this is what I tested so far:
- Same hardware: booted into Ubuntu Live System (USB Flash Drive). Mounted NAS. "pv /nas/file > /dev/null" also gets me 105 MB/s. Same result with a ramdisk. No problems at all.
- Took the NIC and put it into an older computer running Windows 7: Works perfectly. 105 MB/s
So that obviously leaves these conclusions:
- The NIC is not defective.
- The hardware of the system (running Win8) is not defective.
- The problem must be a software issue.
I guess I'll have to test the NIC with a clean install of Win8 and/or with a clean install of Win7.
Today I tried enabling "Jumbo Frames". I enabled a frame size of 9014 bytes both in the settings of the Intel NIC and the network interface of my NAS.
The problem of lag is gone. But at the same time the speed isn't really what I was looking for. And it's not really constant:
This is what it looks like on my notebook using the exact same setup (cables, switches, NAS):
Next test: Ramdisk
Ok, obviously my OCZ SSD performs much worse than my Samsung 830 SSD in the notebook. So I tried using a ramdisk to check the network throughput.
Ramdisk, jumbo frames disabled: heavy lags...frozen screen for seconds, slow througput:
Ramdisk, jumbo frames enabled (9014 bytes): no lag, perfect speed:
So, I guess this is a solution I can live with. But in the end I still don't understand why the NIC works perfectly with Windows 7 on another machine and with Ubuntu on the same machine but causes so much trouble on Windows 8.
Thank you for taking the time to run these tests and sharing your results. We are close to releasing an updated driver for your adapter. If everything goes well, I should get an updated Intel® Ethernet Connections CD posted by next week at http://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=22283. If you click on the link before the file is posted you will get a page not found message. I plan to come back here and post something when the link is live, but I wanted to include the link in case I don't get this thread updated right away.
I don't know if the updated driver will help with your issue or not. Let me know if the new driver helps or not. If not, I will look into the issue in more detail.
Message was edited by: Mark H @ Intel The CD link in this message with the new software and drivers is now live.
Thank you very much for your answer. I really appreciate it.
Of course I will come back here and report any new results.
I just installed the latest driver (220.127.116.11) and the lags seem to be gone.
But there still seems to be a big difference between jumbo frames on/off. Basically I get the same results as seen in the latest images I posted, just without lags.
So, for me it's ok, because I have no problem using jumbo frames.
Thanks a lot.