SmallNetBuilder

Introduction

At a glance
Product	NETGEAR WNDR4000 N750 Wireless Dual Band Gigabit Router   [Website]
Summary	Latest NETGEAR top-of-line dual-band, dual-radio 802.11n router with bandwidth metering and external USB drive sharing w/ UPnP AV / DLNA media server.
Pros	• Gigabit ports • Guest WLANs on both bands • IPv6 support • WDS repeating / bridging
Cons	• 2.4 GHz low-signal performance • Three stream N on 5 GHz band only • Does not support WEP

Hope springs eternal for improved wireless performance each time a new wireless N router is introduced. And that hope is usually soon dashed once people get it home and realize that it isn't any better than the N router they hope to replace.

NETGEAR seemed to take a step backward (or at least sideways) in 5 GHz performance when it changed the antennas in the WNDR3700V2. This time, with the WNDR4000, they seem to have messed up 2.4 GHz performance in the quest to bump up the "N" number from 600 to 750.

If you're not familiar with the trick the NETGEAR marketing wizards try to pull on unsuspecting buyers, the "N" number is the total of the maximum link rates of both radios. With the dual two-stream N radios on the WNDR3700, that number is 600, i.e. 300 Mbps from the 2.4 GHz radio and 300 Mbps from the 5 GHz radio, when both are configured in channel-bonded 40 MHz bandwidth mode.

With the WNDR4000, the 750 comes from 300 Mbps for the 2.4 GHz radio and 450 Mbps for the three-stream enabled 5 GHz radio. While a three-stream 5 GHz radio may score marketing points, the only devices that can take advantage of 5 GHz three-stream N are notebooks / laptops with dual-band three-stream cards (like Intel's Centrino Ultimate-N 6300) and three antennas. If you're looking to upgrade current gear, the only three-stream N capable bridge so far is TRENDnet's TEW-687GA, but it's 2.4 GHz only.

So the WNDR4000 joins the Cisco Linksys E4200 as the second router to have three stream N on its 5 GHz radio only. If you want three stream on both bands, your choices remain D-Link's DIR-665 and TRENDnet's TEW-691GR.

Aside from a lightening of the front panel bezel to a silvery gray, you'd be hard-pressed to tell the difference between the 3700 and 4000. The lights and buttons on the front panel are the same.

Figure 1: WNDR4000 front panel

And so are the Gigabit WAN and LAN ports and USB 2.0 connector on the rear. Pay no attention to the ADSL notation on the yellow jack in Figure 2, which came straight from the WNDR4000 user manual I just downloaded. The WNDR4000's WAN port is Gigabit Ethernet.

Figure 2: WNDR4000 rear panel

Internal Details

In the past, NETGEAR hasn't asked the FCC to delay release of product design data, but they have with the WNDR4000. So after testing was complete, I popped the top off my review sample to see what's inside. The maximum link rates I saw in the web admin told me that Broadcom devices were in use and that's what I found inside. In fact, the design hews very closely to that of Cisco's Linksys E4200.

Figure 3 clearly shows a Broadcom BCM4718 Intensi-fi XLR 802.11n Simultaneous Dual-Band (2.4/5 GHz) Router System-on-Chip, which serves as the main CPU and, if my antenna parsing is correct, 2.4 GHz radio. (The 2.4 GHz antennas are the larger, the 5 GHz, smaller.) Also visible are a Winbond W9751G6JB, which provides 64 MB of RAM and a MXIC MX25L6445, for 8 MB of flash.

Figure 3: WNDR4000 inside view

Getting further details required prying off the RF shields (Figure 4). This confirmed the BCM4718's 2.4 GHz radio role via two SiGE 2528L 2.4 GHz power amps. Under the smaller shield is a Broadcom BCM4331 Single-Chip 802.11n Dual-Band 3x3 and three SiGe SE2594L Dual Band 802.11a/b/g/n Wireless LAN front ends to complete the 5 GHz radio.

Figure 4: WNDR4000 inside view - shields removed

I couldn't remove the heatsink on the switch, since it was soldered down. But since the design is very similar to the Linksys E4200, I'm guessing the switch is a Broadcom BCM53115 Gigabit switch. For your comparison pleasure, I've included the E4200's board photo in Figure 5.

Figure 5: Linksys E4200 inside view - shields removed

So, aside from 8 MB of flash vs. 16 MB in the E4200, different antennas and firmware, the WNDR4000 and E4200 are kissin' cousins.