On Thu, 18 Sep 2014 12:38:39 -0400, "(PeteCresswell)" wrote:

Per Char Jackson:
I know you're asking about packet size, but others have answered that so I
wanted to suggest something else. The faster speeds make me think you were
testing on a Gigabit network, while the slower speeds make me think you were
testing on a Fast Ethernet (100 megabit) network. Since the throughput speed
of any connection is only as fast as the slowest link, is it possible that
the second set of tests were run at 100 meg?

The reason I ask is that I've had that happen to me.

You are correct in that I *think* I'm running gigabit....

Was thinking that something in the network might be dragging me down to
100, so I ran the test with the PC and NAS plugged directly in to the
router and everything else disconnected.... but got the same results.

Which begs the question, is the router's embedded switch running at Gig
speeds? And did it negotiate Gigabit connections to the NAS and the PC? :-)
If either of those connections didn't negotiate properly, then the overall
connection won't be GigE. I thought you might say that you connected the NAS
directly to the PC as a test. If both are GigE-capable, they'll properly
figure out the MDI/MDIX question. Windows will tell you, in Task Manager,
what speed it's connected at.

Never mind, I may be chasing rabbits. It's just that GigE requires all of
the cable pairs in the Ethernet cable to actually be connected properly,
while FE (100M) doesn't, so a bad cable can drop you back to FE.

But as a second test, try using iPerf or jPerf. Both are free and both work
well. I especially like jPerf, but I don't remember why. Neither tool writes
anything to the filesystem during the test, so it's just a 'network speed
test' type of tool.

A couple of years ago I was getting 300-450 megabits/sec on one segment of
my LAN, so I assumed it was the cheap $6 NICs I was using. Using jPerf,
though, the test reported 960 mbps+, so it wasn't the NICs. In my case, it
was a slow/dying drive at one end.

--

Char Jackson