• Mac Pro (Late 2013): Recommended software and firmware updates
  (archived Dec 2016)
  
  
• Mac Pro (Late 2013): Using multiple displays (archived Dec 2019)
• Mac Pro (all models): Graphics card compatibility between models
  
  
• Mac Pro (Late 2013): Removing and installing flash storage (archived Sept 2020)
  
  
• Mac Pro (Late 2013): Memory specifications (now goes to Tech Specs)
• Mac Pro (Late 2013): Installing or replacing memory (archived June 2021)
  
  
• Using the Mac Pro (Late 2013) on its side (archived Jan 2017)
• Mac Pro (Late 2013): External features, ports, and connectors (archived Jan 2017)
• Mac Pro (Late 2013): Issues connecting a Thunderbolt device to another Thunderbolt device (archived March 2018)
  
  
• Mac Pro (Late 2013): Audio ports (archived Jan 2017)
• Mac Pro (Late 2013): Audio from game might stop after wake from sleep (Line Out)
  - Article HT203874 (originally TS5309) no longer online.
  
  
• Mac Pro (Late 2013): Recovering a lost firmware password
  now goes to Set a firmware password on your Mac
  
  
• Mac Pro (Late 2013): How to find the serial number
  now goes to Identify your Mac Pro model
  
  
• Mac Pro: Power consumption and thermal output (BTU/h) information
  - article includes info on all Mac Pro models/years.
  
  Boot Camp/Windows Related:
• Mac Pro (Late 2013): Might not wake from sleep in Windows 8 (archived Dec 2016)
• Mac Pro (Late 2013): Using multiple displays with Windows (archived Dec 2019)
• Boot Camp: Installing Windows 7 Frequently Asked Questions (archived Sept 2018)
  (64bit Windows only for 2013 Mac Pro)

If you missed it yesterday, the Dec. 19, 2013 news had info/download on the EFI Firmware Update 2.0 for Late 2013 Mac Pros and an OS X 10.9.1 Updater for Late 2013 Mac Pros.
 

How-To Video on 2013 Mac Pro CPU Upgrade: (Jan. 2014)
OWC's 2013 Mac Pro upgrade videos had a Step-by-Step Video on 2013 Mac Pro CPU Upgrades. Video is available in 3 sizes. (An old tip for applying thermal paste was to use a sandwich baggie over your finger - keeps skin oils off the surfaces and your hands clean.)
(April 2014 Update: They now offer a Turnkey CPU Upgrade Service for Late 2013 Mac Pros.)

2013 Mac Pro Internal SSD Upgrades (1TB to 4TB) (updated Jan. 2016)
OWC had Late 2013 Mac Pro SSD Upgrades of 1TB, 2TB, and 4TB. (Page noted these include a USB 3.0 External Case to reuse the original 2013 Mac Pro SSD/flash drive.)

2013 Mac Pro and USB 3.0 Hubs:
Not sure how many this affects (as there's been issues with some USB 3.0 hubs with other Macs), but a reader asked I post a FYI on an issue booting a new Mac Pro (Late 2013) if a USB 3.0 Hub was connected at powerup. His notes on tests with two USB 3.0 hubs are in this Apple forum thread on New Mac Pro (late 2013) USB 3.0 hub issue during boot. However later replies in that thread from other Late 2013 Mac Pro owners said they've not seen any issues with USB 3.0 hubs, including one owner using the same hub model.
 

• (Short) 2013 Mac Pro review (t3)
  
  
• Apple Mac Pro 2013: in pictures (digitalartsonline)
  
  
• The First Apple-Certified iOS Gaming Controllers Need a Power-Up (wired)

• About the transition to Compressor 4.1 white paper
• MainStage 3: Troubleshooting basics
  - now titled "If MainStage isn't working".
  
  
• Using 4K Ultra HD TVs with Mac computers
  now goes to Connect a display to your Mac
• Using USB 3 devices on Mac computers FAQ
  now goes to Identify the ports on your Mac
  
  
• Apple Thunderbolt cables and adapters
  now goes to Adapters for the Thunderbolt 4, Thunderbolt 3, or USB-C port on your Mac
• Thunderbolt ports and displays: Frequently asked questions (FAQ)
  now goes to Adapters for the Thunderbolt 4, Thunderbolt 3, or USB-C port on your Mac
  
  
• iMac (Late 2013): Understanding the first startup cycle (article no longer online)
• Get help with the slot-loading SuperDrive on your Mac computer (archived Dec 2020)
• If your external display isn't detected or appears blurry when connected to your Mac
• Macs with Fusion drive: How to find BOOTCAMP partition in Windows installer (archived July 2020)
  
  
• Identify your Mac Pro model
• Mac Pro (Early 2009) RAID Card: Identification and compatibility (archived Dec 2016)
• Mac Pro (Mid 2012 and earlier): Frequently Asked Questions about the Mac Pro RAID Card and Xserve RAID Card (archived June 2017)
  
  
• Mac Pro (Mid 2010 and Mid 2012): Migration does not complete (archived March 2019)
• Mac Pro (Mid 2012 and earlier): How to remove or install memory (archived Sept 2020)
• Mac Pro (Early 2009 through Mid 2012): Audio may not switch when new devices are connected (archived Jan 2017)
  
  
• Use AirPlay to stream video or mirror the screen of your iPhone, iPad, or iPod touch
• Update your iPhone, iPad, or iPod touch
• If you can't update or restore your iPhone or iPod touch
• Wireless carrier support and features for iPhone in the United States and Canada
  
  
• Find an iTunes or Finder error code
  - was titled "iTunes: Possible iTunes Store errors".
• Resolve issues between iCloud for Windows or iTunes and third-party security software
  
  
• System requirements to install Windows using Boot Camp for macOS
  
  (The Following Docs were Archived, but now No Longer Online)
• Mac Pro (Early 2008 to Mid 2012): About the PCI Express slots (HT2838)
• Power Mac G5 and Mac Pro (Mid 2012 and earlier): How to open the CD/DVD tray (HT2575)
• Mac Pro (Mid 2012 & earlier): Graphics card video compatibility with Apple DVI-to-video adapter (HT2809)