What are the "real life" speeds for Wireless N ?

I just purchased a wireless N router. My previous router was a Netgear
G router, and I did some test over wireless for transfer speed

Old Netgear G router
1.09 GB file - 650 seconds to transfer from my PC to my Mac = 13.7 Mb/
sec

New Linksys N router
1.09 GB file - 238 seconds to transfer from my PC to my Mac = 37.5 Mb/
sec

Wireless N is claimed to be up to 130Mb/sec. What is the real life
speeds? It seems like I should be getting more than just 37.5 Mb/sec.

On Fri, 16 May 2008 22:34:44 -0700 (PDT), cajunmonkey@gmail.com wrote:

>I just purchased a wireless N router.

Any particular maker and model Pre-802.11n Draft 2 router? There are
substantial differences between the spacial multiplexing and the beam
steering varieties.

>My previous router was a Netgear
>G router, and I did some test over wireless for transfer speed
>
>Old Netgear G router
>1.09 GB file - 650 seconds to transfer from my PC to my Mac = 13.7 Mb/
>sec

I get 13.4 Mbits/sec. Somewhat slow.

>New Linksys N router
>1.09 GB file - 238 seconds to transfer from my PC to my Mac = 37.5 Mb/
>sec

Not too horrible. The best you can do with 802.11g at 54Mbits/sec is
about 25 Mbits/sec thruput.

>Wireless N is claimed to be up to 130Mb/sec. What is the real life
>speeds? It seems like I should be getting more than just 37.5 Mb/sec.

There have been some benchmarks run by Tim Higgins:
"Cheap Draft 802.11n Router Roundup"
<http://www.smallnetbuilder.com/content/view/30387/96/> (7 page).
The performance numbers are a graph, where thruput is measured against
path loss (i.e. signal strength). At very low path loss, the MIMO
routers tested were able to do 50-70 mbits/sec in the 20MHz mode, and
60-70 mbits/sec in the 40MHz mode. Average thruput varied from 48 to
78Mbits/sec depending on model.

You can probably find your routers listed on the performance charts
at:
<http://www.smallnetbuilder.com/component/option,com_wireless/Itemid,200>
Looks like various wireless "N" routers go from 44 to 59 Mbit/sec.

If you plan to do some more benchmarking, I suggest you download and
use Iperf and Jperf:
<http://sourceforge.net/projects/iperf>
<http://sourceforge.net/projects/jperf>
Actually, you don't need to download iperf as the Jperf download
includes the Iperf binary. This tutorial explains how to use both
Iperf and Jperf:
<http://www.openmaniak.com/iperf.php>


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

<cajunmonkey@gmail.com> wrote in message
news:753a981d-af33-49f9-98eb-feeade8c3be5@z72g2000hsb.googlegroups.com...
>I just purchased a wireless N router. My previous router was a Netgear
> G router, and I did some test over wireless for transfer speed
>
> Old Netgear G router
> 1.09 GB file - 650 seconds to transfer from my PC to my Mac = 13.7 Mb/
> sec
>
> New Linksys N router
> 1.09 GB file - 238 seconds to transfer from my PC to my Mac = 37.5 Mb/
> sec
>
> Wireless N is claimed to be up to 130Mb/sec. What is the real life
> speeds? It seems like I should be getting more than just 37.5 Mb/sec.

Yah but-- this 1.09GB file is 8.72Gbit file at 0.130Gbit/sec =67 sec.
But
There is a lot of over head. At least packet conversions to use TCP/IP.
Error checking. FAT adjustments (I don't know what MAC's use maybe FAT 32)?
Drive speeds and buffer sizes. Things go on that we don't know about or have
any control over like interupts to do screen updates.
JPS
JPS