Airport Express N + Time Capsule throughput issue

[krsnet]

Thought I'd try both semi-questionable devices at the same time... Couldn't find similar question in the forum.

Setup is:

All wireless on suspect network are N only (secondary b/g running from Linksys wrt54g). All software/firmware up to date (7.3.1 AX and TC).

WIRED
CableModem
|
Time Capsule (5Ghz, N only) - iMac G5
|
wrt54g (2.4Ghz, b/g)

WIRELESS
Airport Express N (extend TC N network) -> MacBook & AppleTV

Without the Express-N, I had poor reported connections to the MacBook & AppleTV (80-117 Mb/s with matching actual throughput). With MacBook in same room as the TC, I had a good 270 Mb/s with throughput matching the reported connection speed.

Added the Express-N and had solid 270 or 300 Mbps connections between all wireless devices (TC <-300-> AX <-270-> both MacBook and tv). Signals look good and reported speeds look great, however, actual throughput was only around 2MB/s (~16Mb/s).

Only test I haven't tried yet is removing the wrt54g so there's no 2.4GHz b/g network (though I can occasionally see the neighbor's network).

Using Airport Utility 5.3.1 "Wireless Clients" for signal chart. Using iStat for actual throughput (appears to match calculated throughput using known file size and time). iStumbler, and APGrapher appear to match data from Airport Utility (though they get confused with the "extend network" feature).

Any ideas on why such good reported connections result in such poor actual throughput?

Adding/removing devices yields consistent results so the problem appears to be directly tied to the Airport Express extending the network.

For full disclosure: http://discussions.apple.com/thread.jspa?threadID=1445384

[getmilton]

Thought I'd try both semi-questionable devices at the same time... Couldn't find similar question in the forum.

Setup is:

All wireless on suspect network are N only (secondary b/g running from Linksys wrt54g). All software/firmware up to date (7.3.1 AX and TC).

WIRED
CableModem
|
Time Capsule (5Ghz, N only) - iMac G5
|
wrt54g (2.4Ghz, b/g)

WIRELESS
Airport Express N (extend TC N network) -> MacBook & AppleTV


Hi,
i plan on getting the airport express N to make this same setup. only instead of the wrt54g i have an old airport express G. i would love to hear how this works out for you, since it's almost identical to what i want to do.

do you have all the stations on one floor? (i have a two floor area i'm trying to cover)
i heard you're supposed to get a 50% degradation in throughput with every "hop" from the macbook back to the TC. you said you were getting 270. is that in the same room as the TC, or are you clearly in the range of the airport express?

thanks for the post!

[krsnet]

Just to close out...

Went to the "Genius Bar" and they gave me a new TC. All is good with the world now. Had to settle on 2.4GHz due to the structure of the walls in my house so I max out at 130Mbps, but that's far better than I was getting.