Thread: Pegasus3 R8 setup tips / expected performance

Reply to Thread
Page 1 of 2 12 LastLast
Results 1 to 10 of 16
  1. #1 Pegasus3 R8 setup tips / expected performance 
    Senior Member Robino_J's Avatar
    Join Date
    Mar 2012
    Posts
    521
    I should be getting my Pegasus3 R8 this week and reading reviews online I see mixed results. Some report fast read results 1000mbps+ and others around 650mbps.

    I'll be using the unit with my new iMac Pro 10Cores, 64GB, Vega64 - and will work with 6k and 5K R3Ds at low compression 2:1 to 5:1 and also 4K DPXs (51mb per frame).

    I'm not expecting realtime 24fps playback from the DPXs but enough speed to work comfortably with R3D at better than 1/4th.

    I never worked with a drive array like this before, any tips from Pegasus owners on how to get the best performance with my setup? (should I keep Raid 5, what strip size do you recommend etc.)

    Thanks !
    Reply With Quote  
     

  2. #2  
    You will find that R3D decode, not the drive, is your bottleneck. RR-X solves thst problem, but 10.13.2 update and 10.13.3 both break it. Expecting fix soon from RED.
    Michael Tiemann, Chapel Hill NC

    "Dream so big you can share!"
    Reply With Quote  
     

  3. #3  
    Speed of your Pegasus3 will depend a lot on which HDDs are installed and your RAID configuration. The 8-bay unit should be able to get you >1600MB/s read and write under most conditions. I run RAID-6 on my Pegasus units. It’s a tad more robust and does impact speed just a bit, but I’ve had better luck with it.

    The drive is not going to be a bottleneck for your R3Ds. In fact, you will be able to play the 4K DPX stream off of it just fine too as that’s about 1250MB/s and quite possibly write them to disk that fast as well.

    RR-X can speed things up a lot, but it can also be a hindrance. It does not support several processing features that have come along since its release and it’s already obsolete in the face of multiple GPUs and some of the larger dual Xeon configurations out there. The iMac Pro sits in a spot where the RR-X will probably still be useful for a lot of the decode processing/ playback in editing and such, but you should not feel that it’s necessary. I don’t know if you’ll be using a RR-X or not, that’s just my current thoughts on it, since Michael brought it up. And yes, seems there are some compatibility issues at the moment.

    Back to the RAID config. A 128KB stripe size might work well for you. It really does not matter all that much with the current hardware. In years past, we could see a noticeable speed boost for large file I/O by using a larger stripe size. With the current buffering on the drives and performance of the host controllers it seems to interleave and push the data about the same either way. Larger stripe sizes can, in theory, make indexing and access/ reads of some types of data a lot faster, but you also end up reading and caching larger chunks. I would advise against going to 256KB or larger unless you *only* store large files like DPX and R3D, etc... As you can see a detrimental effect of 256KB+ when you’re accessing thousands of config files, small PDFs and images.

    I’ve seen some reports of slow performance on some of these RAIDs. Of the ones I’ve helped assist with, it seems they’re all too often chaining too many TB devices together or intermixing TB generations on the device chain. Or they have other issues with their RAID config or even the RAID operating int a failed state where performance is cut way down. Generally speaking, these RAIDs are pretty fast. Or as fast as you’re going to get from a handful of 3.5” HDDs.
    - Jeff Kilgroe
    - Applied Visual Technologies, LLC | RojoMojo
    - Just me and my 8K Monstro VV kicking ass.
    Reply With Quote  
     

  4. #4  
    Senior Member Robino_J's Avatar
    Join Date
    Mar 2012
    Posts
    521
    Thanks Jeff! Really appreciate you explaining all this.

    I won’t be using a RRX, not sure what drives they put in there I ordered a built to order drive directly from Promise.

