Can my MacBook use 40MHz bandwidth?

[thiggins]

I can't find a definitive answer about this and don't have any Apple clients to test. But my guess is that Apple also locks out 40 MHz bandwidth in the 2.4 GHz band in their N clients, also.

 

[zjohnr]

Look again before you leap, perhaps?

I guess my point... or question is... does Apple prevent an Apple card from connecting to a 3rd Party router at 2.4Ghz/40Mhz? Because if so then owners of Apple cards would need a router (Apple or Other) that runs at 5Ghz to take advantage of 40Mhz bandwidth....

I would view it more as "does not provide support for" rather than "prevents". But maybe I'm just quibbling.

I'd also urge some reflection on the environment you intend to use 5 GHz in before you jump to it. If you don't have many barriers (walls, floors, furniture, et cetera) for the signal to pass through and the distances you want to span are not "too far" then maybe you'll be happier with 5GHz.

But at least take another look at the reviews of the routers you think you are interested in to see how they perform in the 5 GHz band. I'm not sure what benefit you are hoping to get from the 40 MHz bandwidth, but it may not be as useful or usable for you as it seems in theory.

In other words, caveat emptor.

-irrational john

 

[prestain]

I just wanted to let you know that you can hold option and click on the wifi menu. This will show you more detailed information about your connection. Registered just to share this little tidbit cause I found it so useful when I first found out about it.

 

[thiggins]

I just wanted to let you know that you can hold option and click on the wifi menu. This will show you more detailed information about your connection. Registered just to share this little tidbit cause I found it so useful when I first found out about it.

Thanks for taking the time to post this info.

 

[Aluminum]

AppleBSD

I would view it more as "does not provide support for" rather than "prevents". But maybe I'm just quibbling.

I'd also urge some reflection on the environment you intend to use 5 GHz in before you jump to it. If you don't have many barriers (walls, floors, furniture, et cetera) for the signal to pass through and the distances you want to span are not "too far" then maybe you'll be happier with 5GHz.

But at least take another look at the reviews of the routers you think you are interested in to see how they perform in the 5 GHz band. I'm not sure what benefit you are hoping to get from the 40 MHz bandwidth, but it may not be as useful or usable for you as it seems in theory.

In other words, caveat emptor.

-irrational john

Considering that the hardware, firmware and original oem developed for it, prevents is correct.

Apple has used various chipsets, but with the (for example) atheros 5008-3nx chipset found in some airport cards, 40mhz on any band is clearly supported by the hardware and other OSes, including multiple *nix variants of which OSX is.

The support is there, it is deliberately removed, disabled or prevented if you need more proper synonyms I wouldn't be surprised if it is basically just commented out in the source.

Sure, 40mhz is not always a good idea, but if you are out in the boonies and have your AP just to send wifi across a nice open room, why shouldn't you have the choice to enable it?

 

[zjohnr]

Grumble, grumble, grumble ...

Sure, 40mhz is not always a good idea, but if you are out in the boonies and have your AP just to send wifi across a nice open room, why shouldn't you have the choice to enable it?

Well, that's pretty close to my situation. There are other APs around, but they are in other buildings all at least 75' or more away from mine.

If the wireless hardware in my MacBook can support 40MHz, then at least that holds open the (admittedly very slim) possibility that "patching" the software in some way might enable it.

Oh, well. I wonder what would happen if I booted up Windows 7 on my MacBook. Would 40MHz work there or would Apple have taken the trouble to also disable anything except 20MHz bandwidth in their Windows wireless driver?

All this just because Apple thought that 40MHz in the 2.4GHz band might maybe possibly conflict with Bluetooth? Hey, I've got Bluetooth turned OFF! Can't the software take a hint?

-irrational john

 

[zjohnr]

An update on Mac Airport 2.4 GHz client link rates

You need to look at the client's (the MacBook) link rate, not the router.

I would if I knew how to do this. But I have not been able to figure out how to display the link rate in OS X 10.5 on my MacBook.

http://discussions.apple.com/thread.jspa?messageID=6623194

A brief update about ways to learn the client link rate in a Mac in addition to the link Tim provided (quoted above).

First, as pointed out in one of the posts in this thread, in Snow Leopard, OS X 10.6, information about the client link rate (and lots of other stuff) can now be found in the Airport section of the system profiler.

It also possible to display this information by pressing the "Alt" (aka "Option") key and (left) clicking on the Airport icon in OS X menu bar located on the right hand side of the top of the OS X screen.

Second, I finally got around to testing 40 MHz bandwidth on my DIR-655 with an (admittedly old) Netgear WN111v2 USB adapter client. While it of course fluctuates, the WN111v2 does often show a link rate of 300Mbps. So the 130 Mbps limit on my (early 2008 white) MacBook seems to be pretty definitely a limitation of the MacBook, not of my router.

Third, as Tim has and continues to point out, 40 MHz bandwidth and 300 Mbps link rate does not seem to buy me much. The throughput in terms of MB/s as measured by Windows 7 LAN file transfers does not seem to be more than 1 or 2 MB/s faster than what I get with just 20MHz bandwidth. (At most. Often enough the throughput appears to be about the same or less than what my MacBook client experiences).

This is under excellent signal strength conditions with the adapter maybe 10 to 12 feet away from the router. The router is on a top shelf a tad over 6 feet above the floor in the same room. No walls or other obstructions.

This begs the question, if I get basically the same throughput at 130 Mbps link rate as at 300 Mbps, what the heck happened with that "extra" 170 Mbps of raw link rate? Stolen by the wireless throughput gremlins?

Apparently 40 MHz bandwidth is one of those "Why did they even bother?" features. It looks good on paper but I can't seem to get anything much of a practical benefit out of it.

But maybe that's just me ...

-irrational john