Hello everyone,

I have a odd problem. I have twin girls and they both have the same laptop, a Toshiba L755. They both have Ubuntu 11.10 on it. One computer have no problem with the Internet speed on Wifi and the other have...

The network controllers are the same: Realtek 8188CE

When I check the Internet speed on the same website after booting, it's quite comparable (9 to 18 Mb/s) but still better on one of them. But if i do the test again without booting, on the first one it's still ok, but on the other one it's anemic....(750kb/s). I have to reboot to have a fair result again.

I don't have a clue of what can be the problems:

1. What it'is different on the same model of computer with the same OS

2. Why the wifi speed is fair right after booting and anemic if I try again.

Thanks for your advices,

Well, there are several possibilities:

First, are you testing them from the same physical location? Walls tend to destroy WiFi signals, so if there's more walls in the way of one computer, you could definitely see some slow-downs.

Second, are both OSes exactly the same? Same drivers, same updates, same everything? If the speed seems to drop off after boot, you might want to check to see if there's any software that's doing funky things on the network.

Third, you may consider running a boot disk on them and trying a speed test from there. If the results are the same in the boot disk (i.e. slow on one, fast on the other), then you may have hardware issues. If you're the DIY type, you may want to open it up and check on the card seating and antenna condition. The antenna is more often than not just a wire that runs up through the lid hinge into the bezel. A lot of flexing occurs there, which could (though I've never seen it) damage the antenna. If you're feeling really adventurous, try swapping the WiFi cards between the two laptops.

If opening computers rubs you the wrong way, you could also call Toshiba up and ask them. If it's still under warranty, they may replace it for you.

thanks for the answer,

I was testing them from the same location and with the same OS updates. By boot disk, you mean a live CD?

This morning, I did another test and the download is slower than the uploads... (678kb/s vs 3Mb/s)

Yes, I was referring to a live CD or live thumb drive. When troubleshooting, the idea is to remove as many variables as possible. That's why I suggested that you test them from the same physical location with the same boot disk. Test one variable at a time, that way you're more likely to fine the real problem.

I booted both laptop with a Ubuntu 11.10 USB key at the same time and in the same location. And the result is confirming that one computer has problem with the wifi card. The download speed was 700Kb/s on the faulty one and 30 Mb/s on the other one. So it's suggest that's a hardware problem.

It's the first time I have this problem. My warranty still available, so I will have to reinstall Windows (I don't have to argue about ''the problem is from Linux'' or ''the warranty is no good anymore because you put Linux on it''...) and call Toshiba.

Thanks for your help.

If I were you, I would take the hard drive out of the computer and send it back to them. Tell them what the issue is and ask for a replacement. If they tell you "it's Linux's fault" or "Linux voids the warranty" (which it doesn't), demand to talk to a supervisor. I've never dealt with Toshiba's tech support personally, but I have heard that they're at least partly competent. (I'm still scarred by my experiences with Dell support. Never again!).

I put back Windows on the laptop and the problem is the same. I'm gone contact Toshiba to fix the problem. I don't want to ''play'' with the hardware of the laptop and risk to void the warranty.

Alright. Best of luck to you.

Update...

1. First test: I put both laptops near my router and the performance was equal on both computer (Windows 7 64 newly reinstalled on the problematic laptop and the other one with Ubuntu 11.10 32), but as soon as I put an obstacle (walls) the problem went back. So I tought, the problem is the same on Windows, so it sure be a hardware problem, maybe the Antenna?

2. Just in case I tried to update the latest driver for the Realtek wifi card on the ''new'' Windows 7 64 laptop and ''voilà'' the Internet connection went wild...

I tried to install the latest linux driver before I changed OS from Ubuntu to Windows and it didn't change anything (in the readme files they were saying that the driver was compatible with Fedora, Debian...but no mention of Ubuntu, I choosed the Debian, but is it ok?)

So it's really seem a driver problem. But how could I have a problem on one laptop and not the other if the laptops are at first identicals and have the same OS with the same updates? anything to do with an erratic driver performance on Ubuntu's 32 version vs Windows's 64?

I don't have a clue... I'm in the twilight zone...do do do do do do do do ...

I'm usually hesitant to use the driver that realtek provides unless it's the only option. In my experience, the community drivers are usually better tuned and tested, especially if they came from the official repos.

In the 32 vs. 64 bit realm, I would be very surprised if the 64 bit drivers are more stable than the 32 bit ones.

But with all this, your mileage may vary.

(By the way, I'm assuming by "went wild," you mean "started working well." Am I right?)

By community you mean Ubuntu? Is there a way to find the newest one? And yes wild mean working well.

https://help.ubuntu.com/community/Ha...rdsRealTek#PCI

It's always good to check the wikis for hardware and driver info. And yes, I was referring to the community of developers that work on the Ubuntu software repos. Pretty much everything in the apt system is checked over by many community members before it ships.

Thanks for the tip ! I'm going to check that.