IMac network speeds.

[Mac]

Heres one for you as its got me stumped.

Set up.
PC direct connect cable to NAS Server.
1Gig cards in PC and NAS Server.
File transfer speeds about 90 - 110M per sec. indicating 1G connection

unplug network cable from pc and plug into IMac

New shiny 5K IMac
1Gig card set up for 1gig connection,
File transfer speeds, 5-10 M per sec.

Indicating a connection of 100M as opposed to 1000M

Any ideas how to force it to 1000M.
I,ve tried everything, changing jumbo frames from 1500 to 9000,
allowing it to auto set up everything, manually setting everything up,
changing the cables, reversing the cables,
plugin it in via a 1G switch,
1G switch shows IMac is connected at 1G as is Nas,
but file speeds indicate 100M

Im pulling out what little hair I have.

Mac.

[The Thing]

The Imac may be more fussy about cables. I am having a similar problem and have some cat6 patch cables on order as I've tried everything else.

[Mac]

Well I have just remade another new patch cable and tested it it still doesn't like it, I might have to follow your lead and shell out for a cat6,
Which is really pointless!

Just another annoying quirk of the Mac (os.)   

Mac.

[Mac]

***UPDATE***

Sorted.
Its not the cable or the network thats the problem, its my Server.
I just copied a few files off of my PC directly onto the mac and I was getting 113M quite happily.

I dont know what the issue is as i have twin 1G ports set up on the NAS, but it looks like ill just have to leave it all running untill everything is coppied over and i can update the nas drive

Looks like its going to be a long one.

5TB of data to copy over at 100M speeds, 

Oh well.

Mac.