I Asked Grok This Mac Hardware-Specific Question
I Asked Grok This Mac Hardware-Specific Question
I asked Grok, on X.com, this Mac hardware-specific question:
"On the late 2013 mac pro, are some of the thunderbolt ports more video display specific, like the last two ports that are on Thunderbolt Bus 0?"
…and this is the AI response that I received:
"On the Late 2013 Mac Pro, the Thunderbolt ports are not inherently "more video display specific" based solely on their position or the Thunderbolt bus they’re assigned to. However, their configuration and the way they share bandwidth can influence how they’re best used for video displays or other high-bandwidth tasks.
The Late 2013 Mac Pro has six Thunderbolt 2 ports, organized across three separate Thunderbolt buses:
- Thunderbolt Bus 0: Controls the bottom two Thunderbolt ports (ports 5 and 6) and the HDMI port.
- Thunderbolt Bus 1: Controls the top-left and middle-left Thunderbolt ports (ports 1 and 3).
- Thunderbolt Bus 2: Controls the top-right and middle-right Thunderbolt ports (ports 2 and 4).
Each bus has its own dedicated bandwidth (up to 20 Gbps with Thunderbolt 2), meaning the ports on a given bus share that bandwidth, but the buses don’t compete with each other. The key detail for video displays is that the HDMI port shares Thunderbolt Bus 0 with the bottom two Thunderbolt ports (ports 5 and 6). Since video output—whether through Thunderbolt or HDMI—relies on the Mac Pro’s GPU, and the HDMI port is tied to Bus 0, this bus can become a bottleneck if you’re using an HDMI display alongside Thunderbolt devices on ports 5 or 6.
For example, if you connect a high-resolution display (like a 4K monitor) via HDMI, it will consume a significant portion of Bus 0’s bandwidth. Adding a Thunderbolt display or another high-bandwidth device (like a storage array) to ports 5 or 6 could lead to reduced performance for either the display or the device, as they’d be sharing that 20 Gbps limit. In contrast, the ports on Bus 1 (ports 1 and 3) and Bus 2 (ports 2 and 4) are free from this HDMI-related contention, making them potentially better suited for additional displays or devices if you’re already using HDMI.
That said, all six Thunderbolt ports are fully capable of driving Thunderbolt displays or other video outputs (via adapters like Thunderbolt to DisplayPort or HDMI), as the GPU routes display signals to any of these ports. Apple’s design supports up to six Thunderbolt displays across these ports, with a maximum of two displays per bus recommended to avoid bandwidth saturation. The distinction with Bus 0 arises only because of the HDMI port’s presence, not because ports 5 and 6 are inherently more "video display specific."
So, to your question: the last two ports (ports 5 and 6 on Thunderbolt Bus 0) aren’t more video-specific by design, but their shared bus with the HDMI port means they’re more likely to be affected by video-related bandwidth demands if you’re using HDMI output. If you’re prioritizing video displays and using HDMI, you might prefer to connect Thunderbolt displays to ports on Bus 1 or Bus 2 to avoid overloading Bus 0. Conversely, if you’re not using HDMI, ports 5 and 6 are just as capable for video as any other port. It’s more about managing bandwidth across the buses than any port being specialized for video."
