I just changed my notebook over from an Acer Aspire with Windows 7 to a Mac Book Air. My applications have remained as constant as they can jumping platforms and my usage is fairly comparable. When I connect to a MiFi with the Mac I blow through my data caps in no time flat and didn't have that problem with the Acer. I did so the other day sitting through a seminar just checking email and doing very light (no video, sound, or flash surfing.

I'm wondering whether it is the way that the Mac Air's Mail is polling my Exchange email server and and wondering if anyone else is running into that. I went through over 2 gigs of data in six hours. On my Windows box, this would have barely moved the needle.

Stu

That's pretty crazy. You probably have something running in the background that's sucking down the data.

What else is running? Are you syncing to icloud or anything like that?

Unless you brought down that amount of data files, I very seriously doubt it was from just polling the exchange server.

You could also try a network monitor like little snitch at

http://www.obdev.at/products/littlesnitch/index.html

which will tell you what is using how much of your internet. The free trail is only good for 30 days, and only for monitoring three hours at a time, but that may help.

Depending on the Mifi you may have the ability to see packets or data coming in and out, I would suggest shutting down everything and bring your software up one by one and see if you can identify what is causing the jumps in data usage if you can't track it a network monitor.

I would check iPhoto and photostream. I noticed the drive of my MBA filling up on its own and found that photostream was constantly downloading our new photos after our last big trip. 1,000 photos at 5-7mb each in photostream, but we took over 3,000 in total and it downloading all of them as we added more.

Also maybe check Dropbox if you use that.

What Mail client are you using to get to MS Exchange ? Could be the behavior of the client is not as optimized as MS Outlook is on Exchange.

Also could be settings for the mail client ... as far as it trying to "cache" an offline copy of past emails and email folders from exchange. If you've got a lot of folders and old emails stored ... and have the marked to be cached for "offline" access this could take a long time to "sync" up ... and would use data until that happens (in this case use WiFi or wired access until that point or disable the "offline caching mode"

Definitely check out Tummy's recommendations ... and What Cordelli mentioned regarding Lil Snitch ... which will give you more details and control ... or if you want a simple network monitor as far as Bandwidth in/out per interface ... try something like iStat Menus

Overall the behavior should be the same ... after you system has 'settled in' ... regarding both platforms ... in other words ... I suspect similiar behavior would happen if it was a brand new Windows OS laptop instead of an OSX one.

BTW -- are you using OSX versions of your software ... or are you using something like Parallel's or VMWare or VirtualBox to run Windows OS

Best of luck