The problem solved. Just installed PCI-e card (TP-LINK TG-3468 for 10$) on Realtek RTL8168E. No latency spikes (as I wrote before,I did not noticeproblems anyway), and up to 117 mbytes/s at file copy via SMB. With Jumbo Frames this card loads one core of i5-3470 (3.4 GHz) by 40-50%.
Speeds and CPU load like the same with Intel NIC.
