Over the last couple weeks, we received a lot of great feedback from our readers about the iPad, but we also received quite a few complaints, especially when it comes to WiFi. To check whether these issues are isolated or widespread, we decided to submit 3 of our iPads to a series of tests in order to assess their wireless performance.
To keep it simple, we mainly focused on signal quality, as well as the average download speed the devices could sustain. All tests were performed using 2 different routers, to make sure the results were not tied to a specific brand/model. We tested both 2.4GHz and 5.0GHz bands, and all tests were performed in an urban area with a decent amount of interference (Dallas-Fort-Worth metroplex), around noon on April 20th, 2010. We also used a MacBook Pro and a Windows Tablet PC using WiFi chipsets from the same family as the iPad’s, for comparison purposes. The results are in.
- iPad (WiFi-only model): iPhone OS 3.2, 16GB Flash, WiFi via Broadcom BCM4329XKUBG (basically a BCM4322AG with Bluetooth support, driver version unknown)
- MacBook Pro (late 2009): OS X Snow Leopard 10.6.3, 2.8GHz Core 2 Duo, 4GB RAM, WiFi via Broadcom BCM4322AG (driver version 184.108.40.206)
- HP Tablet PC (tx2500): Windows XP SP3, 2.0GHz Turion X2, 2GB RAM, WiFi via Broadcom BCM4322AG (driver version 220.127.116.11)
- NetGear WNDR3700, firmware 18.104.22.168NA
- D-Link: DGL-4300, firmware 1.22NA
- Test 1: Open field, devices 20ft away from the routers
- Test 2: Open field, devices 40ft away from the routers
- Test 3: Open field, devices 60ft away from the routers
- Test 4: Routers inside a house, devices 20ft away from the router (1 wall between the routers and the devices)
- Test 5: Routers inside a house, devices 40ft away from the router (2 walls between the routers and the devices)
- Test 6: Routers inside a house, devices 60ft away from the router (backyard, more than 3 walls between the routers and the devices)
- Signal strength: Level received at the router (information provided by the DGL-4500)
- Speed test: Mix of content download as well as raw http performance tests via speedtest.net, repeated 10 times for each test, and averaged out (normalized to a scale going from 0 to 100, 100 representing the best throughput we could measure)
Let’s be clear, the iPad performed decently, but performance was not on par with the MacBook and the HP Tablet PC. First things first, range. It is obvious that the iPad’s WiFi range is limited compared to the other devices, very likely due to the fact that the Wifi antenna is hidden behind a thick piece of aluminum and plastic (behind the Apple logo, on the back). And within the over-crowded 2.4GHz band, the iPad had a harder time to stand out of the crowd, compared to the Mac and the PC.
When we used the much less crowded 5.0GHz band, the iPad’s signal strength was much higher, and actually beat both PC and Mac, at least for close to medium range tests. However, in a normal environment such as a house, the results were less convincing, and the iPad eventually lost its connectivity when we went too far from the router, while the PC and the Mac managed to remain connected.
When it comes to throughput, the iPad was on par with the Mac and the PC for the open field tests while in a close range, but as soon as we used it in a enclosed environment, the WiFi throughput performance on the 2.4GHz band was still decent, but was in most cases not higher than 2/3 of the throughput we managed to get from the Mac and the PC.
As for the 5.0GHz band, the iPad did very well in open air tests, and fared better than on the 2.4GHZ band, which confirms the high signal strength measured by the DGL-4500. On the other hand, as soon as the iPad was introduced to a more hostile environment, the results we obtained were again about 2/3 of what we could see with the Mac and the PC. Note that the last test was really tough on our iPads, as the throughput was extremely low, which is in line with the poor signal strength/quality assessed by the DGL-4500 for this specific test.
Overall, the iPad’s WiFi performance was ok, but clearly not in line with what we measured with the Mac or the PC. When you add this to the fact that the iPad also has other network issues such as a buggy DHCP implementation, it feels like the iPad was a bit rushed out of the door when it comes to networking.
Hopefully these figures will get better over time as Apple and Broadcom fine tune their WiFi drivers for the iPad, but meanwhile:
- Try to stay fairly close to your WiFi router. The farther you go, the more likely the iPad will lose its connection, even in locations where your laptop can still connect to your WiFi network. Based on our tests, trying to go beyond 2 walls between the router and the iPad is too much.
- Switching the iPad’s WiFi on and off can help if you experience problems, especially if your iPad was in sleep mode for a long time.
- Try to switch your router from 2.4GHz to 5.0GHz or vice-versa, to see if things get better. 2.4GHz offers longer range but is overcrowded. 5.0GHz experiences much less interference, but range can be severely limited.
Editor’s note: Your mileage may vary, depending on your location, the configuration of your house, the location of your router, as well as the amount of interference you may experience from other WiFi networks and cordless phones.