[Philipp Meier]

Would love to re-visit this topic. Also using the Promise SanLink2 and getting decent performance connecting to a Windows Server 2012 R2 with a 36 drive RAID 60. Internally the RAID gets 3,000MB/s read and write.

A Mac Pro 2013 with a Promise SanLink 2 currently gets 630MB/s writes and 840MB/s reads with the following systlc config:

net.inet.tcp.doautorcvbuf=0
net.inet.tcp.doautosndbuf=0
kern.ipc.maxsockbuf=8388608
net.inet.tcp.sendspace=4000000
net.inet.tcp.recvspace=4000000
net.inet.tcp.maxseg_unacked=8
net.inet.tcp.delayed_ack=0
net.inet.tcp.win_scale_factor=7

Before that I used these:

net.inet.tcp.doautorcvbuf=0
net.inet.tcp.doautosndbuf=0
kern.ipc.maxsockbuf=8388608
net.inet.tcp.sendspace=4194304
net.inet.tcp.recvspace=4194304
net.inet.tcp.maxseg_unacked=32
net.inet.tcp.delayed_ack=2
net.inet.tcp.win_scale_factor=7

That got us to 632MB/s write and 828MB/s read. Seems like decreasing the unpacked value to 8 and setting ack value to 0 squeezed out just a little bit more. Possible that it was just a fluke, though.

Anyways, the performance isn’t bad but the write are much slower than the reads. Again the RAID is not the bottleneck as it can pull 3000MB/s writes. Wondering if there are any additional settings on either the OSX or windows side that can be tweaked to improve the speed?

SMB signing is already turned off and Netbios over TCP is turned on on the Windows NIC. Jumbo frames enabled on Client, Server, and Switch. Switch is a Netgear M7100-M24X.

[Philipp Meier]

I’m not sure how this conversation got into a discussion about network turnkey solutions when the question was a very basic problem about OS X slowing down 10Gbe connections after a while. I actually believe this to be a bug in OS X as we are too experiencing random slow downs on 10GBe adapters. This has nothing to do with the server or NAS connected on the other side. It’s about the client side.

I had a hunch that it had something to do with 10Gbe over thunderbolt but it seems as if Chris is also experiencing this with regular PCI cards.

Chris, have you made any further discoveries since December? It would be nice to get to the bottom of this and report the issues to Apple.