    I’m planning on using Raid 6 as well for more security - The drive is set for delivery tomorrow, I’ll report back here.
    Last edited by Robino_J; 02-01-2018 at 12:00 AM.
    Reply With Quote  
     

  5. #5  
    Senior Member
    Join Date
    Dec 2009
    Location
    Hollywood, USA
    Posts
    6,351
    I'm using 8 x WD Red 8TB drives (with a 256GB cache) in a RAID5, and I'm getting about 1100 MB/s read:



    This was about a 10% increase over the previous 3TB drives that were originally installed in this RAID (a G-Tech). I was actually expecting it to be slower since the drives were almost 3 times bigger, but the opposite happened... which is a good thing.
    marc wielage, csi • colorist/post consultant • daVinci Resolve Certified Trainer
    Reply With Quote  
     

  6. #6  
    Senior Member Robino_J's Avatar
    Join Date
    Mar 2012
    Posts
    521
    Quote Originally Posted by Marc Wielage View Post
    I'm using 8 x WD Red 8TB drives (with a 256GB cache) in a RAID5, and I'm getting about 1100 MB/s read:

    This was about a 10% increase over the previous 3TB drives that were originally installed in this RAID (a G-Tech). I was actually expecting it to be slower since the drives were almost 3 times bigger, but the opposite happened... which is a good thing.
    That's nice performance - Is your enclosure using Thunderbolt 3 or another interface?
    Reply With Quote  
     

  7. #7  
    FWIW, I get about 1300MB/s read and 1070MB/s write on one of my Pegasus2 (previous Thunderbolt 2 models) with 8 x HDDs inside. I would have to look, but I think it has Toshiba 3TB HDDs in them. I don’t recall if that one is set up as RAID6 or I left it as RAID5. My other Pegasus2 R8 is definitely set up as RAID6 and also has 3TB HDDs in it (would have to look ti see which ones, HGST I think). It runs noticeably slower, similar to Marc’s numbers. The drives have a lot to do with it. Also have an Areca 8-bay unit with 4TB WD Black RAID Edition drives inside and that unit screams. The TB2 interface is the bottleneck for reads.

    Have an iMac Pro coming in next week it seems and I plan to pick up a Pegusus3 or Areca TB3 RAID to go with it. I kinda like the QNAP unit with both TB3 and 10GE that has 8 x 2.5” bays. But it’s expensive as I can get one of the Promise or Areca units with 8 x 4TB HDDs for the same price as that QNAP with no drives.
    - Jeff Kilgroe
    - Applied Visual Technologies, LLC | RojoMojo
    - Just me and my 8K Monstro VV kicking ass.
    Reply With Quote  
     

  8. #8  
    Senior Member Robino_J's Avatar
    Join Date
    Mar 2012
    Posts
    521
    Ok got the unit and setup a Raid 6 logical drive.

    Running a Blackmagic disk speed test while the drives are synchronizing I get 1500mb/s write and 1100mb/s read

    I assume it's going to be a little faster when synchronization is completed, but if it stays like that I'm happy, never had that speed before that's pretty amazing.

    Synchronization is super slow I think it's going to take long time to finish the process.
    Reply With Quote  
     

  9. #9  
    Quote Originally Posted by Jeff Kilgroe View Post
    FWIW, I get about 1300MB/s read and 1070MB/s write on one of my Pegasus2 (previous Thunderbolt 2 models) with 8 x HDDs inside. I would have to look, but I think it has Toshiba 3TB HDDs in them. I don’t recall if that one is set up as RAID6 or I left it as RAID5. My other Pegasus2 R8 is definitely set up as RAID6 and also has 3TB HDDs in it (would have to look ti see which ones, HGST I think). It runs noticeably slower, similar to Marc’s numbers. The drives have a lot to do with it. Also have an Areca 8-bay unit with 4TB WD Black RAID Edition drives inside and that unit screams. The TB2 interface is the bottleneck for reads.

    Have an iMac Pro coming in next week it seems and I plan to pick up a Pegusus3 or Areca TB3 RAID to go with it. I kinda like the QNAP unit with both TB3 and 10GE that has 8 x 2.5” bays. But it’s expensive as I can get one of the Promise or Areca units with 8 x 4TB HDDs for the same price as that QNAP with no drives.
    My Pegasus2 R6 in RAID 5 gets about 800 MB/s write and 815 MB/s read. Is that what you would expect for the R6?
    Reply With Quote  
     

  10. #10  
    Senior Member Robino_J's Avatar
    Join Date
    Mar 2012
    Posts
    521
    Ok after sync (had to do it twice because I changed my mind on the logical drives organization) I get 1557mb/s write and around 1200mb/s read

    Happy with that but wondering why Read is that much slower.

    Reply With Quote  
     

Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts