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I have upgraded Ubuntu 13.10 with the most recent packages offered, including kernel 3.11.0-15-generic. I have gigabit lan and I noticed that when I uploading large files (~2-4GB) to my Ubuntu "NAS", the upload speed is very bad (8-9MB/s). Before upgrade of the kernel it used to be ~50MB/s. I made several tests, but the result was still very slow upload. Download speeds are fine - ~50MB/s

I booted from Ubuntu 13.10 live usb - upload speed was good there - ~50MB/s (there was 3.11.0-12-generic kernel).

Then I booted my Linux with selecting older kernel 3.11.0-12 in Grub menu. --> with this kernel the upload and download speeds are fast - ~50MB/s. So I assume the problem is in the kernel 3.11.0-15.

I have this ethernet controller: Ethernet controller: Qualcomm Atheros AR8151 v2.0 Gigabit Ethernet (rev c0) Using this module: atl1c

Any ideas what's wrong with the new kernel?


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I did one test once more - a clean installation of Ubuntu 13.10. Ethernet upload speed was fine - ~50MB/s, but then Ubuntu asked for upgrade of the packages and installed kernel and after that the upload speed is again only ~8-9MB/s --> so bad. –  user241281 Jan 30 at 13:10
Update: I installed this kernel: 3.12.0-031200-generic, but again the same behaviour - slow upload speed. So either I stick with the kernel 3.11.0-12-generic or I will buy other NIC. –  user241281 Jan 30 at 14:53

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