Wireless LAN speeds with Intel 3945ABG. Why so slow?

[ramian]

Comparing wireless LAN speeds between my T60 with an Intel3945ABG card and my T30 with a Linksys WPC54G PCMCIA card, the T30 is almost always able to hit at least 1Mbps and can peak at 2Mbps while the T60 is unable to hit 1Mbps and generally averages at 500-700kbps. Both connect wirelessly to a WRT54G (v2.2).

Speeds were determined using Bandwidth Monitor Pro based on upload/download rates between the Thinkpads and my main PC connected via wire to the Linksys router. I run a local FTP server on my PC (using Filezilla server) so that all clients in my network can access files on the main PC via FTP (Filezilla client). I prefer this to using shared folders as I can allow multiple FTP connections to help speed things up when I'm transferring lots of files.

The only other (seemingly important) difference between the 2 Thinkpads other than their wireless network cards is that the T30 is running XP Pro SP1a while the T60 XP Pro SP2. While SP2 is limited by the number of half open connections, I don't believe this to be the reason why I'm getting slower LAN speeds. Patching tcpip.sys using the EvilD patch doesn't help. Also, the T30 uses the Linksys software to connect to the network while the T60 uses AccessConnections. I also don't see this speed difference when I connect the Thinkpads with wires; I get close to the 10Mbps promised (6-8Mbps).

Other than pointing an accusing finger at the Intel3945ABG, I can't imagine what else could be causing this difference in wireless LAN speeds.

What kind of wireless LAN speeds do you guys get with the 3945ABG? Is there anyway I can speed up wireless LAN speeds on a 6-month old T60 so that it can at least keep up with a 5 yr old T30 with a PCMCIA wireless adpater?

Thanks!

[Scratch]

Is the Linksys setup a speed booster card with the matching speed booster AP?

Silly question, but what is the relative signal strength on the 2 card types when reaching peak speeds?

Both are obviously G cards forced to G only?

The Intel card has been stripped down to the bare essentials to run via MSconfig?

[ramian]

Greetings and Happy New Year to all!
I'm finally back in "civilization" after having spent nearly a couple of weeks in the hills with no internet access.

@Scratch, in response to your questions...

Neither the PCMCIA card nor the router has speed booster. They are just the standard ABG versions.

How do I determine relative signal strength? Is it based on the %? If so, I seriously doubt this to be the issue as when I'm right next to the router (both cards showing 100% signal strength), I'm still getting consistently slower speeds on my T60 with the Intel 3945ABG.

Both are ABG cards but they are set on Auto. However, I have never seen the connection speeds change from 54Mbps, so shouldn't that mean both the cards automatically set themselves to 802.11g instead of the slower a or b?

While I have played around with startup options, I have not touched any thing to do with Intel software or the wireless card.

Any other help would be appreciated.

cheers!

Update: Just found out that I can hit internet download speeds of more than 1Mbps from Microsoft (that's mega bytes per sec), which is somewhat of a new record for almost anyone here in Singapore, but I'm still barely hitting 700kbps for internal LAN transfers. Apparently, my 6.5MBps cable connection got upgraded to a 12MBps one (without any improvement in the crappy 384kBps upload ), which kinda explains the nice download speeds. Why my wireless connection is still slow for internal LAN transfers is still up in the air. I've updated to the latest driver versions from the Lenovo site (Software Installer doesn't find updates for me anymore and I haven't installed System Updater yet); I'm using wireless drivers 10.5.1.0 and ethernet drivers 9.2.50.10.

Edit2: Would enabling packet bursting and forcing a 802.11g connection allow the Intel card to transfer at the maximum possible speeds? I presume that in theory, as the signal strength decreases as distance from the access point increases, the card automatically switches to a less stringent (?) connection like the 802.11b, thus causing slowdowns in LAN traffic. Perhaps something might be wonky with my wireless card which prevents it from clocking back to 802.11g even when signal strength is good... This is ofcourse all hypothetical; I only have very basic knowledge of wireless networks and so don't know if this is the problem or not. I will definitely try out enabling packet bursting and forcing a G connection (instead of leaving it on auto) to see if I get any improvements.

