The screen ( UP2715K) is driven by the same graphics card.... Would it be better to drive this monitor through thunderbolt ports from the"same" bus or would it be better using different bus thunderbolt ports.
Hypothetically .....
Using two separate buses may allow for a faster flow of data (?) -would using the same thunderbolt ports of the same bus allow for more "efficiency" for the system in the flow on data?
Insight appreciated :)
Mac Pro, macOS 15.3
This is great information !! Then it shall be so - will place both DP cables on the same bus in the back of this beautiful MacPro for the 5k .
Thank you for the insight. How data is managed is so very intriguing. Amazing engineers and programers :)
<<Using two separate buses may allow for a faster flow of data (?). >>
No, that is not correct.
Once the data has been placed in the display buffer, the RE-draw of display data is such a minuscule processor load, it is not even measurable. And since the Video RAM is right on the display card, fetching that data does not compete with instruction and operand fetching from main RAM memory.
The data rates for displays are the Fastest and most unrelenting data stream on an integrated-display computer like these Macs. But these data rates are already WAY too fast for the processors to handle every byte. Instead the processor's job is the set up a Hardware Automaton, the display-generator, whose job it is is to get the display data out of the display memory, and send it out to the display, then ask for more, about sixty times a second or more.
Your MacPro can handle only a limited number of displays. That number is limited by the number of display-generator automata inside your specific MacPro -- Six. And they are ALL on ONE of the cards, and there are no others on the other card.
Your initial block diagram suggested that you were considering hooking up to the two different display cards. But what Apple calls the "A" card has no display attachment hardware.
When multiple displays are competing for the same bandwidth, AND you are getting near the limits of multiple displays on one ThunderBolt Bus, it can give slightly better results using two Thunderbolt ports on different busses. But there is no need to work very hard at it, and it will not make a huge difference in ... anything.
When this becomes important is when you are also hooking up additional High-Speed devices, such as external drives. In that case you want to distribute those drives away from displays when possible, because a display can use up most of the bandwidth on a thunderbolt Bus.
Very kind of you to reply.....truly do not have a complicated setup what so ever :) It's just one 5K screen with dual display port input requirement ( coming from two thunderbolt 2 outputs ) ...... to your point -I don't think it will make much of tabgible difference where the inputs come from it seems - this was an academic exercise :)
5K Dual DP to Mac Pro 2013
