View Full Version : Different LAN upload and download speeds

09-03-2013, 12:53 PM

Can anyone help with a weird LAN issue? I have just purchased a new NAS and am in the process of transferring files across my home LAN. All was working fine, but suddenly the upload speed dropped through the floor.

I downloaded LAN Speed Test, and got the following results:

Version 1.3.0
OS Version: Mac OS X 10.8 (Mountain Lion)
Date: 09/03/2013
Time: 20:45:15
Program Parameters: 0
High Performance Timer: 0.000000001

Test File: /Volumes/Scott/NW_SpeedTest.dat
Write Time = 52.4916106 Seconds
Write Speed = 3.0481040 Mbps
Read Time = 4.2251992 Seconds
Read Speed = 37.8680400 Mbps

Any ideas? Anything I should be looking for?



Scott DeLeeuw
09-03-2013, 02:41 PM
Hi Scott, those are some slow write speeds. Which NAS is it and how do you have the drives configured?

09-04-2013, 07:23 AM
Hi Scott.

The NAS is a Synology ds212j configured in a RAID 1.

Was working fine to start with, then during an overnight transfer of 150+ Gb the write speeds dropped through the floor.

Have tried restoring the NAS with no improvement. Have also rebooted the router but again no impact.


Scott DeLeeuw
09-04-2013, 07:54 AM
RAID 1 write speeds are always going to be a little slower, but they shouldn't be that slow.

The best performance metrics I could find was the SmallNetBuilder Synology DS213+ benchmarks. The DS212j is a lower performance model than the DS213+, so the numbers shouldn't be as high, but have a look here.


The interesting thing to me is the directory copy performance. All NASes are pretty low for that when you look here. http://www.smallnetbuilder.com/nas/nas-charts/bar/27-naspt-directorycopy-to

It shouldn't be low in LAN Speed Test though as that is a file copy. What is your network setup, are your devices full duplex? I forget if the the DS212j has a Write-cache checkbox (I believe it does), did you make sure that is enabled?

Pete Totushek
09-07-2013, 06:30 AM
Hi Scott,

Check out this post...

It's a shot in the dark. Also, does your NAS allow you to check the condition of each drive? In a RAID 1 setup (and depending on the NAS software), if one drive is faulty or takes extremely long to write, the other drive usually waits until the problematic drive is done before allowing more writing. In otherwords if one drive is being problematic, performance will be horrible even though you have two drives.

Good luck!