Any other comments to make sense of my warped sense of thinking would be appreciated.

[bigbear2007]

I gave up and purchased a cardbus dlink wireless lan card and never looked back.

[pinesol]

I may not have a right answer for you, but in my experience the router can make a big differece, especially for using web browsers. I suppose the LAN card can also make difference.

I don't have any experience with the Intel card, but I was advised to get Aheros card instead of Intel before I bought my T60. They told me the Intel card was no good.

[ramian]

Thanks for all your replies.

The "standard" method of uninstalling and re-installing drivers and access connections kinda worked for me. Now, when I'm physically next to the router, I get up to 2.5Mbps, which is as expected. However, when I'm in my bedroom with about 20% signal strength, speeds are as slow as they used to be. The reduction in signal strength doesn't change the connection type (a/b/g), which might account for reduction in wireless speeds, but rather reduces throughput. What doesn't make sense though is that when signal strength is low, I can still download from the net and speeds > 1Mbps but not have internal LAN transfers even near that speed.

Is there anyway of "cheating" the network card into maintaining network throughput even at low signal strengths? I understand why throughput it reduced at low signal strengths, but since my notebook isn't really moving anywhere, and the wireless signal from my router is consistently strong (or weak in my room), there shouldn't be any need to reduce throughput just to safegaurd against dropped or delayed packets right? I'd like to find out if there is any way of forcing the throughput to remain at maximum even when signal strengths are low.

I know an alternative would be to increase transmission power from my router so that I could get higher signal strengths even in my bedroom. For my current router (WRT54G v2.2), I understand that there are various 3rd-party firmware available which will increase transmission power beyond the 15dBm. Has anyone had any success with improving signal strength by increasing transmission power of their routers?

I will be getting a new router (the new D-Link DGL4300) in the hopes of solving the problem of the WRT54G not being very stable when using P2P apps. I'm hoping this new router would also have improved transmission capabilities to solve the signal strength problem of mine. My last choice would probably be to get the Atheros card to replace the Intel one. Other than from IBM itself, does anyone know where else I can get the Atheros card for cheaper?

cheers!

[Scratch]

How about changing out to high gain antennae on the access point?

Maybe putting a 2nd AP in your bedroom to act as a repeater? AP's are pretty inexpensive these days.

[GomJabbar]

Another user reported success using this solution recently.

PSP (Power Save Polling) Causes Connection Issues With Some Access Points

[TwoSteppin4140]

Another user reported success using this solution recently.

PSP (Power Save Polling) Causes Connection Issues With Some Access Points

Heh...I was just gonna pop in and post that. But, what I did was to go into access connections and adjusted the power settings to yield the best performance (read: less battery) ... seemed to work.

And, thanks again, Gom.

[ramian]

Thanks for your replies.

Unfortunately, I'd already set it to maximum performance.

@Scratch,
Using another router as a repeater sounds like a good idea. I suppose I could try that out with my WRT54G when I get the new D-Link.

In the mean time, if there's nothing else I can do on my Thinkpad to help improve network speeds, I suppose I'll have to wait it out.

Thanks guys.

cheers!

[ALENOVOTECH]

for me I think is has t do with Access Points.

At work I use Dell branded AP B/G router. Just cheep one you buy for home use. Can not remember the model.

At home I use Dlink DGL-4300 Wireless 108G Gaming Router.

At work I am almost 200 Feet away in room with no walls(work in a warehouse I have no problems. The single is only about 43% no drops. When I get next to it I get 100%

At home I can be in the same room as the AP and only get 60% max. Constant drops and re-connects.

There my 2cents

Thinkpad T60p With Intel3945ABG Windows Vista AC 4.31 Intel Driver 10.6.0.15