Sorry if this is off-topic or just a dumb question. I've got a Mac Pro with plenty of free Thunderbolt ports, but I'm using all the USB ports - are there any Thunderbolt external DVD drives available - I've been googling for about an hour but only found one really expensive Sonnet drive - which has way more functionality than I need.
You won't find a Thunderbolt 1 (much less and Thunderbolt 2/3) to an external DVD drive because there simply isn't any need to create one as USB 2.0 has more than enough bandwidth to accommodate even the fastest DVD drives on the market.
To understand why, we have to understand that the fastest DVD you will find is a 24x unit; most will be 16x. The base write speed is 1x and a 1x speed is 1.32Mb/s so a 24x unit is about 31Mb/s.1
USB 2.0's transfer speed is 280Mb/s or about 35MB/s 2 so even the theoretical fastest DVD drive that you will ever find is less than the max limit of a USB 2.0 connection which, for all intents and purposes, has been obsolete since the beginning of 2009 (USB 3.0).3
There just isn't a need to create a DVD drive with a modern, high speed data transfer interconnect because it's a dying technology and it's fastest transfer rate doesn't even begin to exceed what is already backwards compatible with USB 3.0
1 Wikipedia Modern compact discs support a writing speed of 52X and higher, with some modern DVDs supporting speeds of 16X...
2 Wikipedia USB 2.0 was released in April 2000, adding a higher maximum signaling rate of 480 Mbit/s (High Speed or High Bandwidth), in addition to the USB 1.x Full Speed signaling rate of 12 Mbit/s. Due to bus access constraints, the effective throughput of the High Speed signaling rate is limited to 280 Mbit/s or 35 MB/s.
3 Wikipedia The USB 3.0 Promoter Group announced on 17 November 2008 that the specification of version 3.0 had been completed...
You might want to take a look at Sonnet Technologies Thunderbolt 2 Docks:
Echo 15+ Thunderbolt 2 Dock (with Blu-ray Burner) - $499
Echo 15+ Thunderbolt 2 Dock (with DVD±RW Drive) - $349
A bit pricy, but a crap-ton of ports.
(From the Sonnet site:)
• Connects Your Peripherals with One Cable—Connect your peripherals to the Echo dock; connect your computer to and disconnect it from the dock using one Thunderbolt cable
• Provides Multiple Interfaces—Thunderbolt 2, USB 3.0, 6Gb/s SATA and eSATA, FireWire 800, Gigabit Ethernet, and audio
• Adds a DVD±RW Drive to Your Computer—Includes an 8x DVD±RW drive to load software, import CDs, burn CDs and DVD-ROMs, and play DVDs
• Supports Internal Hard Drive or SSD Installation—Install one 3.5" hard drive, or two 2.5" SSDs or hard drives inside the dock
• iOS Device Charger—USB 3.0 ports can charge your iPad, iPhone, or iPod, even while the computer is disconnected, off, or sleeping; all four ports provide 7.5W, optimized for quick charging
• Wide Range of Display Connection Options—Select from a variety of inexpensive Mini DisplayPort to popular display interfaces such as HDMI, DVI, VGA and Dual-Link DVI
• Compatible with Every Thunderbolt Mac—Supports any Mac with a Thunderbolt port running OS X 10.9.5+
Disclaimer - I have no financial stake in Sonnet Technologies, and I have neither used nor tested any of these Docks. Sonnet has been around for many years and is a reliable company.