The T-Mobile version of Galaxy S 4 isn't the only flavor of Samsung's new flagship that's getting updated today, as it appears that the AT&T variant is also being treated to some new software. PhoneDog reader Mitchell just let us know that the AT&T Galaxy S 4 is receiving a 21.39MB update over the air that he says has eliminated the lag that he was experiencing on his device. Neither AT&T nor Samsung have posted any details on the update, but several XDA-developers forumgoers also report having received an update, which they say bumped the device up to baseband version I337UCUAMDL (the AT&T Galaxy S 4 launched on baseband version I337UCUAMDB).

As for what's inside the update, well, that much is still a mystery for now. Several AT&T Galaxy S 4 owners feel that their device is much less laggy after the update, and it's also said that the update brings with it an updated kernel. There's not much else known about the I337UCUAMDL update for now, but as usual, you can bet that we'll keep an eye out for more information. If you've got an AT&T Galaxy S 4 and you want to check for the update before then, you can do so by heading into Settings > Settings > More tab > About device > Software update.

Thanks, Mitchell!

Via @madlaw1071, XDA-developers