Slow send to server... receive = fine

Page 2 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.

andyinv

Member
Sep 14, 2015
32
0
0
So the desktop gets

Code:
E:\iperf>iperf3 -c acer
Connecting to host acer, port 5201
[  4] local 192.168.1.213 port 50690 connected to 192.168.1.11 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec   768 KBytes  6.29 Mbits/sec
[  4]   1.00-2.00   sec   512 KBytes  4.19 Mbits/sec
[  4]   2.00-3.00   sec   512 KBytes  4.20 Mbits/sec
[  4]   3.00-4.00   sec   640 KBytes  5.24 Mbits/sec
[  4]   4.00-5.00   sec   512 KBytes  4.20 Mbits/sec
[  4]   5.00-6.00   sec   512 KBytes  4.20 Mbits/sec
[  4]   6.00-7.00   sec   512 KBytes  4.19 Mbits/sec
[  4]   7.00-8.00   sec   640 KBytes  5.24 Mbits/sec
[  4]   8.00-9.00   sec   512 KBytes  4.19 Mbits/sec
[  4]   9.00-10.00  sec   640 KBytes  5.24 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  5.62 MBytes  4.72 Mbits/sec                  sender
[  4]   0.00-10.00  sec  5.44 MBytes  4.57 Mbits/sec                  receiver

The laptop gets:

Code:
E:\iperf>iperf3 -c acer
Connecting to host acer, port 5201
[  4] local 192.168.1.185 port 62076 connected to 192.168.1.11 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  5.00 MBytes  41.8 Mbits/sec
[  4]   1.00-2.00   sec  4.88 MBytes  41.0 Mbits/sec
[  4]   2.00-3.00   sec  5.12 MBytes  42.9 Mbits/sec
[  4]   3.00-4.00   sec  5.62 MBytes  47.2 Mbits/sec
[  4]   4.00-5.00   sec  5.88 MBytes  49.3 Mbits/sec
[  4]   5.00-6.00   sec  5.62 MBytes  47.1 Mbits/sec
[  4]   6.00-7.00   sec  5.50 MBytes  46.1 Mbits/sec
[  4]   7.00-8.00   sec  5.88 MBytes  49.3 Mbits/sec
[  4]   8.00-9.00   sec  5.75 MBytes  48.2 Mbits/sec
[  4]   9.00-10.00  sec  5.62 MBytes  47.2 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  54.9 MBytes  46.0 Mbits/sec                  sender
[  4]   0.00-10.00  sec  54.9 MBytes  46.0 Mbits/sec                  receiver
 

sdifox

No Lifer
Sep 30, 2005
100,288
17,904
126
So the desktop gets

Code:
E:\iperf>iperf3 -c acer
Connecting to host acer, port 5201
[  4] local 192.168.1.213 port 50690 connected to 192.168.1.11 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec   768 KBytes  6.29 Mbits/sec
[  4]   1.00-2.00   sec   512 KBytes  4.19 Mbits/sec
[  4]   2.00-3.00   sec   512 KBytes  4.20 Mbits/sec
[  4]   3.00-4.00   sec   640 KBytes  5.24 Mbits/sec
[  4]   4.00-5.00   sec   512 KBytes  4.20 Mbits/sec
[  4]   5.00-6.00   sec   512 KBytes  4.20 Mbits/sec
[  4]   6.00-7.00   sec   512 KBytes  4.19 Mbits/sec
[  4]   7.00-8.00   sec   640 KBytes  5.24 Mbits/sec
[  4]   8.00-9.00   sec   512 KBytes  4.19 Mbits/sec
[  4]   9.00-10.00  sec   640 KBytes  5.24 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  5.62 MBytes  4.72 Mbits/sec                  sender
[  4]   0.00-10.00  sec  5.44 MBytes  4.57 Mbits/sec                  receiver

The laptop gets:

Code:
E:\iperf>iperf3 -c acer
Connecting to host acer, port 5201
[  4] local 192.168.1.185 port 62076 connected to 192.168.1.11 port 5201
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-1.00   sec  5.00 MBytes  41.8 Mbits/sec
[  4]   1.00-2.00   sec  4.88 MBytes  41.0 Mbits/sec
[  4]   2.00-3.00   sec  5.12 MBytes  42.9 Mbits/sec
[  4]   3.00-4.00   sec  5.62 MBytes  47.2 Mbits/sec
[  4]   4.00-5.00   sec  5.88 MBytes  49.3 Mbits/sec
[  4]   5.00-6.00   sec  5.62 MBytes  47.1 Mbits/sec
[  4]   6.00-7.00   sec  5.50 MBytes  46.1 Mbits/sec
[  4]   7.00-8.00   sec  5.88 MBytes  49.3 Mbits/sec
[  4]   8.00-9.00   sec  5.75 MBytes  48.2 Mbits/sec
[  4]   9.00-10.00  sec  5.62 MBytes  47.2 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  54.9 MBytes  46.0 Mbits/sec                  sender
[  4]   0.00-10.00  sec  54.9 MBytes  46.0 Mbits/sec                  receiver


Did you try the usb stick on the laptop.
 

andyinv

Member
Sep 14, 2015
32
0
0
Yeah, already seen that one thanks. Sadly, no effect :(

Tempted to use one of our MS support calls at work, hehe....
 

andyinv

Member
Sep 14, 2015
32
0
0
Did you try the usb stick on the laptop.

Just did that - the problem followed. When I removed it and went back to the laptop wifi, normal performance resumed. So now it looks very much like driver...

