need advice on improving wireless throughput

[ginahoy]

Hi. I'm new to the forum, and could use some help. This thread grabbed my attention as I've been spending considerable effort troubleshooting slow wireless throughput on my T42 (Win XP). Wireless is consistently below half of Ethernet speed. The laptop always shows "excellent" connection (5 bars).

I just replaced the OEM wireless adapter (Philips 91P7301) with an Intel Pro 2200bg. Unfortunately, it made little difference. I use several benchmarking ftp sites that give consistent results. Except for the private ftp server, which is hard-throttled at about 275KB/s, the Ethernet speeds are constrained by my DSL connection.

Code: Select all

FILE SOURCE       802.11g     Ethernet (KB/s)
speedtest           240           560
filefront           255           575
private ftp sever    77           270 

Before switching cards, I tried the following
* upgraded firmware (wireless adapter and WRT54GL router)
* temporarily disabled security/encryption
* changed mode from 'mixed b/g' to 'g only'
* tried different channels
* tried another router (my DSL modem has integrated wireless)

None of these individually or collectively made a hair's difference, perhaps 5% at best. Advice would be appreciated.

[jrumohr]

Welcome to the forum! I'm relatively new here as well. Lots of helpful folks here.

Maybe I don't know what I am talking about, but assuming your ethernet is 100Mbs, this seems about right, doesn't it? 54Mbs (wireless g) compared to 100Mbs (ethernet). By right, I mean your wireless throughput is roughly half of your wired.

Do you have DSL or cable or other? Do you have another wireless g computer that gives very different results on the same modem/router setup?

[ginahoy]

...assuming your ethernet is 100Mbs, this seems about right, doesn't it? 54Mbs (wireless g) compared to 100Mbs (ethernet). By right, I mean your wireless throughput is roughly half of your wired.

Hmm... Neither network "sees" the other. It's not like the two get together behind my back and agree to preserve the same ratio based on their respective maximum capacities.

My DSL modem should be the bottleneck, as noted in my original post. The highest d/l speed I've recorded is about 650 KB/s. Keep in mind that 802.11g can handle 54Mb/s, which is 6,750 KB/s (where B=byte and b=bit), which is 10x my max DSL download speed. So unless someone can explain otherwise, I can't see 802.11g being a bottleneck in real download speeds.

I've seen reports from others that say they get over 80% of internet connection speed via wireless. I want some of that, as I'm considering a wireless Netflix-enabled Blu Ray player.

[RealBlackStuff]

You could replace your router and wifi card(s) with an N-option.
With dual-channel 2.4/5GHz and a decent wifi card, speeds up to 300/450 Mbit/s are theoretically possible, compared to wifi-G @ 54 Mbit/s.

[ParatoOptimal]

Does the X60s have a third antenna for 11n?

[RealBlackStuff]

No, but cards like the 1/2 size MiniPCIe Intel Ultimate-N 6200 only require 2 antenna wires.

[ParatoOptimal]

do you ahve an FRU#?
I searched ebay for Ultimate-N 6200 and found nothing.
Thanks

[RealBlackStuff]

I made a small mistake, it's the Intel Advanced-N 6200, a.k.a. 622ANHMW.
On eBay for ~$20.-
Don't know an IBM/Lenovo P/N or FRU, but with a modified BIOS (whitelist removed), any version will work.

[ginahoy]

I should have mentioned this: I transferred a 700 MB file from desktop (via Ethernet) to laptop (via wireless). The average throughput was ~2,200 KB/s! (17Mb/s). This rules out bandwitdth, reception and interference issues. No?

Based on what I've read, it's not unreasonable to expect 802.11g throughput to approach 80% to 85% of Ethernet download speeds (obviously, wi-fi imposes some overhead). I just need to figure out why I'm not seeing anywhere close to that performance. I would be very hesitant to spend the bucks on a "N" router and network adapter until I can identify my bottleneck.

[RealBlackStuff]

Your T42 most likely has Gigabit ethernet rather than 10/100Mbit.
Where did you measure the throughput, on the desktop or the laptop?
Are you using Access Connection on the laptop, or is Windows taking care of it?

[ginahoy]

Your T42 most likely has Gigabit ethernet rather than 10/100Mbit.
Where did you measure the throughput, on the desktop or the laptop? Are you using Access Connection on the laptop, or is Windows taking care of it?

I just drug the file from the desktop folder (a network share) to the laptop. The laptop was not connected via Ethernet. The Windows XP file transfer progress dialog box doesn't show transfer speed, only the remaining time. So I used stopwatch to time the transfer (317 seconds for 700 MB file).

[ginahoy]

I've been looking for "n" rated mini-PCI card for the T42. No joy so far. However, I did find a n-class PCMCIA card. Does anyone know if that interface might create a bottleneck?

[ajkula66]

ginahoy wrote:

I've been looking for "n" rated mini-PCI card for the T42.

