Author Topic: Typical Parity computational speed??  (Read 3763 times)

Offline BigXor

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Typical Parity computational speed??
« on: August 20, 2012, 09:09:24 pm »
I have a quad core cpu running at 4GHz

I created a test pool of 2 DRU's and 1 PPU - Cruise Control

I put about 150GB's data on the drives before creating the pool.

The parity calculations are running at 7.63 MB/s

Seems like that is really slow. CPU is 3%

15 minutes =5%

Can I turn up the speed? 
« Last Edit: August 21, 2012, 02:15:14 am by BigXor »

Offline frason

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Re: Typical Parity computational speed??
« Reply #1 on: August 21, 2012, 04:29:02 am »
Depends on your drives (or anything interfering).
My parity calculation runs @ 95-100MB/s with PPU on a Samsung HD204UI.

7 DRUs (with about 8TB of data) and 1 PPU as above.

Check CPU usage, test drivespeed outside of FlexRAID.

Offline BigXor

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Re: Typical Parity computational speed??
« Reply #2 on: August 22, 2012, 06:06:20 pm »
My drives are Hitachi 5k3000 connected to a LSI 9211-8i controller.

The throughput tested at 120MB/s all drives

I'm using the free trial if that makes any difference.

I reinstalled FlexRAID and use all parameters at default and still the parity computes at 7.6MB/s

Any assistance would be appreciated.

[Update]  I connected the drives to an Adaptec controller and no change in speed.
« Last Edit: August 22, 2012, 06:45:37 pm by BigXor »

Offline themaddhatter

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Re: Typical Parity computational speed??
« Reply #3 on: August 22, 2012, 08:40:48 pm »
I just rebuilt my raid array, and I was running ~ 15 MB/s

It took ~ 34 hours to build a 29.1 MB usable array with 2 parity drives (~70 min/TB).

This is with an LSI 3801E HBA, 13 Samsung 2TB drives, & 4 Hitachi 3 TB enterprise drives.

Last time I built the array was using the onboard ACHI controller & the 13 Samsung drives, and it took ~ 70-75 minutes per TB (about the same).  Been that way since I was in the betas

Don't know what frason is doing to get that parity calculation rate, but I pretty consistently am getting the same on rebuild: 75 minutes per TB.

Everything I have read is that arrays take time, but I would love to know how to build a 29 TB array at frason's rate

Offline frason

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Re: Typical Parity computational speed??
« Reply #4 on: August 23, 2012, 02:46:14 am »
I haven't done anything specific, running on standard hardware, MSI P67A-GD55 on board SATA with Samsung HD204UI-drives.

Running Windows 7 Ultimate x64 with OS on a Intel 330 SSD.
« Last Edit: August 23, 2012, 02:48:17 am by frason »

Offline Brahim

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Re: Typical Parity computational speed??
« Reply #5 on: August 23, 2012, 02:56:47 am »

Offline BigXor

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Re: Typical Parity computational speed??
« Reply #6 on: August 25, 2012, 07:24:27 am »
I have processes set to = 3

and

I/O Buffer Size to = 128KB

Getting 99MB/s and pretty much maxes out the 4 cores.  ;D
« Last Edit: August 25, 2012, 03:43:22 pm by BigXor »

Offline BigXor

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Re: Typical Parity computational speed??
« Reply #7 on: August 25, 2012, 03:41:31 pm »
Just finished parity computations on:

DRU's = 6 Hitachi 5K3000 2TB
PPU's = 2 Hitachi 5K3000 2TB
Data  = 4.04 TB

Name: Parity Computation Process
Start Date: Sat Aug 25 09:11:27 GMT-400 2012
End Date: Sat Aug 25 11:07:37 GMT-400 2012
Duration: 01:56:10
Throughput: 98.76 MB/s


Looks like about 2TB hour.
« Last Edit: August 25, 2012, 03:45:16 pm by BigXor »

Offline Brahim

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Re: Typical Parity computational speed??
« Reply #8 on: August 26, 2012, 09:49:09 am »
So, the speed picked up afterward.
You will see a slower throughput while FlexRAID is processing smaller files and a greater one while it is processing larger files.