Can you upgrade a laptop from an 802.11b/g to an "a" or other 5GHz compatible WLAN card?

Question

And if so, is it worth it? All of my other devices run much faster and have stronger signals and are connected on the 5GHz channel (they are also obviously newer so...). I have replaced hard-drives in laptops before and am somewhat familiar with getting in there, but would love some feedback. Thanks in advance!

Answer 1

It's not impossible to replace the internal card, but it's pretty difficult to do it well, for reasons I'll detail below.

There have been three fairly common form factors for laptop internal wireless cards: "Mini PCI", and "PCI Express Mini" (PCIe Mini), and half-height PCI Express Mini (or "PCI Express Micro"). Mini PCI was more common in the PCI and 802.11b/g days up to about 2006, and PCIe Mini has been more common in the PCIe and 802.11n and 802.11ac era since about 2006. If you bought your laptop after 2006 but it still only came with a b/g card, it's hard to guess which form factor card it has.

If you have a large cheap clunky laptop, it has a better chance of using a standard form factor card. If you have an ultrabook or Mac or other slim, small, highly styled design, your laptop vendor may have opted for a custom card form factor to fit in where space is at a premium. So there's no guarantee that you have a standard form factor card. You'll have to get in there and look, so you know what kind of replacement to order (assuming it's one of the three standards).

One problem of upgrading from b/g (or 2.4GHz-only b/g/n) to a/b/g or a/b/g/n or a/b/g/n/ac is that your laptop's antennas (which are not part of the card on internal cards) are probably optimized for 2.4GHz only, not dual-band 2.4 + 5 GHz operation. Radio waves don't travel as far in the 5GHz band anyway, so having antennas that are bad for 5GHz to begin with just makes things that much worse.

Another gotcha to look out for is the number of antennas. B/G (and A) only really required one antenna, whereas N and AC radio designs typically require 2 or 3 (although there are some lame versions of N and AC that only use a single antenna). So you need to see how many antenna leads you have connected to your card, so you know what kind of radio to get to replace it with. If your card only has one antenna lead connected to it, you may have to buy one of those "lame versions" of N or AC cards that I was talking about, that only use one radio chain. But then again, you said you wanted 5GHz operation, and typically the lame single-radio-chain 802.11n designs are that way because they wanted to be cheap, so they usually cheaped out and don't support the 5GHz band either. So it might be hard to find a single-radio 802.11n card that supports both bands.

Also note that some Wi-Fi cards are actually Wi-Fi/Bluetooth combo cards. If your laptop has Bluetooth, and you use Bluetooth, you may need to see if your card is a combo card, so you know if you need to order a Wi-Fi/Bluetooth combo card to replace it. If you can't get a combo card, you could consider buying a Bluetooth USB dongle.

Also note that Wi-Fi/Bluetooth combo cards may have one antenna lead for the Wi-Fi chip, and a separate antenna lead for the Bluetooth chip. Or they may share a single antenna. Or there may one dedicated antenna for Wi-Fi, and the other one is a shared Wi-Fi/Bluetooth antenna. It's almost impossible to know, unless you can find detailed technical documentation for the module you're replacing. If you replace a combo card with another combo card, you'll probably want to think about how you're going to hook up the antennas you have to the new combo card.

As far as antenna connectors go, they're almost always those tiny "u.fl" connectors unless you're talking about a laptop from a decade ago. So that's not likely to be a problem.