OS X 10GbE
Been trying to improve 10GbE performance on my iMac this evening, have been working with a number of VMs and large datasets the last few weeks and the slight speed boost would have been nice on file transfers I just haven't had the time to experiment.
Found some pretty informative posts for OS X Mavericks here
Performance Tuning the Network Stack on Mac OS X Part 2 | Rolande's Ramblings
And just in case his blog ever disappears.. his suggested settings are
Code:
kern.ipc.somaxconn=2048
net.inet.tcp.rfc1323=1
net.inet.tcp.win_scale_factor=4
net.inet.tcp.sendspace=1042560
net.inet.tcp.recvspace=1042560
net.inet.tcp.mssdflt=1448
net.inet.tcp.v6mssdflt=1412
net.inet.tcp.msl=15000
net.inet.tcp.always_keepalive=0
net.inet.tcp.delayed_ack=3
net.inet.tcp.slowstart_flightsize=20
net.inet.tcp.local_slowstart_flightsize=9
net.inet.tcp.blackhole=2
net.inet.udp.blackhole=1
net.inet.icmp.icmplim=50
Thunderbolt Bridge
First up I returned to the thunderbolt bridge between my iMac and MacBook Pro, reading the reviews on the internet this has had very mixed reviews with some users reporting less than gigabit speeds! But figure it could be worth spending a little bit of time on seeing as quite often I need to copy VMs etc across from my NAS to the laptop if I'm working away.
Applied the above performance tweaks and ran some tests.
iperf results were pretty disappointing even using a range of configurations, here, typically seeing 2.1Gbits/sec to 2.2Gbits/sec
Setup a 6GB RAM disk on both machines and created a blank file of 5.37GB copying over apples AFP sharing service it transferred in 23 seconds. That pretty much matches my iperf results.
Tried the same test using SMB but the copy simply failed due to an unexpected error!
Figured I'd try the Blackmagic speed test utility over smb
While they are not quite 10Gb/s speeds I have a feeling I'm not going to see much better over thunderbolt. I do wonder if the older generation TB1 is the limiting factor here.
10GbE Network on OS X
Revisiting my performance issues on my iMac's connection to my NAS iperf is only returning about 3.6Gbit which is around 429MB/s, almost enough to max out my SSD which I'm more than happy with to be honest.
Testing one of my iSCSI volumes results the following, not the best write performance!
Copying a 50GB image file from my newly upgraded Ubuntu NAS, now running 14.04 LTS. Upgraded due to the native support of the SMB3 protocol only to find out OS X is still running SMB2!
I see varying speeds from the NAS to my local NAS. Low as 90MB/s high as 292MB/s (note these are only measured a combination of iStat menus and activity monitor on OS X and nmon on the NAS)
Know this probably isn't the most accurate way of measuring this, but shows the inconsistent speeds
And copying the file back to the NAS
Seems to be around the 280-290MB/s mark in each direction.
Also tried copying from NAS to a RAM disk with a 10GB file, same speeds. Going to try install Windows 8.1 on a box tomorrow and see how well that performs using SMB3, expecting 500-600MB/s mark which I'd usually see with sequential transfers server to server!
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