Saturday, December 03, 2011

iPad WiFi is poor

My wife just got an iPad – the first tablet in our house.  It was not easy to get it away from her, but last night I managed to take the iPad to bed.  I was expecting an insanely great experience, but my first impression was that network access was slow and flaky.

To test my impression, I compared it to a Dell Precision laptop.  First, I pinged UCLA, a nearby university, 100 times using both the laptop and the iPad.  The average ping time for iPad was 63.7 milliseconds, over twice that of the Dell, and the standard deviation four times as great.  No wonder it seemed flaky.

  Dell iPad
Minimum 18 22.7
Maximum 120 231.9
Mean 30.2 63.7
Standard deviation 14.9 64.8
Next I tested file transfer times (Mb/s), and the laptop was faster:
  Dell iPad
Upload 6.29 1.77
Download 1.83 .17
That was no surprise given the variability in ping times. It doesn't look like I'll be making a lot of Skype calls or watching movies in bed.

My bedroom is at the back of the house, so I checked the signal strength. As shown below, it dropped to around -65 db as I walked from the office, where the WiFi access point is located, to the bedroom.

WiFi signal strength dropped as I walked from the access point to the bedroom.

The laptop is not perfect in the bedroom -- it does better when it is near the access point, but its radio is clearly more sensitive than that of the iPad. iPad Wifi is more like that of a netbook than a laptop.

Notes:
I measured iPad ping time using Typhuun System Scope Lite, the transfer rate using Speedtest.net and the signal strength with Metageek Inssider.

A reader pointed out that the results were affected by my pinging UCLA, which introduced Internet and server variability into the test. I repeated the test, pinging a machine within my house and found the following:

Dell: minimum 1, maximum 90, mean 5.96, standard deviation 12.6 with zero dropped packets (1 sec timeout)
iPad: minimum 5.04, maximum 202.02, mean 18.56, standard deviation 32.49 with 8 dropped packets (1 sec timeout)

Not surprisingly, the iPad remains relatively poor.