Wifi speed

[andreaf74]

Hi All,


I got my pandora about 1 month ago, and I've noticed that wi-fi speed doesn't exceed 1Mb/s which is awfully slow in my opinion.


With such a speed is nearly impossible to do most of the things I was hoping to do with such a device ( youtube streaming to name one)


I spent a few days (weeks) looking through the forum searching for a solution (driver updates, configuration...), but the only effective solution


so far seems to be buying an external USB wi-fi dongle(?!?).


I tried disabling encryption, power management, changing channel, but nothing seems to work, or at least with no noticeable differences.


Furthermore, there's not much debate on the forum about it as if this is not considered an issue at all(?).


Someone on this forum has suggested that this is an inherent limitation of the chipset for handheld devices category, which rise the


question : why bother with 802.11g support while it can barely reach the lowest of 802.11b speeds?


On the other hand comparable devices can get at least 10x the speed I got on pandora on the same medium (wireless), so I don't


think that there's a limitation in the chipset itself.


So, I would like to understand where's the issue (hardware/software), and if I can expect sooner or later a firmware update that address it.


Thank you,


Andrea

 

[WizardStan]

How did you measure the speed to know you're only getting 1Mb (I'm assuming you do mean 1Mbit, not 1MByte)?


Are you absolutely certain that you're only getting 1Mb? If you're just looking at the speed in ifconfig know that the speed is throttled to save power when not in use, so unless you were downloading something at the time it will only say 1Mb. You can turn off the throttling and make it full speed always with the command

sudo iwconfig wlan0 power off rate 54M

If you actually measured the speed and found you were getting 1Mb, however, while that is slower than some (mine gets 4.8Mb) it is still a little more than 2 times as fast as required for youtube streaming, so you shouldn't have any concerns about that specifically. It is strange that it would be going so slow and we can continue to debug the problem but it shouldn't be nearly as bad a situation as you make it out to be.

 

[WizardStan]

900KB/s is actually quite fast. Keep in mind that 802.11/g, while it has a theoretical throughput of 54Mbit, that doesn't include all the overhead that actually comes with network traffic. In real terms, 802.11/g under the best case scenario can transfer about 2MByte/s, maybe 2.5MB. For a cheap module with a tiny antenna, 4/11 of max is actually quite good.


To put into perspective, 900KB/s is fast enough to stream about fifteen 240p youtube videos simultaneously. Or buffer one video at 15 seconds per second, rather.


edit: scratch that, I apologize, I screwed up my numbers somewhere on the youtube thing. I thought something was wrong. Let me get back to you on this...


The rest of my numbers are more or less right though.

 

[WizardStan]

Scratch that scratch, I was right: a 1.5 minute 240p video is only 3MB in size, or about 35KB/s.


An inconsistent 300 is what I was getting before I got a new router. After the new router I got a consistent 600KB/s. I'm getting a second Pandora delivered to me soon, I'll see how that compares on both routers when it arrives, and I'll have a third one eventually for similar experimentation...


FOR SCIENCE!

 

[andreaf74]

Hi, first of all thank you for answering!

How did you measure the speed to know you're only getting 1Mb (I'm assuming you do mean 1Mbit, not 1MByte)?


Are you absolutely certain that you're only getting 1Mb? If you're just looking at the speed in ifconfig know that the speed is throttled to save power when not in use, so unless you were downloading something at the time it will only say 1Mb. You can turn off the throttling and make it full speed always with the command

sudo iwconfig wlan0 power off rate 54M

If you actually measured the speed and found you were getting 1Mb, however, while that is slower than some (mine gets 4.8Mb) it is still a little more than 2 times as fast as required for youtube streaming, so you shouldn't have any concerns about that specifically. It is strange that it would be going so slow and we can continue to debug the problem but it shouldn't be nearly as bad a situation as you make it out to be.

I measured the speed downloading some file from a local server, and yes I mean 1Mbit ( << 100kB/s ) and I'm talking about the actual speed not the "nominal" speed from the iwconfig command.


I've also monitored the interface state while downloading, and I saw that the "nominal" speed kept changing from 18Mb/s to 36Mb/s regardless of the actual speed I was getting (measured with wget).


I tried disabling the power management, fixing the speed, changing the channel on the router, changing the router ... without improvement...

from what i've seen, i wouldn't hold my breath for a better wifi support. A tiny usb wifi is the best choice.


with stock wifi, i can get speeds up to 900 kB/s


try another router

Why shouldn't I expect improvement on the wi-fi side?


Is it considered a non-issue?


Pandora is being sold as capable of 802.11b/g connectivity and it can't even reach 1Mb/s! This, in my opinion, is an issue (a serious one I would say), and should not come as a surprise if someone is expecting it to be fixed.


It feels like everybody gave up on this, as if it was a "fact of life" anyone should deal with... maybe buying an external interface.


