Christopher Chan wrote:
On Friday, June 24, 2011 02:33 PM, Emmanuel Noobadmin wrote:
On 6/24/11, Christopher Chanchristopher.chan@bradbury.edu.hk wrote:
On Friday, June 24, 2011 01:20 AM, Emmanuel Noobadmin wrote:
First bottleneck was discovering the max MTU allowed on these is 7K instead of 9K but googling seems to indicate that the RTL8168B is only capable of 4K frames.
Yeah, the 8168C goes up to 7k. Some 8168B go up to 6k.
In cases like this where there are conflicting sources of information regarding the max MTU of a NIC, what would be the correct way to determine the actual max MTU? I figured the 7K limit basically by doing a binary search with the ifconfig mtu commands. But is the this figure simply what the driver will accept for the controller it identified or is that the actual hardware limit?
Given that these are the limits from Realtek's own Windows drivers, I'd say they are hardware limits and different from chipset/rev.
This post: http://ubuntuforums.org/showthread.php?t=1628575 Suggests that Windows and OpenSolaris were pusing 3x more then his current Ubuntu. This would suggest Linux driver problem. That is why I suggested ElRepo driver.
I just checked my server and my desktop. They both have 8168B NIC. Server integrated and desktop has PCI-X if I am not mistaken (I on laptop 35km away) with what seams to be stock kernel driver r8169.
When I first bought Gigabit switch (cheap Intex) they were both plugged next to each other. CentOS -> CentOS NFSv4 large files copy gave me sustained speed of ~250Mbps (~31 MBps), without even touching the settings, which is good for HDD(s) I had back then.
I can not comment on JUMBO frames, never needed them. But it would be nice to see if there is difference with ElRepo drivers.
Ljubomir