5GHz no faster than 2.4 with the AEBS??????

~J~

macrumors 6502
Original poster
Jul 27, 2007
447
0
3rd Rock from the sun
I get a VERY steady 1.06MB/sec transfer rate when in 2.4GHz -n w/ -g compatability mode (130Mb/sec connection between MBP & AEBS)... I get ~1.10MB/sec transfer rate when in 5GHz mode )300Mb/sec connection from MBP to AEBS)... my question is... why such a minimal increase?? Both should be connecting a LOT faster than what they are... why is this?? I have a direct line of sight and about 3ft distance when in my office and about 20ft distance when in my living room. I dont get it. I should see closer to 16.25 MB/sec when in 2.4 mode & 37.5 when in 5GHz mode!! Any ideas on how to speed things up??
 

~J~

macrumors 6502
Original poster
Jul 27, 2007
447
0
3rd Rock from the sun
You really should see bigger numbers. I assume your AEBS firmware is up-to-date.
Yes sir. All firmware & software updates are installed as soon as they come out. I've even reset the AEBS and rebuilt my network from scratch... same result. This is definitely not how an -n network should be running and its really frustrating as I do large file transfers (1-6GB) to the wireless disk almost on a daily basis right now...
 

~J~

macrumors 6502
Original poster
Jul 27, 2007
447
0
3rd Rock from the sun
Ok... this is officially driving me crazy. Just for kicks and giggles, I started a large file transfer (1.5GB) from an old PowerBook G4 (15" 1.5GHz) which is connected to the -g side of my network... it is transferring at 1.67MB/sec!!! Yeah, its only slightly faster than my MBP connected at 5GHz/300Mb... but its out-performing a MUCH more powerful system!!!! HOW???!!!
 

macleod199

macrumors 6502
Mar 10, 2007
274
0
Another MBP and/or a HD connected to the AEBS via USB2... which should be 480Mb/sec (I know, I know... its all theoretical... but I see ~300Mb/sec w/USB all the time...)


So what gives??
The low-speed processor in the router has to translate from the network file protocol (encapsulated in ethernet frames) into whatever the disk's format is, encapsulated in USB frames (which are notoriously processing intensive). If you look around the forum those are relatively normal rates to the USB disk on the Airport... it's not exactly server-class hardware in there. It's possible that the transfer was slightly faster from the older hardware because it was having to do less work to decode the older, simpler wireless format, leaving more processing power to encode to USB.

Also be sure not to get your megabits and megabytes confused. Megabytes are at least 8 times bigger than megabits (8.4 times in the worst case.. if you consider a kilobyte to be 1024 bytes and a megabyte to be 1024 kilobytes).
 

bplein

macrumors 6502a
Jul 21, 2007
518
187
Austin, TX USA
Another MBP and/or a HD connected to the AEBS via USB2... which should be 480Mb/sec (I know, I know... its all theoretical... but I see ~300Mb/sec w/USB all the time...)


So what gives??

You see 300Mbit (37.5MB/s) on USB2? With what? The best I can get consistently with USB2 drives is about 24MB/s. 480Mbit signal rate does not equal 480Mbit transfer rate.

With respect to AEBS, I was getting 4-7MB/s last night when writing to and reading from a USB drive connected to the AEBS, and more when reading from my file server in the garage. I got a little bit better speed when using 5GHz vs 2.4. And got better speeds when using higher multicast rate (but at the expense of reduced range). My AEBS is upstairs across the house, not 3 feet away. You should be seeing better numbers.

The big deal is what are you testing with and connecting to in order to get those measurements?
 

bplein

macrumors 6502a
Jul 21, 2007
518
187
Austin, TX USA
One other thing: DO you have the newer Gigabit Ethernet model, or the older Wireless-N with 10/100 Ethernet? If the latter, you have a 100Mbit bottleneck, and with a single file transfer you can expect to get about 6-8 MB/s (50+% efficiency of the full 100Mbit link).

(edited later)

Sorry, you are using a USB drive. Never mind.
 

bplein

macrumors 6502a
Jul 21, 2007
518
187
Austin, TX USA
I have to correct my earlier statement. With ~reads~ from my external USB drive, I am seeing about 32MB/s for large file transfers.