this is basically my reply in the qnap forums (http://forum.qnap.com/viewtopic.php?f=182&t=60184&p=284960#p284960)

as the Intel X540-T2 card is not yet officially supported by QNAP i asked QNAP for a statement via email .. but as the answer did not result in something like “yeah, you know, it works .. but it’s not yet officially supported” but in a link to the compatibility list (http://www.qnap.com/en/index.php?lang=en&sn=4061 where the card is still not listed but it’s predecessor the X520-T2) i decided to simply buy two of these cards and test them …

i did tell the vendor before ordering that i would test one card first and if it does not work (in the QNAP) i would send the second one back and order a X520-T2 (and wait one month due to delivery bottleneck) … i would then have used the X540-T2 in the computer connected to the QNAP and the X520-T2 in the QNAP itself …

so a couple of weeks ago i did the following:

  • install one X540-T2 card in the TS-879U-RP (Firmware 3.7.2 Build 20120719)
  • connected both ports with each other (as of gigabit standard no more cross cables are needed as the ports figure it out themselves)
  • the admin interface then showed “10 GBit” next to the card .. so it seemed to work just as wanted
  • installed the other card in the computer
  • configured both dual cards to trunks
  • set up a private ip address on each trunk (192.168.1.XXX) as they are direct attached and then also won’t interfere with the LAN network

since then the system is running without any problems and is connected via iSCSI to the computer …

i ran a hdd test (burst speed with SAS 15K disks) : with a 1 GBit trunk was 80 MB/s … with the 10 GBit trunk we now get 360 MB/s …