Need advise about RAID/SSD performence

[zou]

I'm logging images to RAID/SSD.  ~2400FPS.

Option 1: 1 RAID controller + 8 SSD

Option 2: 2 RAID controllers, each controls 4 SSD

Would option2 logging faster than option1?

I've 2 threads running parallel.  Each recording a camera.

Win7, 64bit, LabVIEW2011

256GB for each SSD

[BillMe]

Your question isn't really related to LabVIEW. You're better off going to sites that review H/W performance differences such as Toms Hardware or Overclockers.

[unclebump]

Might need something like this.

http://addonics.com/products/ad2ms6gpx8.php

Using SATAIII ssd drives and 6Gb rated ports?

Tell us more about the hardware and computer being used.

[PhillipBrooks]

Experience / suggestions:

On a much older setup with RAID, I found that Windows would cache large amounts of disk writes and then try to commit them all at once. This caused my acquistion to drop UDP packets because the OS was pegged at 100% writing large blocks of data in batches. I simply used the flush file primative every "n" writes to prevent the OS from buffering too much.

Your disk cluster size can have an effect on performance. If your images are a multiple of 4k in size, increasing the cluster size can improve write times by reducing the number of MFT updates.

Rotating disks become fragmented and performance will go down. Consider a good defrag utility and/or partition your volumes so you can have a dedicated acqustion area that can be copied to an archive volume and then reformat your acq volume. SSDs should not be an issue...

[crossrulz]

I also depends on your RAID format.  Are you using RAID 0?  RAID 5?  RAID 10?

[josborne]

Wow, I am impressed by your goals ... 2400 fps!

I had trouble getting my system to manage 240 fps.  But I only had a couple HDDs in RAID0.

To start, I think you need to calculate your criteria in MB/s ... e.g. are you writing high res images in color? ... then some HW gurus can help you out.

When you find a solution, please update this post

Also, you might want to look here:

https://www.ni.com/en-us/support/model.hdd-8265.html

http://www.ni.com/white-paper/5730/en 

[zou]

Wow.  Thanks for all the response.

A little more info about the project:

I have a RAID controller: 6 Gb/s per SAS port, 8 ports.  SSD drivers: 6 Gb/s, 256 GB each.

The host is a server running  Win7 64bit.  2 processors 1.8 GHz.  8 GB RAM.

Currently, it's working fine for 2 cameras, ROI = 480 x 640.  8bit, 10tap, grayscale.  Average FPS: ~2400

Acquired images are merged into a large one: 10 ~ 100 times of ROI before write to disk, to reduce the write function call.

Write to disk seems to be the bottleneck.  Tried flush everytime.  No noticeable difference.  Since the merged image is large enough.

The drive (one controller => one drive I suppose) is wipped clean everytime for next test.

Not sure about the RAID configure.  The configure software is not easy to use.

The reason I posted is that we are going to expand to 4 cameras.  That's 4 threads in parallel logging to disk.

[unclebump]

have you tested any benchmark software to see how the drives are working? Anandtech forums mention AS SSD benchmark.

[unclebump]

This is the fastest board that I can find.

http://www.newegg.com/Product/Product.aspx?Item=N82E16820227772

This thing has 5x the performance of a new Samsung 840 PRO SSD, but costs a fortune!!!

[unclebump]

might want to look at promise pegasus R4 or R6 SSD with thunderbolt connection.

http://www.promise.com/storage/raid_series.aspx?m=192&region=en-global&rsn1=40&rsn3=47

Darn it!! just noticed that they only work with a MAC OS X computer.