|At a glance|
|Product||Linksys Max-Stream AC2600 MU-MIMO Smart Wi-Fi Router (EA8500) [Website]|
|Summary||QCA based AC2600 MU-MIMO enabled router with Gigabit Ethernet ports and USB 2.0/eSATA/USB 3.0 storage and printer sharing|
|Pros||• Supports bridged router, wireless bridge & wireless repeating|
• MU-MIMO support provides moderate total throughput improvement
|Cons||• No outbound port/service filtering|
• You'll need to buy new devices to benefit from MU-MIMO
Typical Price: $273 Buy From Amazon
Linksys' Max-Stream AC2600 MU-MIMO Smart Wi-Fi Router is the first of the second-generation Qualcomm Atheros (QCA)-based 4x4 routers to hit the market. This new generation gets a bump from 600 to 800 Mbps maximum link rate on the 2.4 GHz side due to QAM-256 support on the additional radio. But the real potential of AC2600 class routers is that their MU-MIMO feature is actually working.
In contrast, all first-generation 4x4 AC2350 (aka AC2400) class routers used Quantenna's QSR1000 4x4 radio on the 5 GHz band. Although I saw a MU-MIMO demo at the company offices about a year ago, not one manufacturer of the first round of 4x4 routers has announced even its intention of removing the "ready" from their MU-MIMO "feature".
The EA8500 is physically similar to the company's E8350 first-generation 4x4 router as shown in the comparison shot below. The EA8500's antennas are taller than the E8350's peek-a-boo antennas. But since Linksys didn't spec them or make a note of their having higher gain, I'm guessing the two antenna gains are the same.
The cases of both products are largely perforated top and bottom and have vent slots on the front and sides, providing ample airflow. Both routers also have screw mounting slots on the bottom that will orient the back panel connectors up, left or right, but not down.
EA8500 vs. E8350
The EA8500's back panel is virtually identical to the E8350's, except for a missing power indicator. That's because the lighted Linksys front panel logo has returned, which also flashes, pulses or shines steadily to indicate internet connection status, booting and firmware updates.
All Ethernet ports are Gigabit and each has separate link and activity LEDs. Like the E8350, WRT1900AC and WRT1200AC, you get one USB 3.0 port and a shared USB 2.0 and eSATA (eSATAp) port.
MU-MIMO: Why should I care?
Three words: total throughput improvement. MU-MIMO vs. XStream: The Coming Battle For Wi-Fi Airtime described the basic approaches of the two major competitors in this latest Wi-Fi battlefield. To recap, Broadcom's XStream is a proprietary technology that adds a second 5 GHz radio and mechanisms to automatically assign devices to radios based on link rate and signal level; the two main factors that determine how much airtime a device needs to move a packet of data through the air.
MU-MIMO is part of the 802.11ac standard, using an advanced form of beamforming to enable simultaneous AP-to-client transmission for downlink traffic only (AP to STA). The diagram below from a QCA presentation illustrates MU-MIMO's effect, which is to move from one client transmission to multiple transmissions in each on-air timeslot. The freed-up airtime can be used for "legacy" (802.11a/b/g/n) and single user (SU) MIMO (SU-MIMO) clients, providing benefit to even mixed-device WLANs.
Single User vs. Multi User MIMO Throughput
Image credit: Qualcomm Atheros
Notice the example shows three MU-MIMO streams from a four-stream (4x4) access point (AP), which is due to MU-MIMO's # of streams-1 client rule. This is a by-product of practical limitations in the technology used in MU-MIMO devices.
Linksys returned to requesting short-term confidentiality for key FCC ID docs. So after I finished testing, I opened up one of the two EA8500's Linksys sent, for the photo below.
Linksys EA8500 inside
At least the upper right portion of the design is similar to the E8350's shown below, with a similar heatsink-topped shield covering the Qualcomm IPQ8064 dual-core Internet Processor clocked at 1.4 GHz and 512 MB of Samsung DDR3 RAM. The same QCA8337 Gigabit switch is seen below the Ethernet jacks at photo center.
It took more effort than usual to get the RF can tops off, but I finally did, revealing the QCA9980 11ac MU-MIMO radios and associated transmit power amplifiers. If my eyeballing of the connections is correct, that internal antenna is connected to the fourth 2.4 GHz radio, which also appears to connect to the right rear external antenna. I don't know what its function is.
Linksys EA8500 inside - components revealed
Table 1 has a comparison of the EA8500 and E8350's components.
|Linksys EA8500||Linksys E8350|
|CPU||Qualcomm dual-core IPQ8064 Internet Processor @ 1.4 GHz||Qualcomm dual-core IPQ8064 Internet Processor @ 1.4 GHz|
|Switch||Qualcomm Atheros QCA8337||Qualcomm Atheros QCA8337|
|RAM||512 MB||512 MB (Qualcomm/QCA)
128 MB (Quantenna)
|Flash||128 MB||128 MB|
|2.4 GHz Radio||- QCA9980 4-stream 802.11ac MU-MIMO radio
- Skyworks SE2623L 2.4 GHz power amp (x4)
|- QCA9880 3-stream 802.11ac radio solution
- Unidentified 2.4 GHz power amp (x3)
|5 GHz radio||- QCA9980 4-stream 802.11ac MU-MIMO radio
- Skyworks SKY85405 5 GHz power amp (x4)
|- Quantenna QSR1000 (QT3840BC Baseband & QT2518B RF)
- Unidentified 5 GHz power amp (x4)
Table 1: Component summary
The E8350's QCA9880 2.4 GHz radio doesn't support standard 802.11ac beamforming. But since the same QCA9980 radio is used for both 2.4 and 5 GHz, you get beamforming on both bands. MU-MIMO works on 5 GHz only.