Slow ISCSI performance on Windows 10

So i have this diskless / pxe booting environment with 28 clients using a program called ccboot. Client is using kabini based board A68n-5200

Essentially it's 28 clients communicating using ISCSI protocol with a single diskless server running win server 2012 r2.

Problem is, if i use win 10 image, performance is very sluggish and laggy, and it doesn't happen on win 7.

What could be the cause? Both images have identical configs and programs installed.

The board itself stated on their page that win 10 is supported and provide drivers for it http://www.biostar.com.tw/app/en/mb/introduction.php?S_ID=820#download

I could only think of automatic smb3 between win server 2012 and win 10, since it shouldn't happen on win 7.. but it should only affect smb protocol, not iscsi.

Check TCP performance with NTtcp & iPerf, your NIC should do wire speed. NIC drivers and TCP default settings are different for Win7 & Win10, so it might be your case.

P.S. Try to increase an amount of iSCSI sessions.