D-Link Xtreme N DIR-685

With a 120GB Fujitsu MHW2120BH installed and a 2GHz Core 2 Duo PC with a 1GB Ram disk (to avoid bottlenecks) attached the other end, transfer speeds maxed out at around 12Mbytes/sec. That’ll be acceptable for most home users, although most dedicated Nas boxes are between two and four times faster.

Good Wi-Fi speeds when placed close together, but no killer 5GHz mode
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On paper, the 802.11n Wi-Fi component of the package has a lot going for it. A Ralink RT2880F system on chip, ticking over at 266MHz, sits inside, which Ralink sells with 2.4/5GHz transceivers. We had a play with one of the DIR-685’s predecessors, the DIR-855, a while back and found its 2.4/5GHz Wi-Fi an absolute blast to work with.

It can take just three dual-channel (40MHz) routers in the 2.4GHz band to clog up the airwaves and seriously slow down your Wi-Fi. Even if all 802.11g homes are sensible and use just one 20MHz channel each, there’s only space for six routers on a street. It sounds confusing when there are 14 channels in use in Europe – the terminally keen can find out more about 2.4GHz and 5GHz Wi-Fihere.

If you can detect more networks than that from your home, then upgrading to 5GHz kit should benefit you. For starters, there are very few homes with 5GHz kit and secondly there are 12 non-overlapping single channels (six dual channels), so many more networks can occupy the band without slow-down.

However, the 5GHz band isn’t enabled on the DIR-685, but speeds were good nonetheless. In a typical, noisy, London suburb the DIR-685 averaged 85Mb/s in our synthetic TCP test, and 70Mb/s in a real world Windows Explorer 350MB copy test using an Atheros AR5008 – the Wi-Fi chipset found in many 13in MacBooks.

Avoid the standard TKIP setting, says D-Link (and us)
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We initially had compatibility problems between the DIR-685, the AR5008 card and a TrendNet TEW-621PC card. The two Wi-Fi cards would only connect at 802.11n speeds when encryption was turned off. With WPA/WPA2 turned on, the TrendNet card wouldn't connect at all, while the AR5008 would only connect at 802.11g speeds.