Configuring a new Mac

[Thom Hogan]

This forum gets a lot of configuration questions for new Macs. Usually that's specific to CPU/RAM/SSD choices. I'd like to point out something else everyone buying a new Mac needs to take into account: overall configuration and how the bandwidth gets distributed. Let me start with a graphic, then explain:



This is a quick example of something I'm configuring for someone. The critical aspect here is to make sure that the overall configuration works. You only have so many ports, and they can only handle so much bandwidth, so you need to consider what connects to what and why. Here I use colors to show how they connect. (Technically, the keyboard and mouse are usually connected via Bluetooth, but I show them as USB because they need charging sometimes [it's also possible that they charge from the display, depending upon what it is and how it's connected]).

The current Mac Mini has either two or four Thunderbolt ports (blue) and two USB ports (green). Note that I've defined five Thunderbolt devices and five USB ones, so they can't all directly connect to the Mini. It's possible to hook the second display to the Mini via HDMI, and that's one of the reasons why I put together this diagram, because I'm trying to balance bandwidth/connection loads. Both the OWC MiniSTX and Satechi are hubs, which can take their bandwidth and either pass it through or split it out. The Orico is just a "bunch of disks in a box"; it can pass through, but I'd be worried that all the drives in it could eat pass-through bandwidth.

Is this the best possible configuration for the user? I don't know yet, I'm still exploring how I think this is going to work for them. Note that I haven't defined yet how much internal memory or SSD is necessary, but I do know that they have about 100GB in apps and 500GB in documents on their current main drive, so I'm guessing 2TB for the SSD if they want to keep apps/docs in the box (they do).

What I keep finding working with new Mac buyers is that they don't do this sort of contemplation up front, and then they discover they need to add more things and they don't have the bandwidth for it. For instance, the illustrated system pretty much maxes out the 2 Thunderbolt Mac Mini. So much so that I'd move the 2nd display to HDMI out of the Mini box directly.

--
Thom Hogan
author, Complete Guides to Nikon bodies
bythom.com dslrbodies.com sansmirror.com zsystemuser.com

 

[Zeee]

Thanks. I’ll bookmark this. I’ll be replacing my 2019 iMac Intel within the next 12 months.

 

[mujana]

Thanks. I’ll bookmark this. I’ll be replacing my 2019 iMac Intel within the next 12 months.

 

[Thom Hogan]

Thanks. I’ll bookmark this. I’ll be replacing my 2019 iMac Intel within the next 12 months.

Same here…need ports for 2 displays (maybe Mac Studio Display and certainly my current Eizo 2700S…both USB-C) / 2 printers / external HD…maybe SSD in future / card reader

Display bandwidth can chew through PCIe lanes that are being used for other things simultaneously. That's the whole reason why I'm looking at balancing what attaches where for this person.

In my current personal system, I've daisy-chained out the drives, and I see some performance degradation at times due to all the sharing. Fortunately, that doesn't really impact what the external drives are doing, as it's either backup or more archival type storage; I've got an 8TB SSD internally, so plenty of room for things that I'm working on directly. When I next upgrade my own system I'm going to have to revisit this decision, as Apple's 8TB internal SSD pricing is pretty steep.

I really do wish Apple would make a 27" (or maybe 30") iMac with Apple Silicon. Cabling alone is like a spiderweb behind Macs these days, so every cable we can avoid makes that mess more manageable.

 

[mujana]

Thanks. I’ll bookmark this. I’ll be replacing my 2019 iMac Intel within the next 12 months.

Same here…need ports for 2 displays (maybe Mac Studio Display and certainly my current Eizo 2700S…both USB-C) / 2 printers / external HD…maybe SSD in future / card reader

Display bandwidth can chew through PCIe lanes that are being used for other things simultaneously. That's the whole reason why I'm looking at balancing what attaches where for this person.

In my current personal system, I've daisy-chained out the drives, and I see some performance degradation at times due to all the sharing. Fortunately, that doesn't really impact what the external drives are doing, as it's either backup or more archival type storage; I've got an 8TB SSD internally, so plenty of room for things that I'm working on directly. When I next upgrade my own system I'm going to have to revisit this decision, as Apple's 8TB internal SSD pricing is pretty steep.

