstation is an Asus PP-DLW / Dual Xeon 2.8Ghz / 2GB RAM rig

I've put in an old HP Netraid 1Si card and 3x oldish Hard Drives that I had lying around in a RAID 0 Stripe.
(dont know how to post screen captures so.....)

Channel0
(0:0)A0-2-Online is a Fujitsu MAN3367MP / Scsi lvl2 / 34731MB / no errors
(2:0)A0-1-Online is a Seagate ST373405LW / Scsi lvl2 / 70006MB / no errors
(6:0)A0-0-Online is a Maxtor ATLAS10K5_73WLS / Scsi lvl3 / 70148MB / no errors
This is all reported in Netraid Assistant
I am getting averages of 18-22MB/s with these three striped / seek times of around 8ms and Burst of about 28MB/s[/img]

I had the Maxtor in alone before with the same controller with the same speeds. Somewhere, something is blocking my bandwidth. HDTach's graph is almost totally flat and level, no runoff at all.

The card is set on Ultra2 / Wide / Write-Thru etc
The card is in the only PCI slot available which is furtherest from the CPU's

So all the SCSI fundi's out there - impart your wisdom please, it will be most appreciated.

 

[Psymon007]

Hi again,
I realise this is hardly an optimal RAID 0 setup, however I personally believe it should be running at better speeds. Also believe that there is SOMEBODY out there that can shed some light on the problem. Please folks, take 2mins to write a response if you have any idea..

Cheers

 

[4745454b]

Your running three different speed drives in an AID0 array and complaining of the speed??? Just as you lost the other 35GBs from those 70GB drives, they also had to slow down to match the speed of the slowest drive, the Fujitsu 35GB. With that drive in the array, the other two drives need to slow down to match its performance. I would remove it and run just a two drive array. You'll gain harddrive space (70x2=140, 35x3=105) and if I'm right, speed.

 

[Psymon007]

474545b, I appreciate the reply
However if you check out this review http://www.tomshardware.com/2002/01/17/fujitsu_man3367mp_/page3.html the speed statistics of the "slowest drive" are almost double what I am getting with these 3 in the RAID stripe. Also I mentioned that I had the Maxtor (the fastest drive in the array) connected on its own initially - with the same speed results. Therefore I am led to believe that the throughput issue is not due to a non optimal drive setup alone. The controller theoretically should also be capable of a darnside more that 22mb/s. One last thing, I guess I cant remove the Fujitsu from the stripe even if I "officially" fail the drive? I have to destroy the stripe and reinstall or am I wrong?

 

[4745454b]

Thats odd, I'm sure your using something more powerful then a celery 500MHz to... I also didn't see where you said you had the maxtor connected by itself, if I saw that I wouldn't have posted what I did.

I'm inclined to believe that its a controller/driver issue. I'm not sure how to properly diagnose the problem. Look for updated drivers, and/or diagnostic programs for the controller. I've unfortunately only played with SCSI, so I'm not sure how much help I can be.

Does the controller share an IRQ? In the device manager, view devices by IRQ and see it putting it on its on IRQ helps any at all.

 

[Psymon007]

Yeah I'm using 2 x 2.8GhZ Xeon setup. The controller is running on its own IRQ (21) according to Device Manager. As for drivers, the one installed comes from XP and the only other ones that appear to be available are oooold ones from HP (for Windows2000). I can try one of those I guess, I just hope it doesnt pork the array The HP Netraid Assistant application reports no errors (but it doesnt look like the most comprehensive program)
Oh and you mentioned that you have only played with SCSI - this is purely SCSI
Anyways again, I do appreciate the reply's, its a tricky one I think - hopefully a solution will present itself in time

Cheers M8

 

[4745454b]

Are you sure the controller can do more then 22mb? (you did say in your first post that it was old...) Can you get a different cable to see if the one your using is bad?

 

[Psymon007]

Hi again,
Yes I have tried 3 different cables all with the same results. The Netraid 1Si is a Wide Ultra2 SCSI controller which should theoretically be able to transfer 80Mb/s according to info I've found on the net.

HP NetRAID 1Si
Device Type: Storage controller (RAID) - plug-in card
Interface Type: PCI
Compatibility: PC, Unix
Storage controller
Controller Interface Type: Ultra2 Wide SCSI
Data Transfer Rate: 80 MBps
Buffer Size: 16 MB
Supported Devices: Hard drive, tape drive
Channel Qty: 1
Max Storage Devices Qty: 12
RAID Level: RAID 0, RAID 1, RAID 3, RAID 5, RAID 10, RAID 30, RAID 50
Processor: Intel i960 33 MHz

 

[Psymon007]

I've tried every driver available on the Internet, with no improvements. I'm back on the Windows XP driver as it seems the best of the bunch. Performance on the HDTach Graph still sticks at 22Mb/s from beginning to end. (slight dips along it but it certainly wont go higher). There are a few jumpers on the Netraid 1Si - I wonder if they could be a setting limiting throughput. I've looked on the net but cant find any documentation on the jumper settings.
Either that or this PP-DLW Motherboard's only PCI slot can only do 22mb/s maximum
Ready to give up and go back to my 55mb/s ata 200gb drive...bummer

 

[rebok]

Try This:

Q: how is the scsi cable terminated? on drive or stand-alone terminator.
if terminator, rated for ultra2 or better?

Round-Robin problem solving:
Connect each of the drives (only one drive on scsi cable for each of 3 tests). note serial transfer rate and burst rate for each drive.

burst rate for any ultra2 drive/controller should be ~85-90% of the spec's 80MB/sec ... say 70MB/sec.

what are your individual drive MB/sec results at say 0% 50% and 100% capacity?

B