NAS to Windows 40Mb/s - NAS to Linux 80 Mb/s

[geekmiki]

Hi,

For the past couple of days I've noticed the strangest problem on my LAN, that I can't seem to solve:

Hardware:
-Linux server, running Ubuntu 14.04 with several file sharing services (NFS, SMB, FTP, etc.)
-Desktop PC (Core i5, 16GB RAM, Intel NIC) running in dual boot Windows 8.1 and Archlinux

I did the following test:
-Transfer a 10GB file via FTP from the server to the desktop from Windows and Archlinux, both with Filezilla and to the same harddisk (that has a Win and a Linux partition)

The results were as follows:
-Windows: ~35-40 Mb/s
-Archlinux: ~70-80 Mb/s
Same file, same client, same server

While transferring the file under Windows, I had 2 scenarios that happened randomly (tested the transfer several times):
1. Everything runs smooth and the transfers seems to be capped at 40 Mb/s
2. Sometimes the speeds went up to 70 Mb/s but then I had major OS freezes/slowdowns. None of the programs crash, the transfer continues at 70 Mb/s, but the whole OS is unresponsive.

In scenario 2, I tried to eliminate the software problem by trying the same transfer with WinSCP, and then the speed were also maxed out at 40 Mb/s.

Any clues on this issue? It seems like Windows somehow is capping the transfer speeds.
Also to note that this issue is recent and before that I was able to reach the same LAN speeds both under Windows and Archlinux.

Thank you in advance!

 

[Nullity]

While the Windows PC is transmitting, what is the CPU usage? What program/service is using the most CPU?

Is Windows running some antivirus or automatic backup service that is overloading your PC or perhaps hindering your hard-drive's maximum read/write speeds?

Do you have all the NIC off-loading features enabled?

Is the Intel driver up to date?



Good choice with ArchLinux btw. Arch is my favorite distribution, by far.

 

[geekmiki]

Hi,

Thanks for your reply!

-CPU load is around 15-20%, the program using the most CPU is Filezilla, taking up 13-15%
-The only antivirus is the built-in AV in Win8
-NIC offloading features? Could you explain that one a bit more? I haven't looked into that yet.
-Intel NIC drivers are up to date

Thanks again!

 

[Nullity]

NIC off-loading is way to drop your CPU/system load by allowing a quality NIC do more of work itself, like checksum off-loading. Wikipedia can undoubtedly explain it better than I can though.

Sometimes off-loading can be buggy, so if it is already enabled, perhaps try disabling it.



The most alarming part of your post was when you said Windows would freeze/stutter during file transfer. This says to me there is an obvious bottle-neck somewhere. I am assuming hard-drive read/write speed, possibly caused by stupid antivirus scanning everything before it gives you access.

 

[geekmiki]

As strange as it sounds, everything is back to normal without having changed any parameter... Windows mysteries...