Help troubleshooting Netgear NV+ (works fine) vs DNS-321 (choppy video)

[flight23]

I have a Mac Mini running plex attached via cat5e cable through a Dlink DG-2208 gigabit switch to both a Netgear NV+ and D-Link DNS-321. Videos streamed from the Netgear including 1080p files play fine, however the same exact videos streamed from the D-Link run choppy.

I have tried various jumbo frame rates, however the Netgear is set to only 1592 and works fine. On the D-link I tried disabling jumbo frames and setting the MTU to 3000 and 9000 and editing the same parameter on the Mac Mini with no success.

The Netgear transfers run at about 4-5MB/s, but the D-Link ones only seem to hit about 2MB/s.

Any suggestions? I am by no means a networking expert so I dont even know how to troubleshoot this.

 

[thiggins]

You should not need jumbo frames to support even 1080p video. I suggest you don't use it.

How are you measuring the transfer rates?

The NV+ can do around 25 MB/s reads in RAID5 or FlexRAID. The DNS-321 can do around 11 MB/s. Both are with Gigabit Ethernet connections.

Depending on the encoding, 1080p video can run 20 - 30 Mbps (2.4 - 3.8 MB/s). So either NAS should handle a single stream. But busy content scenes can push the bit rates higher.

 

[flight23]

Thanks for the reply. I just estimated the transfer rates by seeing how much transferred in one minute and divided by 60.... I dont have actual software to measure it. I have the NV+ set up as XRAID but I havent gotten anywhere near those transfer rates you mentioned even with gigabit ethernet. I have read the DGS-2208 throttles everything down to 100Mbit if you have a single 100Mbit device connected, but I have only gigabit devices connected.

The choking does only seem to occur in scenes with a lot of movement, but at least once a minute on average. I tried disabling jumbo frames on everything but the choking actually became worse without it. What else can I try/test to see where the problem lies?

 

[thiggins]

As long as a Gigabit switch isn't malfunctioning, it will properly support Gigabit and 100 Mbps connections simultaneously.

If you want to eliminate the switch as a problem, either disconnect any 100 Mbps devices or directly connect the computer and NAS after assigning static IP addresses to each. (You don't need a "crossover" Ethernet cable for Gigabit Ethernet. The ports will figure out the proper way to connect.)

 

[tipstir]

Sounds like this switch is faulty or is overheating? If you only have gig devices connected to it, but then it drops down to 100mbps could be duff ports. Try different ports and see if it still does it?