Share your experience with PCMCIA Ethernet cards

[t43_guy]

Hello all, I wanted to have an extra ethernet interface in my T43 and thought it was a cool idea to use the PCMCIA features of this computer, so this week I bought a D-Link DFE-670TXD because the integrated connector design looks robust and I read it works under Linux. When testing it I immediately noticed that even though the card is marketed as 100/10 M it barely reaches 7 Mbit/s! (about 700 KB/s). I tested it under Windows XP, Linux Debian and even OpenBSD and it's slow in all of those OSes, I also noticed that when there's a lot of traffic flowing through that card the software interrupt CPU time usage shown in top under Linux goes to 100%, which leads me to believe that this cheapo card only has an ethernet transciever and most of the packet processing is done in software on the host computer CPU, just like old softmodems.

7 Mbit/s is unusable for me, even just browsing the web is slow with this card but since it is 16 bit instead of 32 bit PCMCIA it may still be useful for older thinkpads that only have a modem and maybe to use it as an SSH management interface. This D-Link card gets autodetected and works out of the box under Debian 10 and OpenBSD 7.0 but it's dog slow though.

I found this website which talks a lot about the NE2000 design used in this card, it might be an interesting read http://www.os2museum.com/wp/was-the-ne2 ... -that-bad/

I also found a post in this forum about someone who used this same card on a ThinkPad 600 and noticed the same problems as me viewtopic.php?f=6&t=29796&p=194856#p194856

So now I have to buy another card, I would love to get one of those Gigabit Expresscard or Cardbus cards but those aren't available in local stores, I have these options at hand:

-3com 3CXFE575BT xJACK CardBus card
-CNET CNF401 CardBus card

Do you have any experience with any of them? I would like to know if the 3com card doesn't have any of those performance issues, because it looks promising.

Also feel free to rant about any ethernet PCMCIA card you've used in the past as this may help other people.

[theterminator93]

I have a Gigabit CardBus card I use with my T601F. Unfortunately a malfunctioning PoE injector fried the integrated GbE port on it a few years ago while I was out on the job...

The one I bought and use is a D-Link DGE-660TD. Seems to work quite well. I haven't done throughput tests on it but I remember being satisfied with the data rates when I was copying ISOs to VMWare hosts.

[t43_guy]

Yep D-Link hardware is usually decent, I own myself a D-Link DWL-G630 CardBus bg wifi card and it's rock solid, connections are stable and speed is just a little bit higher than the internal intel mini pci intel card. I guess I just bought an old oddball card :p

Also my T43 freezed today when I was using this 670TXD card, this is probably an issue with the linux driver as I noticed the same behaviour running Arch Linux on a different T43.

[RealBlackStuff]

If you can find it, the best/fastest card for the T43/R52 is this Mini PCI:
TP-Link TL-WN861N, 300Mbps, wifi b/g/n

[axur-delmeria]

It's likely that the bottleneck is in the 16-bit interface of your D-Link DFE-670TXD. That, or a configuration error that ends up crippling the I/O performance.

I had a Xircom Cardbus 10/100 which also had a 56k modem.



I don't remember the speeds I got from the LAN part, but it's probably decent (much better than the 0.7Mbit/sec you've experienced. That said, I never got to push it to its limits because my laptop at the time was a Thinkpad 760XD with Pentium MMX 166MHz processor.

From my experience, 3Com cards are good. I had a 3Com 10Mbps XJack PCMCIA card that served me well, and only failed because the internal flex cable for the XJack cracked/tore due to age. Note that I got that card second-hand, and it probably had seen many years of service beforehand. You should take that into account, given the age of these devices.

A quick search on Amazon shows this Startech Cardbus LAN card, which seems to fit your requirements: https://www.amazon.com/Cardbus-PCMCIA-1 ... B000085BAX

[t43_guy]

Thank you, that's the kind of info I needed to know. I'm aware the xJACK connector is fragile so I will keep that in mind when asking the seller.

You made me remember that 16-bit PCMCIA cards do not support bus mastering which means all data that goes through the card needs to be handled by the CPU no matter what, whereas 32-bit cards can use DMA and do their job without bothering the CPU, I'm feeling confident that the 3com card will be ok. I'll ask the seller some questions and if everything seems fine I'll order the card

[Enig]

Hey,

Been using a PCMCIA 3COM 574BT 10/100 for a while on a bunch machines - mostly with imaging from dos prompt in mind, but don't remember having any issues like what you are describing.
Have used it on quite a few of the older machines in my collection including a T40 and An X41.
I remember the slowest being the 600 at 3.5 MB (not Mbit) p/sec. I don't recall clearly but I think the X41 was around double that,

Even if the card is poorly implemented and leaning heavily on CPU - using 100% CPU strikes me as odd. Certainly on a 486 and probably on a Pentium1, but not a Pentium M.
Maybe a software/driver issue?

Anyhow .. +1 for the 3COM. Have good experience with those.

[t43_guy]

Good news

I ordered the 3com card and instead of the BT card I got a 3CXFE575CT, which looks about the same but apparently has support for wake on lan. Performance is what I would expect from a 100 Mbit card, it tops at the maximum speed and just uses about 20% CPU when running at full load under Linux. This card also supports wake on lan although I haven't tested it yet and the LEDs work fine as well. The XJACK connector on this card had one of the pins a little bent but nothing to cause trouble, the mechanism in it is working fine. I would definitely recommend this card, thanks everyone for helping me choose a card!