[doldi]

"smsc95xx: Experimental: Enable turbo_mode and packetsize=2560 by default" works fine for me,
but if i have a Netgear GS108 switch betweem router and Rpi3 or 2,
BR will stuttering an 1Gb/s - must downgrade to 100Mb/s speed.

You could try adjusting the packetsize number. I'd suggest you add 512 and test again, and repeat that if it doesn't help (up to, say 8192).

Thank You popcornmix, have add and add and now i'm on 8192,
but this f***ing Netgear would not be interested about them - the Blue Ray Menue don't read fluently over smb 1Gb/s.

I think i need a managed Switch ...or Web-Smart Switch.