After releasing iOS version 6.0.2 to fix issues with Wi-Fi on the iPhone 5 and the iPad mini, Apple today seeded build 12D43 of OS X 10.8.3 Mountain Lion to developers.
mountainlionbetaupdateThough the update comes with no known issues or new features, Apple has asked developers to focus on AirPlay, AirPort, Game Center, Graphics Drivers, and Safari in their testing.

This is the third beta release since the first 10.8.3 beta was seeded back in November. Registered developers can download it via the Apple Developer Page.

Update: 9to5Mac reports that Apple has now released build 12D44 to developers, some two days after 12D43 was released. This release still reports no known issues, though it's possible the quick update is a fix for some unmentioned bug.

Top Rated Comments

3282868 Avatar
169 months ago
This is pretty sad. Apple has moved to an annual release cycle for OS X, placing 10.9 not too far into the near future, and 10.8 is still giving a good amount of users grief.

Some prominent bugs for many:

- WiFi connectivity since 10.7
- The "Chris Angel" disappearing mouse cursors
- Graphic glitches (static images in many core apps)
- Slower system functionality compared to 10.6 even with more RAM
- SMB and file sharing protocol nightmares
- An antiquated HFS+ Finder (even ZFS would have been much better, which has been discussed at great length since 10.5 beta's)
- Less configuration options with such OS X utilities as AirPort Utility 6.0 (thankfully I can drag and drop 5.x as it will not install in 10.8)
- OpenGL Core way behind other systems
- iWork '09 and iLife '11 are barely updated save for iOS "features"
- Axed Keychain and Dock syncing bet Mac's, and iDisk (shame Dropbox wasn't acquired)
- Axed web hosting
- OS X Server became a cheaper app addition and lacks important aspects that 10.6-7 Server offered
- Oh look, more social networking thrown into every core app. Yeah.

You'd believe all these dropped components would give Apple engineers more time to focus on producing a polished system as previous years have shown. Ironic.

God I miss the days before 10.7. Bring back Bertrand Serlet!
Score: 5 Votes (Like | Disagree)
lcmazza Avatar
169 months ago
Coming back from sleep is still terrible on rMBP... USB becomes sluggish, external keyboard doesn't wake up the system...

Graphics switching is still pretty bad. :(
Score: 4 Votes (Like | Disagree)
Prof. Avatar
169 months ago
Here's hoping it fixes the slow shutdown times. :(
Score: 4 Votes (Like | Disagree)
sshhoott Avatar
168 months ago
Mac mini (mid-2010) with the 320M

12D44 working good so far!
I am so disappointed in Apple about their handling of Nvidia 320M, this is on a Macbook Pro 13" mid 2010. The animations get choppy as heck just after a few hours of usage, such as changing desktop animation. I tried the same thing on the Macbook Pro 13" 2009 (Nvidia 9400M), but it stays smooth. To make matters worse, I experience enournous amounts of memory leak in the form of inactive memory, which never clears unless I restart. I have done clean installations of OS X 10.8.2.

Some say they resort to this method: //www.youtube.com/watch?v=gmoWoeNrkOs to achieve smoothness.

But this shouldn't be happening to a computer like Mac where the weaker one outperforms the stronger one :mad:. What are your guys thoughts? Have you had similar issues with 320M?

Any developers reading this post, please notify Apple about these "bugs" concerning Nvidia 320M. Would extremely appreciate it.
Score: 2 Votes (Like | Disagree)
JGRE Avatar
169 months ago
What i really liked about OS X before Lion and Mountain Lion that shutdown was very much instant (at least for me).

Now it seems all kinds of crappy services have taken the stage and all the Snow Leopard optimisation has taken the backstage.
Right, now it feels if you are working on a Windows computer.........:eek:

Is it just me, or does opening the systems settings window take far more time then it did under 10.7?
Score: 2 Votes (Like | Disagree)
mag01 Avatar
169 months ago
This is pretty sad. Apple has moved to an annual release cycle for OS X, placing 10.9 not too far into the near future, and 10.8 is still giving a good amount of users grief.
...
God I miss the days before 10.7. Bring back Bertrand Serlet!

