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More than a year after the first products based on an initial draft of the superfast 802.11n Wi-Fi standard arrived, a second draft--reinforced by Wi-Fi Alliance certification--appears to have solved the interoperability and stability problems we saw in the initial crop. But our informal tests of the first certified products also suggest that prices and performance vary widely as a result of issues that are unrelated to the standard.

We tested Belkin's $90 N (F5D8233-4), Buffalo's $99 AirStation Nfiniti (WZR2-G300N), D-Link's $180 Xtreme N Gigabit (DIR-655), and Netgear's $130 RangeMax Next (WNR834Bv2) first with their own matching PC Cards and then again with PC Cards made by each of the other three vendors. Connection utilities showed that in our tests at a midrange distance of 20 feet, all of them connected at theoretical single-channel draft-n speeds of up to 130 megabits per second (mbps). The Buffalo and the D-Link proved the fastest (see our chart on the next page), and the Buffalo's sub-$100 price makes it a good deal.

But actual throughput for different router-PC Card combos varied widely, from 6 mbps to 35 mbps. Why? In part, different chip sets are responsible; also, the routers and PC Cards had either two or three transmitting and receiving antennas. Generally the greater the number of antennas, the faster (and pricier) the gear.

Check Model Numbers

Some vendors are offering multiple draft-n products with different antenna arrays and other options, such as the D-Link's gigabit ethernet (which typically adds $50 to the price). Differences aren't always obvious from product names, so shoppers should note model numbers.

Draft-2.0 Wi-Fi certification also ensures compatibility with 802.11b/g and, when specified, 802.11a gear, and with the Alliance's WPA2 (Wi-Fi Protected Access) and WMM (Wi-Fi Multimedia) specs for security and streaming multimedia, respectively. As 802.11n is optimized for WPA2's strong AES encryption, AES improves performance compared with older (and weaker) software-based WEP and WPA security.

Nearby Wi-Fi networks using the 2.4-GHz band (all 802.11b/g networks qualify, as do 2.4-GHz 802.11n networks) can slow things down. Draft 2's "good-neighbor" policy (but not Wi-Fi Alliance certification) requires stepping down to single-band 20-GHz channels (the dual-band 40-GHz mode enables the fastest speeds) when a 2.4-GHz network that might otherwise be crowded out is sensed. This happened often enough that we decided to test in single-channel mode.

The bottom line for shoppers: Don't worry about interoperability, but be aware that performance will vary widely based on your equipment and on factors, such as nearby networks, that are beyond your control. No matter what you buy, coverage and throughput should be better than with older 802.11a/b/g gear, but look beyond the Wi-Fi Alliance's logo to choose the features you need.