Compatibility of 802.11 wlan mini-pci cards for the T4x ?

[thinktwice]

Hello,

I'm interested in the criteria to look at when selecting a Wlan mini-pci card, and especially for the ThinkPad T4x series and have many questions.

I observed that the Intel PRO/Wireless LAN 2100 3B Mini PCI from a T40 is not accepted in a T42. From its name, I assume this card is to WLAN what pc-2100s is to RAM; it probably runs at the 266 Mhz frequency.

1) So, my first question concerns frequency : are 802.11 WLAN cards retro-compatible, i.e. capable to work at lower frequencies, exactly like a pc-3200 RAM module at 400 MHz (or a pc-2700 at 333 MHz) accepts to work at the 266 MHz of the pc-2100 RAM ?
Typically, would the wireless mini-pci card from a T42 also work in a T40 ?

2) Secondly, excepted the from factor, are there generations of mini-pci cards; something similar to the incompatibility between the DDR1/DDR2/DDR3 memory modules ?
For instance, would the wireless mini-pci card from a T43 also work in a T40/T41/T42 ?

3) Are there different number of pins available (like between DDR and DDR2/DDR3 RAM modules) ?

4) Are WLAN mini-pci card designed for one processor brand, i.e. are there 802.11 cards designed for Intel processors and others and AMD processors ?

5) Do all WLAN mini-pci cards work at the same voltage ?

6) Excepted the Intel cards, are there other brands of 802.11 cards known for good compatibility with the ThinkPad T4x and providing easily downloadable drivers ?
(I'm especially interested at this when seeing second hand cards.)

7) What about laptop-makers wireless cards ?
For instance, I could see a second hand "Dell Wireless 1370 WLAN", but I fear to not find the driver or that the driver licence not allowing usage on non-DELL laptops.
I especially fear this problem if the OS is Windows.
Any experience here ?

8) Are 802.11 n cards retro-compatible with 802.11 b and 802.11 g or should this be explicitely mentioned on the card, i.e. 802.11 b/g/n ?

Thanks you very much.

[dr_st]

The name confused you. There is absolutely no connection between miniPCI Wifi cards and RAM.

All miniPCI cards are designed to have the same interface - same number of pins same voltage. There are also no compatibility issues related to processors.

There may be some BIOS whitelist issues that will prevent some cards from working in some laptops, based on IBM/non-IBM branding, or specific device IDs / model numbers.

However, I will leave the details to the experts.

[RealBlackStuff]

I won't claim to be that expert, but:
1) nothing to do with frequency. Any miniPCI wifi card can work there (exceptions, see below)
2) no/yes
3) no
4) no
5) yes
6) Atheros-based cards are very popular, with good driver availability
7) Cards are 'classed' by their chipset maker, such as: Atheros, Ralink, Philips, Broadcom, Intel
HP, Dell aet all may put their own label on a card, but it's just that: a label.
as long as they are miniPCI, yes

If you apply the NO-1802 hack to your T42 (or older), you can use any miniPCI card.
If you have T43 (or newer), you need to apply a whitelist-removed BIOS, before you can use any other miniPCI card.