Wireless networking kit based on the draft 802.11n specification has been available for a while, and we've now performed some throughput tests on a range of products built around different chipsets.
This is important, because until the standard is ratified in 2008, there's no guarantee that products from different vendors will work with one another. Nor is there any guarantee that today's Draft-N products will be compatible with 2008's proper 802.11n gear.
So what did we find? Check out our Group Test for the full details, but here's a summary. Draft-N data rates, even at close range, are disappointing: Atheros- and Broadcom-based products delivered between 60 and 80Mbps, while the Marvell-based Netgear RangeMax Next almost reached 100Mbps. This is considerably below the manufacturers' claimed rates of around 300Mbps.
Not surprisingly, interoperability is best among Draft-N products that use the same chipset. In the worst case -- a Marvell-based Netgear adapter talking to the non-Marvell-based routers -- data rates were almost down to 802.11b levels (8-12Mbps).
So if you must buy Draft-N gear, stick with one vendor -- and don't let anyone with 'rogue' Wi-Fi kit log onto your wireless LAN.