# Bandwidth Speed Tests



## bobw (Jan 29, 2005)

Have a Mac that gets much lower results on Bandwidth speed tests.

Comcast Cable/ Netgear 814v2 Wireless Router. Both machines are wired to the router.

Mac
G4/450/AGP/1GHz Powerlogic Processor/1.25GB RAM/10.3.7

Speed Test results - 1860.5 Kbps

PC
HP Pavillion 6735/633Mhz/192 MB RAM/WindowsXP

Speed Test results - 3258.8 Kbps

Any way to get the Mac up to the spped the PC gets?


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## andychrist (Jan 29, 2005)

Gee Bob, I was just going to ask _you_ for help on that one.   

I kinda wonder how accurate those speed tests are, because I get different results from some sites on on my iForced BondiMac depending on which browser I am using. For instance, http://www.beelinebandwidthtest.com/ takes a while to complete a test for me in Safari, but usually gives my connection a decent score.  Using Firefox, the test completes in like a split second, but beeline records an abysmal score.  

I am accessing a Road Runner cable through a wireless network, so local traffic really affects my dl speeds, but testing with http://www.testmy.net/ or http://nyc.speakeasy.net/ gives me results between almost 3 MB/s down to like, well, almost nothing.

Also tests that display the download graphically in real time, such as http://www.giganews.com/comps/test_connect.mhtml and http://www.aroundcinci.com/speedtest/ will start out super fast, then trickle way down to ISDN speeds on any browser for me. But my downstairs neighbor's SnowMac displays a consistently high speed on the same tests, using Verizon's new 3 MB/s DSL service.

Guess the proof of the pudding is in the eating - the most accurate speed test is still just how fast pages actually load.


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## bobw (Jan 29, 2005)

Try this speed test, it gives a lot of info;

http://jlab4.jlab.org:7123/

Haven't figured it out yet.


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## andychrist (Jan 29, 2005)

Thanks, I was looking for a new verbose test.

This connection is receiver limited 88.05% of the time.
  Increasing the current receive buffer (63.0 KB) will improve performance
This connection is network limited 11.78% of the time.

So who is the receiver: the modem, router, or Mac, and how can one increase the receive buffer? 

I'm not really too concerned about current performance, as I am getting reports from over 2 MB/s down to about 1 1/2 MB/s on my shared network connection, and I have already signed up for that new Verizon DSL service.  What I am wondering is if there is any setting on my iMac that is causing it to drag as downloads progress, or is that a just a peculiarity of cable.  (Even in a new User account I get that same slowing-down behavior.)  Fortunately Verizon includes a one month free trial so I can see if there's any difference.


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## bobw (Jan 29, 2005)

Don't have any answers, still trying to firgure it out. My PC, using the same router, gets double the speed.


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## arkayn (Jan 29, 2005)

Why do they all want to use Flash, that is probably one of the slowest interface elements on the mac.


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## arkayn (Jan 29, 2005)

dslreports says that in Firefox I have 209 down and 150 up while Safari says I have 210 down and 200 up.


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## TommyWillB (Jan 29, 2005)

arkayn said:
			
		

> Why do they all want to use Flash, that is probably one of the slowest interface elements on the mac.


The one bobw pointed us to is a Java Applet, not Flash...

Do Safari and Firefox use the same Jave virtual machine?


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## scruffy (Jan 29, 2005)

I just tried the test you pointed out bobw.  It said

...
running 10s outbound test (client to server) . . . . . 560.97Kb/s
running 10s inbound test (server to client) . . . . . . 1.23Mb/s
...
This connection is receiver limited 87.19% of the time.
  Increasing the current receive buffer (63.0 KB) will improve performance
This connection is network limited 12.63% of the time.
...

increased the send and receive buffers (which it miscalculated, apparently) from 32K to 64K, and got very nearly the same results:

...
running 10s outbound test (client to server) . . . . . 561.19Kb/s
running 10s inbound test (server to client) . . . . . . 1.23Mb/s
...

Then I increased both buffers to 128K, and got:

...
running 10s outbound test (client to server) . . . . . 612.91Kb/s
running 10s inbound test (server to client) . . . . . . 1.24Mb/s
...
This connection is network limited 99.83% of the time.
...

So, apparently the OS was low-balling my upload speed, but not so much my download speed; but still a bit of a difference.

Anyway, you might want to play around with the tcp related sysctl variables.

to see what they are now

sysctl net.inet.tcp

I set the buffers like so:
sudo sysctl -w net.inet.tcp.sendspace=131072
sudo sysctl -w net.inet.tcp.recvspace=131072

to get the very slightly increased performance I saw.


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## bobw (Jan 30, 2005)

Ok, removed Broadband Optimizer. Went back to original settings for;

 sudo sysctl -w net.inet.tcp.sendspace=32768
 sudo sysctl -w net.inet.tcp.recvspace=32768
sudo sysctl -w net.inet.udp.recvspace=42080

Now I'm getting the same speed as the PC;
=====================================
http://www.testmy.net/results_d.php

Your connection is:       3518  Kbps      (about 3.5 Mbps)
You downloaded at:     429 KB/s
=====================================
http://www.dslreports.com/speedtest...4a9e79e63635;2.0;nyc.speakeasy.net/1107097113

Yours «3487 down
        «344 up
=====================================
http://www.giganews.com/test_connect.html

Realtime Results
connectin speed - 4107 kbps
=====================================
http://www.aroundcinci.com/speedtest/

Speed - 3,483 Mbps


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## Decado (Jan 30, 2005)

What does all this mean? 
i have a broadband connection at my home that is 24 mbit/s (but since i am connected through wi-fi some is lost and it is more like 19mbit (but i am not complaining, i know people who have worse).
i too ran the test at JLab and it said:

bw = 32.35 based on packet size = 10Kbits, RTT = 322.62msec, and loss = 1.0E-6
The theoretical network limit is 32.35 Mbps
The transmit buffer (125.0 KByte) limits the application to 3.02 Mbps
Your receive buffer (63.0 KByte) limits the application to 1.54 Mbps
The network based flow control limits the application to 1.55 Mbps

could somebody with brains please explain what it mean.


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