[SOLVED] 10GbE: SMB Direct and SMB Multichannel on Windows 8.1

[Asmodian]

Does anyone know a method of enabling SMB Direct and SMB Multichannel on Windows 8.1? I have two dual port NICs which support rdma and rss but I am running Windows 8.1 not Server 2012 R2. I would love to have a 20Gbps connection between my workstation and file server.

I am able to enable rdma and rss seems to be working, I can get up to 1.1GB/s over one cable with very low CPU usage on all cores (a few % on each). Everything I can find says multichannel NetworkDirect requires Server R2 but I am hoping for an undocumented hack.

I don't think it is worth running a Server OS for my use case and I am sure there isn't a technical reason for its absence.

How I got here:

After getting my first 10Mbit ethernet card when going to college I have been happily upgrading my home LAN fairly regularly. I remember getting my first (very hot) 1Gbps ethernet card quite a while ago. Sadly 10GbE seems to be quite hard over Cat 6a and 10GbE has been a long time coming to home users (i.e. affordable). I expected it years ago when I was setting up my first 1Gbps network; replacing 100Mbps which had replaced 10Mbps.

I decided I should check on 10GbE prices again and after a scan of ebay I convinced myself 10GbE is finally almost affordable. After a little deliberation I decided to go with SFP+ instead of 10GBASE-T. Two Mellanox Technologies MCX312A-XCBT ConnectX-3 cards and two SFP+ Direct Attach copper cables were under $500. 10GbE switches don't seem to be affordable so I guess I should say "very small LAN". Anyone know of a decent 5 port SFP+ 10GbE switch?

Mellanox says they only support Windows Server OSes but the drivers for Server 2012 R2 work well in Windows 8.1. With one 10 Gbit connection to my server I can pull ~950 MB/s, the best network file copy I have seen is 1.1GB/s. Now my RAID array and other server drives feel like they are local. It has been a long time since my network has felt this good. However there is a free port and I have another cable. My research turned up SMB 3.02 and now I want 20Gbps. I have to ask, "Why not for Workstation users as well!"

As a bonus SFP+ is very flexible; I could plug a 10km 10Gbps fiber line into the other port instead.

 

[Asmodian]

Of course I figured it out right after posting.

I simply had the name for what I wanted confused; I will call it too much searching too late.

With a hint from azazel1024 the name is simply "SMB Multichannel" and Google quickly found:

PowerShell

Set-SmbServerConfiguration -EnableMultiChannel $true
Set-SmbClientConfiguration -EnableMultiChannel $true

and the respective:

Set-SmbServerConfiguration -EnableMultiChannel $false
Set-SmbClientConfiguration -EnableMultiChannel $false

Running the Server enable command enabled it exactly like I was hoping for, an effective 20Gbps ethernet link.

The MS Technet page says it should be enabled by default but maybe not for Server on Windows 8.1?
edit: It is key to not have any incompatible paths, for example an Intel-on-motherboard 1Gbps link to a router on both systems.

Of course this is only for SMB so for 10Gbps links it is only useful if you have really fast storage in another computer, a few SSDs in RAID0 for example. It would also be very nice with two 1Gbps links even for accessing a single HDD.

 

[azazel1024]

Glad I could help from another thread