I recently upgraded my home network to include a central switch with a pair of SFP+ ports. The switch I got was the 48 port 500W model seen here:
https://www.ubnt.com/unifi-switching-routing/unifi-switch/
I got a pair of Intel X520 NICs. One installed in my FreeNAS server and connected to the switch via a SFP+ twinax cable.
The other X520 is installed in my Windows 10 workstation and connected to the switch via a 50 ft OM3 cable.
iperf running from the workstation shows the following:
When I increase to 6 threads, throughput almost doubles:
So my first question is, why does single thread performance only appear to be about 50% of what the link should be capable of?
When I copy from the server to the workstation, I'm only getting about 600 Mbps as seen here:
When I go the other way, I get about 2 Gbps as seen here:
The workstation has 4 Samsung 128GB 840 PROs in RAID0 so that should not be the bottleneck. Crystal gives me the following:
Any ideas about what the issue might be?
https://www.ubnt.com/unifi-switching-routing/unifi-switch/
I got a pair of Intel X520 NICs. One installed in my FreeNAS server and connected to the switch via a SFP+ twinax cable.
The other X520 is installed in my Windows 10 workstation and connected to the switch via a 50 ft OM3 cable.
iperf running from the workstation shows the following:
Code:
C:\iperf>iperf -p 5001 -c 10.0.1.50 -w 512k
------------------------------------------------------------
Client connecting to 10.0.1.50, TCP port 5001
TCP window size: 512 KByte
------------------------------------------------------------
[ 3] local 10.0.1.53 port 57211 connected with 10.0.1.50 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 5.74 GBytes 4.92 Gbits/sec
When I increase to 6 threads, throughput almost doubles:
Code:
C:\iperf>iperf -p 5001 -c 10.0.1.50 -w 512k -P 6
------------------------------------------------------------
Client connecting to 10.0.1.50, TCP port 5001
TCP window size: 512 KByte
------------------------------------------------------------
[ 7] local 10.0.1.53 port 63293 connected with 10.0.1.50 port 5001
[ 8] local 10.0.1.53 port 63294 connected with 10.0.1.50 port 5001
[ 3] local 10.0.1.53 port 63289 connected with 10.0.1.50 port 5001
[ 4] local 10.0.1.53 port 63290 connected with 10.0.1.50 port 5001
[ 6] local 10.0.1.53 port 63292 connected with 10.0.1.50 port 5001
[ 5] local 10.0.1.53 port 63291 connected with 10.0.1.50 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 2.42 GBytes 2.08 Gbits/sec
[ 4] 0.0-10.0 sec 1.54 GBytes 1.32 Gbits/sec
[ 5] 0.0-10.0 sec 1.53 GBytes 1.32 Gbits/sec
[ 7] 0.0-10.0 sec 1.53 GBytes 1.32 Gbits/sec
[ 8] 0.0-10.0 sec 2.42 GBytes 2.08 Gbits/sec
[ 6] 0.0-10.0 sec 1.53 GBytes 1.32 Gbits/sec
[SUM] 0.0-10.0 sec 11.0 GBytes 9.42 Gbits/sec
So my first question is, why does single thread performance only appear to be about 50% of what the link should be capable of?
When I copy from the server to the workstation, I'm only getting about 600 Mbps as seen here:
When I go the other way, I get about 2 Gbps as seen here:
The workstation has 4 Samsung 128GB 840 PROs in RAID0 so that should not be the bottleneck. Crystal gives me the following:
Any ideas about what the issue might be?