FORUMS: list search recent posts

should my NAS be dropping frames when capturing PAL footage?

COW Forums : NAS - Network Attached Storage

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Chris Craig
should my NAS be dropping frames when capturing PAL footage?
on Apr 29, 2016 at 11:58:36 pm

Hi everyone.

Please forgive my inexperienced question but im after some advice setting up my network.

I have 3 modern mac computers (iMac i7, two Mac Pros (late 2014) that i use for capturing VHS/Video camera footage for my clients. In the past each machine has been capturing to internal drives or external usb3 drives, but this has created an extreme amount of confusion or lots of work. So i have bought a synology 1515+ and based on the specs which should be able to eat this kind of thing for breakfast. The idea is to capture simultaneously to this drive.

However, i am finding that even capturing with a single machine to this drive, it drops frames and makes the capture un-usable. ( i have run the same tape to an internal drive without any dropped frames using the same capturing methods)

My setup up is as follows.

* Gigabit TimeCapsule to TP-Link 8 port gigabit switch.
* Each machine is connected to the switch with cat6.
* The synology 1515+ is connected to the switch with dual e6 cables.
* The synology has recommended 5x2tb red drives.

I do not have other software running on my machines when capturing. I almost always restart my machines after each long capture.

Can anyone suggest something that i am doing wrong or to look further into that are causing these dropped frames because i do not believe this should be happening with such a small data rate transfer.

Thanks very much


Return to posts index

Chris Craig
Re: should my NAS be dropping frames when capturing PAL footage?
on Apr 30, 2016 at 12:04:23 am

Sorry, i should have also mentioned that i do have a macmini server, but i don't use it for anything other than playing videos or music to the apple tvs in the house. Just in case this would help with my setup.
Thanks


Return to posts index

Bob Zelin
Re: should my NAS be dropping frames when capturing PAL footage?
on Apr 30, 2016 at 7:13:02 pm

While I am no expert in the sinology product line, it appears that you are doing many things wrong, including purchasing the wrong unit. The 1515+ is a 5 bay (not enough drives for 3 users reliably). It is a 1G box, and you say you are connected to a switch - this means that you are sharing all 3 computers over a 1G port - big mistake. You would be better off plugging directly into the 4 1G ports on this box, and assigning separate subnets. The 1515+ only has 4G of RAM, you should have at least 16. There is no option for a 10G port to feed a 10G switch.

Again, I am no expert in the product line from sinology, and I recommend other brands, but at first guess from 2 minutes of research, had you purchased the Synoloyg DS2015xs, you would have an 8 drive system with 10G ports that could go to a 10G switch, or at least a 10G uplink switch, to improve your bandwidth and performance.

So what do you do now ? I don't know - you bought the wrong box.
Try getting rid of your switch and plug directly into the 1G ports (assign static IP addresses), and see if that helps. But with only 5 drives and 4G of RAM, I don't know what will happen. This is not a word processing application - this is pro video, which uses tons of bandwidth.

The DS1515+ is $709. I don't know how you can have a working shared storage system for this price.

Bob Zelin

Bob Zelin
Rescue 1, Inc.
bobzelin@icloud.com


Return to posts index


Chris Craig
Re: should my NAS be dropping frames when capturing PAL footage?
on Apr 30, 2016 at 11:31:19 pm

Hi Bob

Thanks very much for your reply.

I do not know much about networking and have obviously fallen for a well-rounded marketing campaign from Synology (also budget requirements). I assumed for my needs of capturing DV footage, the 1515+ would be well equipped to handle 3 streams of 25Mb/s (possibly more)

The machines with a single ethernet port still need to connect to the internet when not being used for video capture. If i connected just one of the synology ports to the switch, would this then allow for the other machines to connect online through it?

Having never setup static IP addresses before, i have found this simple article online to help me (http://www.howtogeek.com/howto/22161/how-to-set-up-a-static-ip-in-mac-os-x/) Is this what you were advising?

Thanks again for your help.


Return to posts index

alex gardiner
Re: should my NAS be dropping frames when capturing PAL footage?
on May 1, 2016 at 9:50:10 am

Bob is right. Remove that switch from the equation!

Try connecting each client to a dedicated port on the 1515+ ( it looks like it has 4 available). In fact, it is generally a good idea to have a separate network for video work. Unless you have a switch that is known to work for this kind of thing, try to avoid using one.

Simple things to look at...

* What does Blackmagic Disk Speed Test report for offending network drives? (not going to tell you much, but worth a look - should easily hit 110MB/s over gigabit)

* What application you are using for capture?

Generally try to be on a later OS X release if you can (Yosemite or newer, although assuming you are).

I think Synology use a Samba 4 server, but I don't own one, so can't check. If so, you will find later OS X releases tend perform better over SMB, for various reasons. Your synology box can probably do AFP & NFS as well, which might be worth a try.

The truth is your milage is going to vary.

Unfortunately as already mentioned, it may be that the 1515+ is not up to the job. A customer of ours had two for general near-line purposes and from what I remember the performance was rather average.

alex@indiestor.com
Open Source Shared Storage


Return to posts index

Chris Craig
Re: should my NAS be dropping frames when capturing PAL footage?
on May 2, 2016 at 2:40:07 am

Hi Alex and thanks for your reply

I have done what was suggested by Bob, and have connected each lan to the 4 available ports on the synology. I have run the blackmagic speed test and there is no noticeable difference in the write read resuts. They are coming in at around 104/105MB/s for PAL and around 123 for NTSC.

I have not yet assigned static ip addresses

Im using the latest OSX and have been using the latest version of premier to capture. I also use vidi on one machine as i dont have an additional adobe licence and its a freeware program purely for capturing video. I used to capture using iMovie, but since moving to Synology, it does not permit capturing to this type of drive.

The advertising on the synology webpage suggests write speeds of upto 400MB/s so i have detainaly mis-intrepreted that.

What should i then be looking at to purchase for my needs?

Thanks a lot


Return to posts index


Bob Zelin
Re: should my NAS be dropping frames when capturing PAL footage?
on May 2, 2016 at 8:13:32 pm

Hi -
there is nothing that you can buy. The theoretical bandwidth of 1G Ethernet is 125 MB/sec. In real life you are lucky if you get 100 MB/sec over a 1G connection. Without a 10G connection, you cannot get any greater than this.

400 MB/sec is the TOTAL bandwidth available on your Synology box. Want more total bandwidth, buy a box with more drives in it.

Bob Zelin

Bob Zelin
Rescue 1, Inc.
bobzelin@icloud.com


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]