EXCEPT.... I've already clean-installed this machine with windows 10 twice, and it can only have pulled the same driver. Which makes zero sense... I'd have noticed the poor upload when sending digital photos to the server...
 

mxnerd

Diamond Member
Jul 6, 2007
6,799
1,103
126
Win10 drivers are not all there yet.
+1


@OP

What brand of WiFi network card causes problem?

RALink has been bought by Mediatek and thier driver support sucks.

Atheros is another one that got bad reputation.
 

andyinv

Member
Sep 14, 2015
32
0
0
This is branded Edumax (nope, me neither), but it's a Realtek chipset. I tried the Realtek drivers, but they're older than what I have. No difference. Device manager shows Realtek drivers in place. Again tho, this worked before..
 

XavierMace

Diamond Member
Apr 20, 2013
4,307
450
126
Out of curiosity, have you consider the USB drivers? Do you get the same transfer speeds to a USB stick on both computers?
 

mxnerd

Diamond Member
Jul 6, 2007
6,799
1,103
126
@OP

I'm not familiar with Wirshark, but I do downloaded your files and open 2 of them.

fastlaptop.pcapng and slowtoserver.pcapng

I find that fastlaptop has much smaller TCP Window Size ranging from 250 to around 2000 yet slowtoserver has TCP Window Size = 64240, maybe this causes the slow down?

I hope experts in anand forum can help explaining.
 

andyinv

Member
Sep 14, 2015
32
0
0
Out of curiosity, have you consider the USB drivers? Do you get the same transfer speeds to a USB stick on both computers?

Now, there's an idea... I have a USB3 stick for transferring files about, I'll give that a try tonight. Cheers!

USB works, I have transferred files about on it - but whether it works right/optimal is another matter. I didn't notice the speed last time.
 

andyinv

Member
Sep 14, 2015
32
0
0
@OP

I'm not familiar with Wirshark, but I do downloaded your files and open 2 of them.

fastlaptop.pcapng and slowtoserver.pcapng

I find that fastlaptop has much smaller TCP Window Size ranging from 250 to around 2000 yet slowtoserver has TCP Window Size = 64240, maybe this causes the slow down?

I hope experts in anand forum can help explaining.

Yeah, I'm noticing that - if you open them in Message Analyzer and enable the SMB2 view, you can see pretty spectacularly the time difference for the sections. It looks like SMB pipelining is happening, but the window size seems to be the big factor. Bytes-in-flight is quite a difference too..
 

andyinv

Member
Sep 14, 2015
32
0
0
So, finally grabbed a long enough gigabit cable from work and a quick iperf3 test:

Code:
[ ID] Interval           Transfer     Bandwidth
[  4]   0.00-10.00  sec  1.09 GBytes   939 Mbits/sec                  sender
[  4]   0.00-10.00  sec  1.09 GBytes   939 Mbits/sec                  receiver

Copied a test file over:
Code:
   Speed :            21131792 Bytes/sec.
   Speed :            1209.170 MegaBytes/min.

and copied it back:
Code:
   Speed :           102400000 Bytes/sec.
   Speed :            5859.375 MegaBytes/min.

Did various other tests copying the file over, and it's still considerably slower than receiving. But.... I can live with that. I'll end up routing this cable permanently I reckon.

So, onto the USB3 flash drive test.

First, laptop:
Code:
   Sequential Read (Q= 32,T= 1) :   205.606 MB/s
  Sequential Write (Q= 32,T= 1) :    57.143 MB/s
  Random Read 4KiB (Q= 32,T= 1) :     6.844 MB/s [  1670.9 IOPS]
 Random Write 4KiB (Q= 32,T= 1) :     0.729 MB/s [   178.0 IOPS]
         Sequential Read (T= 1) :   193.375 MB/s
        Sequential Write (T= 1) :    63.545 MB/s
   Random Read 4KiB (Q= 1,T= 1) :     5.517 MB/s [  1346.9 IOPS]
  Random Write 4KiB (Q= 1,T= 1) :     0.632 MB/s [   154.3 IOPS]

  Test : 1024 MiB [F: 54.9% (16.1/29.3 GiB)] (x5)  [Interval=5 sec]
  Date : 2015/09/18 18:57:22
    OS : Windows 10 Professional [10.0 Build 10240] (x64)

And now the troublesome Skylake desktop.

Code:
   Sequential Read (Q= 32,T= 1) :   172.811 MB/s
  Sequential Write (Q= 32,T= 1) :    30.590 MB/s
  Random Read 4KiB (Q= 32,T= 1) :     8.199 MB/s [  2001.7 IOPS]
 Random Write 4KiB (Q= 32,T= 1) :     0.879 MB/s [   214.6 IOPS]
         Sequential Read (T= 1) :   193.984 MB/s
        Sequential Write (T= 1) :    29.568 MB/s
   Random Read 4KiB (Q= 1,T= 1) :     7.100 MB/s [  1733.4 IOPS]
  Random Write 4KiB (Q= 1,T= 1) :     0.755 MB/s [   184.3 IOPS]

  Test : 100 MiB [D: 54.9% (16.1/29.3 GiB)] (x5)  [Interval=5 sec]
  Date : 2015/09/18 18:37:51
    OS : Windows 10 Professional [10.0 Build 10240] (x64)

It looks like despite the far higher spec PC, and the latest hardware, that in terms of writes my shiny new desktop is in the region of half as fast (reads, not so much different).

This would look very much like the chipset drivers for USB3 on Skylake motherboard aren't quite up to scratch yet and perhaps this is the reason my wi-fi sends (which might equate to disk writes in terms of data flowing out the USB) are so much slower.

I think we can close this one off as "it's all USBs fault"... whaddya think?