Maybe there's a very good reason why the wi-fi interface can not be fixed , I just would like to know what this reason is.

900KB/s is actually quite fast. Keep in mind that 802.11/g, while it has a theoretical throughput of 54Mbit, that doesn't include all the overhead that actually comes with network traffic. In real terms, 802.11/g under the best case scenario can transfer about 2MByte/s, maybe 2.5MB. For a cheap module with a tiny antenna, 4/11 of max is actually quite good.


To put into perspective, 900KB/s is fast enough to stream about fifteen 240p youtube videos simultaneously. Or buffer one video at 15 seconds per second, rather.


edit: scratch that, I apologize, I screwed up my numbers somewhere on the youtube thing. I thought something was wrong. Let me get back to you on this...


The rest of my numbers are more or less right though.

I'm not asking for breathtaking speeds, I think 11Mb/s would be fairly enough for my needs, unfortunately my max speed is 50kB/s which is barely enough to do some Internet browsing...


Thank you.

 

[WizardStan]

Pandora is being sold as capable of 802.11b/g connectivity and it can't even reach 1Mb/s! This, in my opinion, is an issue (a serious one I would say), and should not come as a surprise if someone is expecting it to be fixed.


It feels like everybody gave up on this, as if it was a "fact of life" anyone should deal with... maybe buying an external interface.


Maybe there's a very good reason why the wi-fi interface can not be fixed , I just would like to know what this reason is.

The reason that it hasn't been fixed is because no one knows why it doesn't work for some people. As Alerino says, he tops out at 900KB. I have a stable 600KB. A lot of people have reported good speeds ranging from 400 to 900KB. And then someone comes along who barely gets 50KB for no obvious reason. It's frustrating.

I'm not asking for breathtaking speeds, I think 11Mb/s would be fairly enough for my needs, unfortunately my max speed is 50kB/s which is barely enough to do some Internet browsing...

And rightly asking you are, you deserve as reasonable a connection as the rest of us, I was just suggesting that while it is slow you could probably tone down the doomsday a bit: it's not fast, but at least it's connecting.


The only other test I can think of is dropped packets. Try this test:


sudo ping -f -c 5000 -s 1024 <router ip address>


That will flood ping your router and will give an indication of how many packets are being lost and what kind of speeds you can get. 1-5% is reasonable and would indicate your connection is stable, just slow. If you're seeing huge packet loss then it could be indicative of a connection quality problem.

 

[lunixbochs]

I just got my Pandora a couple of days ago. WiFi was hit and miss the first day... it connected to my WPA2 network very quickly, from a decent distance and through several walls/floors, but initially I couldn't even load pages in a web browser. Pings from a computer on the wired network would range from 40ms to 300ms / completely timing out (in bursts). At this point I was worried I'd received a broken wifi chip without the N module.


It seemed like the traffic was completely stopping at intervals for no real reason. Latency on a SSH connection into the Pandora was terrible - typing took several seconds and Putty was dropping some keystrokes. This happened while sitting idle at XFCE with nothing but a terminal open.


Weirdly enough, a ping *from* the Pandora to my router never dropped packets during that time and the roundtrip times stayed pretty low.


I boosted my router's wifi output by several times, and last night I was getting speeds up to 300KB/s or so over SCP. Compare this to as low as 10KB/s from earlier. Connections were snappier, completely usable over SSH, and pings maintained under 40ms when originating from both the Pandora and the PC. At times I did get much lower SCP speeds - 10-60KB/s - but I was able to do several high-traffic SSH connections running apps and GDB without the feeling my connection was being layered over carrier pigeon.


This is on a pretty high-end dual-band ABGN router on Tomato, with most of the devices on my spectrum running with N. . Maybe the Pandora was responding badly to external interference (though we have almost zero wifi overlap from neighbors). Perhaps it's a buggy wifi driver. I'll try it on a pure B/G router and play with distance from router and different wifi settings to see if I can find a reproducible+noticeable difference somewhere.


If I can't find an easy fix (and maybe either way) I'll probably play with the wifi kernel module after my current project... I'm definitely interested in working on this:

 

[andreaf74]

And rightly asking you are, you deserve as reasonable a connection as the rest of us, I was just suggesting that while it is slow you could probably tone down the doomsday a bit: it's not fast, but at least it's connecting.

I'm sorry if the tone of my post seamed a little harsh , I wasn't meant. Sometimes is difficult for non-native english speaker to choose the right words.


I was just trying to understand where the issue lies..

The only other test I can think of is dropped packets. Try this test:


sudo ping -f -c 5000 -s 1024 <router ip address>


That will flood ping your router and will give an indication of how many packets are being lost and what kind of speeds you can get. 1-5% is reasonable and would indicate your connection is stable, just slow. If you're seeing huge packet loss then it could be indicative of a connection quality problem.

I'll try the test you suggest as soon as I can, thanks!