I really do wish Apple would make a 27" (or maybe 30") iMac with Apple Silicon. Cabling alone is like a spiderweb behind Macs these days, so every cable we can avoid makes that mess more manageable.

 

[Zeee]

Thanks. I’ll bookmark this. I’ll be replacing my 2019 iMac Intel within the next 12 months.

Same here…need ports for 2 displays (maybe Mac Studio Display and certainly my current Eizo 2700S…both USB-C) / 2 printers / external HD…maybe SSD in future / card reader

Display bandwidth can chew through PCIe lanes that are being used for other things simultaneously. That's the whole reason why I'm looking at balancing what attaches where for this person.

In my current personal system, I've daisy-chained out the drives, and I see some performance degradation at times due to all the sharing. Fortunately, that doesn't really impact what the external drives are doing, as it's either backup or more archival type storage; I've got an 8TB SSD internally, so plenty of room for things that I'm working on directly. When I next upgrade my own system I'm going to have to revisit this decision, as Apple's 8TB internal SSD pricing is pretty steep.

I bet. I have gone with 512GB for my iMacs and 256GB for my MacBook air and neither is ahold full. All files on external spinners until powered SSD 6 to 8TB come down in price.

I put my money into the fastest processor I can afford and plenty of RAM for AI apps.

I really do wish Apple would make a 27" (or maybe 30") iMac with Apple Silicon. Cabling alone is like a spiderweb behind Macs these days, so every cable we can avoid makes that mess more manageable.

That has really thrown me into a loop. I may keep my 27" 5K, get a mini or studio and this but I have not investigated it thoroughly.

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[dmanthree]

My solution for connecting multiple devices to my Macbook was an Ivanky dock. It uses two firewire ports, has two firewire processors, and has plenty of ports. It's worth a look. Mine has been working perfectly since I installed it.

 

[MarshallG]

Thom, maybe I can help. I spent a decade and a half developing interface IC’s, so I am pretty familiar with their needs.

EACH Thunderbolt port on a Mac delivers an independent 40 gbps of bandwidth. It’s nearly impossible to use up all of that bandwidth except for displays. So I suggest you look at your diagram in terms of bandwidth, especially display bandwidth. It’s also very important to understand how a Thunderbolt hub apportions its bandwidth. A TB4 hub allocates the 40 gbps differently than a TB3 hub, so sometimes the TB3 hub is better.

DisplayPort uses bandwidth more efficiently than HDMI. This is because HDMI was set up around broadcast timings — they took 480i NTSC and basically doubled and quadrupled it. Great for compatibility, and it doesn’t matter much when you connect a Blu-ray to a TV, but when the bandwidth gets really high and you’re sharing it over a bus, it adds up a lot. The reason is the horizontal blanking time. As the horizontal lines get longer, the blanking period gets longer with HDMI, using up a lot of bandwidth. DisplayPort does not.

A 4K HDMI 2.0 stream is 17.82gbps, while the same stream in DisplayPort is around 15gbps. What’s worse is HDMI 2.0 maxes out at 4K60 4:4:4 8-bit, while DP 1.2 could deliver 4K60 4:4:4 10-bit with 17.2 gbps… and today, that matters a LOT. Yes, there’s HDMI 2.1 and newer DP versions which are faster, but most 4K60 displays peak at these two resolutions, so DP will give you the 10-bit video with about 17gbps, while the HDMI won’t. And, even if 4K60 8-bit is acceptable, there are many cheap hubs which claim HDMI 4K60, but they cut costs and deliver half the bandwidth, and output just 4K60 4:2:0, which is really bad for computer graphics.

Unfortunately, most manufacturers don’t tell you what their HDMI and DP supported modes are. If you’re setting up 4K60 monitors, unless the spec is clear, assume the HDMI will top out at 4K60 8-bit, which (I think) is no good for photo editing. The reason is that the added cost of the HDMI 2.1, to add that little extra oomph… is quite high. But if it’s an HDMI 4K120 screen, then of course the oomph will be there and it will have HDMI 2.1… provided that the hub you’re using converts the Thunderbolt to HDMI 2.1… which is uncommon. You need to check carefully with the manufacturer.