Agreed.
Though as for ZFS I don't like it much for its memory requirements - it's more suitable for server environments. Though there are ways how to scale the RAM usage down (more or less).
Score: 2 Votes (Like | Disagree)

Popular Stories

Apple Shopping Event 2025

Apple Announces 2025 Black Friday Event, Here's What You Can Get

Thursday November 20, 2025 6:28 am PST by
Apple's annual four-day Black Friday through Cyber Monday shopping event is returning on Friday, November 28 through Monday, December 1 in many countries, including the United States, Canada, Australia, New Zealand, France, Germany, Italy, Spain, the United Kingdom, Belgium, the Netherlands, Sweden, Thailand, and others. During the shopping event, customers can get an Apple gift card with...
iPhone 17 Pro Cosmic Orange

10 Reasons to Wait for Next Year's iPhone 18 Pro

Wednesday November 19, 2025 4:00 am PST by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models at the same time, which is why we often get rumored features months ahead of launch. The iPhone 18 series is no different, and we already have a good idea of what to expect for the iPhone 18 Pro and iPhone 18 Pro Max. One thing worth...
iOS 26

Everything New in iOS 26.2 Beta 3

Monday November 17, 2025 3:20 pm PST by
Apple provided developers with the third beta of an upcoming iOS 26.2 update, and there are still new features that are being added with each beta that we get. We've rounded up all of the changes that Apple made in beta 3. AirDrop Apple added new AirDrop functionality, providing a way for two people to share files temporarily without having to add one another as contacts. iOS 26.2...
applecare apple care banner

Apple Brings New AppleCare+ Options to India

Tuesday November 18, 2025 8:42 am PST by
Apple today announced an expansion of AppleCare+ coverage in India, with new options for monthly and annual plans, and the addition of Theft and Loss for iPhone for the first time. Options for monthly and annual AppleCare+ plans in India provide more choice and flexibility, allowing users to keep coverage for as long as they require. Apple's vice president of Worldwide iPhone Product...
ipad mini 7 feature red and blue

iPad Mini 8: Four Major New Features to Expect

Wednesday November 19, 2025 7:50 am PST by
Apple's eighth-generation iPad mini is highly likely to arrive next year, offering a significant refresh of the device with at least four major new features. OLED Display The next-generation version of the iPad mini could feature an OLED display, as part of Apple's plan to expand the display technology across many more of its devices. Apple's first OLED device was the Apple Watch in 2015, ...
iPhone 17 Pro and Air N1 Feature

iPhone 17 vs. iPhone 16 Wi-Fi Speeds: New Study Reveals the Winner

Tuesday November 18, 2025 10:53 am PST by
A new study has revealed that the iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, and iPhone Air achieve significantly faster average Wi-Fi speeds compared to the iPhone 16 series, thanks to Apple's custom-designed N1 chip. The study was conducted by Ookla, the company behind the popular Speedtest website and app. It said the results are based on global, crowdsourced Speedtest user data...
Apple Wallet ID Illinois

iPhone Driver's License Feature Launching in Illinois

Tuesday November 18, 2025 8:47 am PST by
In select U.S. states, residents can add their driver's license or state ID to the Wallet app on the iPhone and Apple Watch, providing a convenient and contactless way to display proof of identity or age at select airports and businesses, and in select apps. Starting this Wednesday, November 19, the feature will be available to residents of Illinois. The announcement confirmed that the...
macbook black friday

The Best Early Black Friday Mac Deals

Tuesday November 18, 2025 7:32 am PST by
We're getting closer to Black Friday, which lands next week on Friday, November 28. In the lead-up to the shopping holiday, we're tracking a few lowest-ever prices on Apple's most popular Macs, including the M4 MacBook Air and brand new M5 MacBook Pro. Note: MacRumors is an affiliate partner with some of these vendors. When you click a link and make a purchase, we may receive a small payment,...
iOS 26

iOS 26.2 Adds These New Features to Your iPhone

Thursday November 20, 2025 10:50 am PST by
iOS 26.2 is currently in beta testing. The upcoming update includes a handful of new features and changes on the iPhone, including a new Liquid Glass slider for the Lock Screen's clock, offline lyrics for Apple Music, and more. In a recent press release, Apple confirmed that iOS 26.2 will be released to all users in December, but it did not provide a specific release date. Keep reading...
Magic Keyboard Touch ID Feature

Apple Releases New Firmware for 140W USB-C Power Adapter, Magic Keyboard and Magic Trackpad

Tuesday November 18, 2025 1:05 pm PST by
Apple today released updated firmware for several accessories, including the 140W USB-C Power Adapter, the Magic Trackpad 2, the Magic Trackpad USB-C, the Magic Keyboard with Touch ID, and the Magic Keyboard with Touch ID and Numeric Keypad. There is no word on what's included in the updated firmware at this time, but it could offer performance improvements and security updates. Accessory...