Can Late 2012 Mac Mini support two QHD Monitors? I've always understood that my Mac Mini is limited to one QHD (2560 x 1440/1600) monitor via DisplayPort and one HD monitor (1900x1200) via HDMI... from Wikipedia:


  Like the 2009 version, a Mini DisplayPort (which allows for a VGA
  connection, via a non-included cable) is included. A HDMI port, which
  Apple describes as being HDMI 1.4 compliant, replaces the Mini-DVI
  port on the prior models as one of the main video connection methods.
  The HDMI port supports up to 1080p on HDMI connections and 8 channel
  24-bit audio at 192 kHz, Dolby Surround 5.1 and stereo output. With
  the included HDMI to DVI adapter, for those currently using a DVI
  interface, the HDMI port will work with resolutions up to 1920 × 1200
  pixels, while the Mini DisplayPort can concurrently support a
  resolution up to 2560 × 1600 pixels


However this link suggests I can run two QHD monitors via the thunderbolt port and a splitter:


  Thunderbolt digital video output
  
  
  Native Mini DisplayPort output
  DVI output using Mini DisplayPort to    DVI Adapter (sold separately)
  VGA output using Mini DisplayPort to    VGA Adapter (sold separately)
  Dual-link DVI output using Mini    DisplayPort to Dual-Link DVI Adapter (sold separately)
  
  
  HDMI video output
  
  
  Support for 1080p resolution at up to 60Hz
  DVI output using HDMI to DVI Adapter (sold separately)
  


There is a lot of talk of DVI here, but my monitor only supports [Mini]DisplayPort and HDMI.

Am I right to read this that my Mac will support two QHD monitors but only by splitting from the DP/thunderbolt port leaving HDMI-out unused? In which case can I get a Thunderbolt->dual DP or DP->Dual DP adapter or do I have to get a DVI splitter and two DVI->DP adapters?!
Am I right to read this that my Mac will support two QHD monitors but
only by splitting from the DP/thunderbolt port leaving HDMI-out
unused? In which case can I get a Thunderbolt-&gt;dual DP or DP-&gt;Dual DP
adapter or do I have to get a DVI splitter and two DVI-&gt;DP adapters?!

There's no such thing as a Thunderbolt &quot;splitter.&quot;
You are confusing the term dual-link DVI with dual DVI.  Dual-link DVI refers to the number of data channels (double) that is available for more bandwidth meaning higher resolution.  It's not a &quot;second connection&quot; and you cannot &quot;split&quot; the signals.  Dual DVI is two DVI ports for multiple monitors.  The Mac mini does not nor support dual DVI
Multiple Monitors on a Mac mini
The Mac mini will natively support two monitors:

Thunderbolt/DisplayPort - Quad HD (2560x1600)
HDMI Port - Full HD (1080p)

To get another display or dual QHD displays, you need an additional adapter and for the Mac mini, that means USB:

USB 3.0 to DisplayPort -  Ultra HD
USB 3.0 to HDMI  - Ultra HD

This will give you another USB adapter, but be aware that you are now offloading all of the graphics processing onto the USB bus and ultimately on the CPU.  In other words, this is not something for performance, but rather convenience.  The Mac mini wasn't designed for this type of setup.