Posted: Fri Jan 05, 2007 8:36 Post subject: low throughput..what gives?
Hello everyone, i am running the latest build of dd-wrt 12-21-06 on a WRAP board with an atheros minipci card, which is in turn connected to a 1 watt amplifier with AGC, going into a 12dB omni. Performing speed tests over samba from a laptop with built-in intel pro/wireless 3945abg card, as well as a proxim silver g card from about 10 feet away line of site, with a netstumbler reported signal level of -34 and noise of -100 the max throughput i have been able to generate transferring from a gigabit lan client is 2000KB/s for a brief moment and averaging around 1800KB/s over 11g. This is with WPA enabled. I have tried disabling ACK and it makes no difference, the speeds stay the same. I have tried channels 1,6, and 11 and the throughput stays the same, i have adjust the TX output of the card going into the amp from 10mW-100mW and it makes no difference. Is there anyone else running a wrap board that could tell me what kind of throughput they are getting and what settings i should try altering? Thanks!
Joined: 06 Jun 2006 Posts: 7492 Location: Dresden, Germany
Posted: Fri Jan 05, 2007 11:23 Post subject:
you can expect about 3600 kbyte/s in 802.11g. this was my maximum throughput _________________ "So you tried to use the computer and it started smoking? Sounds like a Mac to me.." - Louis Rossmann https://www.youtube.com/watch?v=eL_5YDRWqGE&t=60s
Thanks for the replies. Why would removing the amp increase throughput? I am using a high quality amp and a friend of mine with a similar amp has no problems with throughput like i do?
The easiest way to explain this is with a simple analogy.
How well would you be able to understand someone shouting down a megaphone on full volume standing 10 feet from you.
This is effectively what you are doing with the amp in your system. If you are planning to setup a long link (greater than 10kms) than an amp might be required. For home installations there is no need at all. I have a number of long links running using DD-WRT's and have never had to turn the units power output up above 40 mW. The longest of these links is 7km's and I get 1200 kbyte/s on this link.
The rule to use when setting up any wifi link is to keep the power output of the radios as low as possible. If you do need to use an amp for long links then to make it work properly you will need one at each end of the link.
Hope this helps you understand the problem a bit more.
Joined: 06 Jun 2006 Posts: 7492 Location: Dresden, Germany
Posted: Sat Jan 06, 2007 19:27 Post subject:
yes it is. i would explain it in the same way _________________ "So you tried to use the computer and it started smoking? Sounds like a Mac to me.." - Louis Rossmann https://www.youtube.com/watch?v=eL_5YDRWqGE&t=60s
I have to own up and say that it isn't mine. I'm sure I saw it, or a similar analogy on this forum or another one I regularly use for router/wifi stuff.
At the time it impressed me as a good way of explaining the problem.
Thank you all for the information. You where indeed correct, the amp does seem to be the culprit and it does make sense because when i unplugged the power speeds jumped to about 3100kB/s. Unfortunately i have such a large and dense area to cover the amp is going to stay and i'll just have to lose that extra MB/s of speed. Hopefully 11n mini-pci cards will be out soon and solve the speed problem anyways
