Networking performance issues

[Strelitzia]

Hi All,

I hope someone can help as I'm fairly new here.

I currently have 2x NAS drives (Synology boxes) that are talking to each other over powerline home networking (AV500). I also have an iMac connected so using Finder to view/transfer files (AFP I think? I'm not so techy regarding protocols used).

The issue I have is that when transferring files from one NAS to the other I'm averaging speeds of 3MB/s. One of the NAS drives is plugged straight into the router (a Virgin superhub which is the Netgear CG3101D). So as I see it I have a Gigabit network enabled. My Mac has the option of setting Jumbo frames however I can only see the hard drives when setting this option, the folders can't be seen. If setting to 1000baseT on 1500 MTU on full duplex the folders on both NAS drives are viewable. And both NAS drives are Jumbo frames enabled.

The NAS drives should have 60MB-100MB read/write speeds respectively (of course they won't get these but the loss should be max. 20% I would have thought).

I'm not sure if using a switch would help as basically the Hub is acting like a switch? Especially as there is only 1 computer involved.

Does anyone have any ideas where I am getting this annoying bottleneck, where I should be seeing speeds of 15-20x faster). Or how to improve the network short of hard wiring cables.

Many thanks for any help given,
Sean

 

[overdrive31]

Looks like the powerline networking is the problem. Are you certain the powerline adapters are on the same 110V leg? If on separate legs, the performance can suffer considerably.

 

[thiggins]

First, get a baseline throughput measurement with both NASes plugged into the Gigabit switch. Disable jumbo frames and leave MTU settings alone. They are more likely to screw you up than help you.

500 Mbps powerline is going to provide around 80 Mbps (10 MB/s) tops (powerline charts). 3 MB/s seems low, but isn't out of the question.

It doesn't make any difference whether the powerline adapters are on different AC phases. That problem was solved long ago. AFCI breakers can definitely knock down throughput as can noise. See Slow HomePlug? Five Ways To Boost Powerline Network Speed

 

[seanmnaes]

If you are using the Mac Finder to copy between the two then it is going transfer everything from the first Synology to the Mac and then to the second Synology. That plus powerline speed could pretty easily add up to 3 Mega Byte speeds.

You might be better logging into the Synology web interface and transfering between the two like that. That would make them transfer directly between the two. Faster, but don't expect blazing speeds. It will probably top out somewhere around 10 Mega Bytes per second. Mostly limited by the Powerline adapter.

If you could attach both NAS directly to the super hub it would probably go a lot quicker.

-Sean