Long story short: Make sure the Mac model itself natively supports the number of monitors you want, then account for the Mac video resolutions of the displays and their bandwidth. As I said, 4K60 10-bit display port is about 17.2 gbps, so two of those displays will fully saturate one Thunderbolt connection, unless it enables link compression, which photographers and video editors probably won’t want.

I hope this is helpful.

 

[MarshallG]

With the current Mac Minis, the HDMI port provides only 4K60, 8-bit video unless you have the model with the M2 Pro chip, which delivers a range of HDMI 2.1 modes up to 8K60. So the 2-port Mac Mini is a bit limiting for driving a 4K HDMI monitor for photo editing.

 

[CAcreeks]

Thom, maybe I can help. I spent a decade and a half developing interface IC’s, so I am pretty familiar with their needs...

DisplayPort uses bandwidth more efficiently than HDMI. This is because HDMI was set up around broadcast timings — they took 480i NTSC and basically doubled and quadrupled it. Great for compatibility, and it doesn’t matter much when you connect a Blu-ray to a TV, but when the bandwidth gets really high and you’re sharing it over a bus, it adds up a lot. The reason is the horizontal blanking time. As the horizontal lines get longer, the blanking period gets longer with HDMI, using up a lot of bandwidth. DisplayPort does not.

A 4K HDMI 2.0 stream is 17.82gbps, while the same stream in DisplayPort is around 15gbps. What’s worse is HDMI 2.0 maxes out at 4K60 4:4:4 8-bit, while DP 1.2 could deliver 4K60 4:4:4 10-bit with 17.2 gbps… and today, that matters a LOT...

I hope this is helpful.

It was, thanks.

Do you have any numbers comparing the relative efficiency of HDMI protocol over USB-C or Thunderbolt, versus DisplayPort protocol over USB-C or Thunderbolt?

I bought a USB-C (Thunderbolt capable) to HDMI cable for connecting my monitor, but the monitor also has a DisplayPort connector. This is with the 2019 Macbook 16, which has no HDMI port, only 4 USB-C Thunderbolt ports, one of which must be used for charging. (Newer Macbooks have HDMI port and MagSafe charging.)

 

[MarshallG]

Thom, maybe I can help. I spent a decade and a half developing interface IC’s, so I am pretty familiar with their needs...

DisplayPort uses bandwidth more efficiently than HDMI. This is because HDMI was set up around broadcast timings — they took 480i NTSC and basically doubled and quadrupled it. Great for compatibility, and it doesn’t matter much when you connect a Blu-ray to a TV, but when the bandwidth gets really high and you’re sharing it over a bus, it adds up a lot. The reason is the horizontal blanking time. As the horizontal lines get longer, the blanking period gets longer with HDMI, using up a lot of bandwidth. DisplayPort does not.

A 4K HDMI 2.0 stream is 17.82gbps, while the same stream in DisplayPort is around 15gbps. What’s worse is HDMI 2.0 maxes out at 4K60 4:4:4 8-bit, while DP 1.2 could deliver 4K60 4:4:4 10-bit with 17.2 gbps… and today, that matters a LOT...

I hope this is helpful.

It was, thanks.

Do you have any numbers comparing the relative efficiency of HDMI protocol over USB-C or Thunderbolt, versus DisplayPort protocol over USB-C or Thunderbolt?

I bought a USB-C (Thunderbolt capable) to HDMI cable for connecting my monitor, but the monitor also has a DisplayPort connector. This is with the 2019 Macbook 16, which has no HDMI port, only 4 USB-C Thunderbolt ports, one of which must be used for charging. (Newer Macbooks have HDMI port and MagSafe charging.)

DisplayPort will be more efficient and you may get 10-bit color instead of just 8-bit color with HDMI; depending on the monitor.



It may seem that I prefer DisplayPort, but I don’t. HDMI has its place in this ecosystem — if you want to drive a really large display, for a kiosk or public display, HDMI is far easier to deal with. For attaching to any TV set, HDMI is the only solution. And if you deliver PowerPoint presentations; nearly all projectors and large displays use HDMI, and having the HDMI connector on the MacBook Pro is WAY better than remembering a dongle and subsequently forgetting the dongle after you deliver your slides.