Does anyone know if the 15" 2012 MBPR (that is, MacBookPro10,1) supports 4K with its HDMI output under Mavericks? Of course, it will only be 30Hz, but that's tolerable.
For example, every macbook pro in the last 5 or 6 years that had replaceable RAM had an actual RAM limit that was double what Apple said was its RAM limit. I wouldn't be surprised if 4K works, albeit perhaps a little sluggishly.
If you give them the option for 4Gb, 8Gb, 16Gb and 32Gb instead of limiting to 16Gb lots of people will freeze and never make a choice or get frustrated when they see the markup for 32Gb and avoid buying altogether because of that.
In limiting the amount of upgradable RAM on their sales page they show you choices that are most likely going to be easy to sell.
"Supported" is not the same thing as "it works".
You need to be running Mavericks to use its native HDMI port. I am running the default version it came with (10.7.x) so it only works on the HDMI port under linux (which I primarily use on it) and Windows. That being said I use an Accel Active DP 1.1 -> HDMI 1.4 adapter which makes it work just fine even on older version of mac os X. Actually with that adapter you can use a lot of even much older macs to drive the seiki or any other 4k 30hz display.
The adapter: http://www.amazon.com/Accell-B086B-008B-UltraAV-DisplayPort-...
I don't think the HDMI hardware is new enough in the 2012 for HDMI, though in theory display port might work if the drivers get enabled for it.
Click the Apple icon in the top left of the menu bar, choose "About This Mac", click "More Info", click "System Report", and on the first screen ("Hardware Overview"), the Model Identifier will be displayed. Mine is "MacBookPro10,1".
I would love to verify that it is capable of driving these 4k displays, if you wouldn't mind checking.