10gbe X520-D2 slow speeds

[pintu1228]

Hi, I need some help figuring out why my 10gbe speed is slow. Here are my freenas and windows 10 specs:

Windows 10:

i7-930
Asus P6x58d-e
32GB G.Skill F3 DDR3
250GB Samsung Evo 840
Seagate Desktop SSHD 2TB
Geforce GTX 980
Intel Pro/1000 PT
Intel X520-D2

FreeNAS:

Dual Intel X5650
Supermicro X8DTE-F
Intel 40GB ssd for freenas boot
8 WD Red drives in RaidZ2
LSI 9211-8i flashed
Intel X520-D2


Both 10gbe intel cards are connected via fiber cable. I have run iperf on both the client and freenas box and the results are terrible. When I transfer files from freenas box to windows pc, it starts out at 300Mb/s but then drops to 0 and slowly climb to 100 Mb/s before it finishes, if I do this same transfer via FTP I get 51 MiB/s. On the reverse from windows to Freenas, I get writes 52 MiB/s via FTP.

Any help to figure out why 10gbe speeds are awful would be great.

Thanks

 

[Ericloewe]

What FreeNAS version?

 

[pintu1228]

Freenas verison 11.1-RELEASE

 

[pintu1228]

Any other ideas or comments on what to try to fix issue?

 

[Ericloewe]

This could very well be something weird on the Windows side (firewall, other antimalware stuff, etc.). To at least try to narrow it down, you could try a different client OS and see if performance is closer to what you expect.