Wireless Performance - Comparative - more
You may remember at the top of the review that I mentioned performance problems found with both the C7 and D-Link's DGL-5500. My initial results with the C7 showed very low throughput in the 90° and 270° runs as shown in the composite plot below. I'm showing just the uplink plot, but downlink results were similar.
Four test runs - 2.4 GHz downlink - TRENDnet TEW-812DRU
Long story short, the problem turned out to have nothing to do with the router's orientation. Instead, according to QCA, it was caused by "non-typical" behavior during intial connection setup of our standard Broadcom-based ASUS client (PCE-AC66). The behavior was allowing the ASUS client to connect to the router, but only with very low throughput because frame aggregation was not allowed.
QCA found that frame aggregation, and normal throughput, would start if smaller test file sizes were used or if the test were run longer than the one minute I use. The good news is that once the high-throughput kicks in, it stays enabled as long as the client and router stay connected. There was really no reason given why I saw the problem only with certain orientations of the router in the test chamber. Just the way my setup happened to work, I guess.
QCA gave TP-LINK a fix to work around the Broadcom "non-typical" behavior a little over a week ago and it is currently in testing. But I decided to go ahead with the review since people should know what they are getting into if they buy the C7 right now.
To work around the problem without the new firmware, all I did was to run a short manual test before the automated run to ensure that the router had switched to high throughput mode. Once TP-Link releases new firmware, I will retest the C7 to make sure that it produces the high throughput it is supposed to without any futzing around.
The Router Ranker shows the Archer C7 tied in second place with the ASUS RT-AC66U. Not bad for TP-LINK's (and QCA's) first effort in an AC1750 class router. The C7's weakest points are its 2.4 GHz downlink throughput and range. 5 GHz performance received a #5 rank, but its range ranks #1 for both up and downlink.
TP-Link Archer C7 Ranking Performance Summary
Now that there is another major chipmaker in the 802.11ac mix, the salad days of (relatively) high margins are coming to a close and router makers will now engage in the race to the bottom that comes with all new technology. And this, in a standard that is yet to be released. $150 seems to be the new $200 for this class of router, which is where both D-Link's DIR-868L and the C7 now sit.
The only buyers who need to be concerned with the intermittent low-throughput problem I found are those with Broadcom-based draft 11ac clients. The ones I know of are ASUS' PCE-66U (PCI-e) and NETGEAR's A6200 (USB 2.0). Linksys' AE6000 uses Mediatek silicon and its WUSB6300 uses Realtek. And at any rate, new firmware should be out soon that fixes the problem permanently.
Although the market share leader in China, TP-LINK has been most known in the U.S. for "me-too" products focused on value, i.e. low cost. But if they keep making products like the Archer C7, with plenty of features, strong wired and wireless performance and competitive pricing, they might be on their way to changing that image.