There are Atheros-chipped mini-PCI "n" cards on feebay that will work in your T42 with the "1802 hack" applied.

[ginahoy]

There are Atheros-chipped mini-PCI "n" cards on feebay that will work in your T42 with the "1802 hack" applied.

Thanks. I'll take a look. Will original antennas work with an n card? I'm hoping to use 5Ghz.

[ajkula66]

The card I'm referring to only has two connectors and will work with your antennae, I honestly doubt that you'll be able to run 5Ghz, but I haven't tried it myself.

[ginahoy]

The card I'm referring to only has two connectors and will work with your antennae, I honestly doubt that you'll be able to run 5Ghz, but I haven't tried it myself.

Thanks. It's so hard to search for such things on ebay. THere are literally thousands of cards, and those that might be compatible with thinkpad don't necessarily say so in the listing title. One n card I found has what the seller refers to as a 3x antenna connection, so I guess I'll pass on that.

What about PCMCIA? That sounds so much easier (http://tinyurl.com/3ssy9r2)

[ajkula66]

PCMCIA will work, but why not utilize the antennae that you already have? You'll get a much better reception that way...

[ajkula66]

Here you go:

http://cgi.ebay.com/Atheros-AR5008-AR54 ... 20b5050a2f

Not affiliated with the seller in any way, proceed at your own risk.

Good luck.

[ginahoy]

PCMCIA will work, but why not utilize the antennae that you already have? You'll get a much better reception that way...

Ok, that's what I needed to know. I guess there's not much room for an antenna in those cards!

And thanks for the ebay link. Although I'm familiar with the 1802 hack, I was searching (in description) for cards that mentioned T4x OR 1802. I didn't realize I could use just any mini-pci card. Knowing that helps a lot!

[ginahoy]

Ok, so I'm looking at N-class routers and see that some support 150Mbs and some support 300Mbs. Will the stock antenna set (Main/Aux) support 300Mbs?

[RealBlackStuff]

Read this: http://www.dslreports.com/forum/r205958 ... n-N-router
When you buy this type of hardware, go for the biggest, in this case 300.
Some already claim to work at 450.
OTOH if your laptop has a Gigabit ethernet port, buying a gigabit router and using an ethernet cable between router + laptop gives you even more speed.

[ParatoOptimal]

I just bought 2 x 2200 cards for my X31 and T41.
Would the 622ANHMW work in those?

[RealBlackStuff]

No, that's a MiniPCIe(xpress) card.

[ginahoy]

Here you go:...[snip]

Thanks for the link. I contacted technical support reps at D-link and Rosewill and both confirmed that a legacy antenna shouldn't impact an N card's ability to establish a 300 connection, but it would affect range (no issue for me). However, both techs said the card (and O/S) must support WPA2 security (presumably AES), otherwise the connection will be limited to 54 MBs under 802.11n rules. This is discussed by Tim Higgins here, in Fix #4, although he acknowledges some non-compliant products may violate this rule.

Unfortunately, the eBay listing for this mini-pci N class card (and the dual band 5Ghz card from same seller) doesn't mention support for WPA2, only WEP. I contacted the seller and he agreed to do some testing. But even if he confirms N speeds, it may just be that he's using a non-compliant router. I would feel better if I knew for sure the card supports WPA2. Hopefully it's just an omission.

The card I'm referring to only has two connectors and will work with your antennae, I honestly doubt that you'll be able to run 5Ghz, but I haven't tried it myself.

Do you have one of these cards? Can you confirm if it supports WPA2? I would be most grateful!

I found another mini-PCI n-card on newegg: the TP-Link TL-WN861N. Anyone know anything about this card? At least the specs confirm it supports WPA2. If it turns out that the no-name cards on eBay support WPA2 after all, then I would be inclined to buy a 5Ghz router.

[ajkula66]

@ginahoy:

Any card that is "N" capable supports all WPA encryptions, otherwise it wouldn't have been able to work in the "n" standard, be it DRAFT or the accepted one. It's a sad state of affairs when a seller is clueless about his/hers merchandise, but that seems to be the unfortunate norm of eBay these days.

Atheros chipsets have been enabled for WPA since at least 2004...all of them.

My understanding is that the card in question does not operate in the 5Ghz band. I don't own any of them, BTW.

[ginahoy]

My understanding is that the card in question does not operate in the 5Ghz band

My bad. This same seller also lists an n-class mini-pci card that supports 5Ghz (I edited previous post to reflect this). Here's the link: http://tinyurl.com/3rdpx2s

I just received reply from seller and he confirmed WPA2. Not surprisingly, I found several websites that reference this same card, including a bulk quantity importer, and they all show the same exact specs, errors and all. Apparently WPA2 was just an omission in the first instance that has been propagated by the various resellers.

I'll report my results after I get a new router and card. Thanks for all the help!