 

[andreaf74]

I just got my Pandora a couple of days ago. WiFi was hit and miss the first day... it connected to my WPA2 network very quickly, from a decent distance and through several walls/floors, but initially I couldn't even load pages in a web browser. Pings from a computer on the wired network would range from 40ms to 300ms / completely timing out (in bursts). At this point I was worried I'd received a broken wifi chip without the N module.


It seemed like the traffic was completely stopping at intervals for no real reason. Latency on a SSH connection into the Pandora was terrible - typing took several seconds and Putty was dropping some keystrokes. This happened while sitting idle at XFCE with nothing but a terminal open.


Weirdly enough, a ping *from* the Pandora to my router never dropped packets during that time and the roundtrip times stayed pretty low.

Sounds familiar

I boosted my router's wifi output by several times, and last night I was getting speeds up to 300KB/s or so over SCP. Compare this to as low as 10KB/s from earlier. Connections were snappier, completely usable over SSH, and pings maintained under 40ms when originating from both the Pandora and the PC. At times I did get much lower SCP speeds - 10-60KB/s - but I was able to do several high-traffic SSH connections running apps and GDB without the feeling my connection was being layered over carrier pigeon.


This is on a pretty high-end dual-band ABGN router on Tomato, with most of the devices on my spectrum running with N. . Maybe the Pandora was responding badly to external interference (though we have almost zero wifi overlap from neighbors). Perhaps it's a buggy wifi driver. I'll try it on a pure B/G router and play with distance from router and different wifi settings to see if I can find a reproducible+noticeable difference somewhere.

I got the same feeling... I was able to get 200kB/s once, with no particular configuration, but it lasted only few minutes,My neighborhood is crowned with wi-fi AP so maybe it's really a problem of interferences... With this idea I tried all the available channels... unfortunately without luck: (

If I can't find an easy fix (and maybe either way) I'll probably play with the wifi kernel module after my current project... I'm definitely interested in working on this: http://boards.openpa...1692#entry51692

Thank you for the link, really interesting!, if you need help in testing let me know


Bye!

 

[WizardStan]

I'll try the test you suggest as soon as I can, thanks!

It could also mean your router has ping flood protection, it'll just stop responding if there are too many pings in a second, but it's a start.

 

[skeezix]

Note also that many phones and tabs only get say 500K/sec or so on wifi, and do fine. (Hell, my whole bandwidth is 600K/s and streams youtube HD 720p no problem.)


My Pandora can regularly pull 500K/s since HF5 or so (newer wifi drivers, always kudos to notaz) especially on power-hungry mode .. but things still feel sluggish or jittery at times; conclusion .. its more a function of response rate (not sustained bandwidth) and drivers (no flash driver, that sort.)


Do some wget's to pull down some raw files and see .. (though obviously it varies for your pandora and your router.) Set up a 100MB file on your laptop or NAS or something, and try sucking it down (for a pure wifi test, ignoring upstream.)


jeff

 

[EvilDragon]

WiFi depends on a lot of different things.


First, 802.11/g WiFi does NOT mean the WiFi device will always run fullspeed!


As skeezix mentioned, mobile devices usually run with lower speeds than desktop PCs, even though they both use 802.11/g.


This is to save power - otherwise, WiFi would drain a device pretty fast.


Quite a few mobile devices would be fine with 802.11/b, however, most routers can't do 802.11/b and 802.11/g at once. So if there's an 802.11/b device connected to that router, all other devices connected to the same router would also be slowed down by that.


Therefore, it's important these devices use 802.11/g.


Another thing one should not forget is SD Card speed as well as CPU power.


Depending on what you do, the Pandora might not have enough power left to USE that fast WiFi speed.


If you save a file to your SD Card and the card is very slow (or other programs are accessing the card as well), it will also slow down the transfer.


Of course, 50kB/sec still is too low. 400 - 600kB/sec should be possible with every Pandora.


Some users have problems, while it works fine with others. Often it helps to change the WiFi channel of the router.


About SSH: SSH is always laggish unless you turn off the powersaving feature.

 

[skeezix]

ssh does buffering as well; you can configure this in your .ssh config on the client side (or command line), but shouldn't generally be necessary.


I find ssh works _Great_ on pandora.. its one of the great features for me; ssh to my shell box, total win


jeff

 

[lunixbochs]

all my aforementioned tests were done over a period of many hours with wifi power saving disabled

 

[ivanovic]

Things depend mainly on the access points used. That is: At home I get a downspeed of maybe 120KB/s, sometimes dropping below 50KB/s, sometimes going up to 200KB/s (eg tested using wget and saving to /dev/null). When uploading (eg inside my home network using scp) I can easily get 600KB/s. At University I have also found some routers where I had a downspeed of significantly more than 500KB/s. So yeah, it all depends mainly on how well the router works together with the pandora and possibly how acks are handled, possibly a problem on both sides / the combination of drivers used.