|At a Glance|
|Product||D-Link Xtreme N Gigabit Router (DIR-655 A4)|
|Summary||Market-leading single-band draft 802.11n router|
|Pros||• Gigabit WAN and LAN with excellent routing speed
• Automatic QoS for Internet uplink and WLAN
• USB device sharing
|Cons||• USB device sharing is one Windows client at a time|
Our review of the original DIR-655 is one of our most-viewed wireless router reviews, befitting its status as one of the most successful draft 802.11n routers. Since its original release, D-Link has continued to enhance the product, adding 9K jumbo frame support awhile back for its gigabit Ethernet switch and more recently adding its SharePort USB-sharing feature (see this part of the DIR-825 review for the quick poop on SharePort).
The other thing that D-Link has done is rework the 655's innards, mainly with an eye for manufacturing cost reduction. The current revision is A4 and the natural question is whether D-Link has sacrificed performance along with reducing cost.
Figure 1 is a shot of the original 655 with its top cover removed. It used a mini-PCI radio and nice metal heatsinks on the Ubicom 5160U SoC and Vitesse VSC7385 Gigabit Ethernet switch. 16 MB of RAM and 4 MB of flash made up the rest of the design.
Figure 1: DIR-655 original inside view
The mini-PCI radio module was an Atheros AR5BMB71 reference design using an AR5416 Baseband / MAC and AR2133 3T3R 2.4 GHz radio.
Figure 2: Original mini-PCI radio module
Figure 3 shows the A4 version board. The radio has been integrated into the main board and uses a more recent Atheros chipset consisting of and Atheros AR9160 BB/MAC and AR9103 2.4 GHz 3x3 MIMO radio. I removed the ceramic heatsink pads and confirmed that the Ubicom IP5160U was still used as the router SoC. Lifting the pad on the larger device, however, showed that a Realtek RTL8366SR Gigabit switch was now used instead of the Vitesse device.
Figure 3: DIR-655 A4 board
Table 1 shows a slight improvement in routing performance, probably due more to the newer firmware than any hardware changes.
|Test Description||A4 Throughput - (Mbps)||Original Throughput - (Mbps)|
|WAN - LAN||
|LAN - WAN||
Table 1: Routing throughput
Figure 4 shows what the throughput variation looks like for the WAN to LAN, LAN to WAN and simultaneous routing throughput tests.