Early 2011 13" MacBook Pro (Intel HD Graphics 3000) driving TWO or THREE external monitors - Thunderbolt 1 awesomeness

[joevt]

So if you connected that monitor to a Mac running Sierra or High Sierra it wouldn't display properly?

Unless the 5K tiling works without the mtdd or it's hard coded in the driver.

Maybe the tiling info is hard-coded?

Maybe. I know the Nvidia driver had hard coded dual link SST support for the Dell UP2715K but not for other displays. This is discussed in hackintosh forums.

Or the Eizo FDH3601, or the IBM T221.

Right. But that might be understandable since those displays don't have tile info in their EDIDs (at least for the IBM T221 - I haven't seen the EDID for the Eizo FDH3601).
But Linux lets you create screens from multiple displays so that's no excuse.

 

[Amethyst1]

But Linux lets you create screens from multiple displays so that's no excuse.

And for Windows there's Collage Mode (Intel), Eyefinity (AMD), Mosaic or Surround (NVIDIA).

edit: An update on the tiled 1920×2160 setup: one half was showing flashing/flickering vertical red lines after rebooting or waking from sleep. It turns out that was caused by the tight CVT-RB v2 timings I used to get 60 Hz. Switching to more generous CVT-RB timings got rid of the lines, but limits the attainable refresh rate to 58 Hz. There's no discernible difference to 60 Hz to me though.

 

[joevt]

And for Windows there's Collage Mode (Intel), Eyefinity (AMD), Mosaic or Surround (NVIDIA).

edit: An update on the tiled 1920×2160 setup: one half was showing flashing/flickering vertical red lines after rebooting or waking from sleep. It turns out that was caused by the tight CVT-RB v2 timings I used to get 60 Hz. Switching to more generous CVT-RB timings got rid of the lines, but limits the attainable refresh rate to 58 Hz. There's no discernible difference to 60 Hz to me though.

Probably unrelated to this, but interesting: I noticed that for a Dell UP2414Q display (a 4K MST display), Apple has an EDID override that reduces the 4K30Hz SST mode from 300 MHz down to 262.75 MHz.

3840x2160@30.303Hz 68.182kHz 300.00MHz h(176 88 296 +) v(8 10 72 +)
3840x2160@29.981Hz 65.688kHz 262.75MHz h(48 32 80 +) v(3 5 23 -)

For the tiled modes, both tiles are:
1920x2160@59.988Hz 133.293kHz 277.25MHz h(48 32 80 +) v(3 10 49 -)

 

[Amethyst1]

Probably unrelated to this, but interesting: I noticed that for a Dell UP2414Q display (a 4K MST display), Apple has an EDID override that reduces the 4K30Hz SST mode from 300 MHz down to 262.75 MHz.

There’s also an override for the Dell UP3214Q.

 

[Amethyst1]

I had been looking at that inexpensive Thunderbolt adapter you posted recently which tricks the bus into thinking a max-size display is connected, so that accessing it with Remote Desktop or VNC will present a 2560x1600 remote display screen when in clamshell mode.

You could also look into software solutions which allow using a Mac/PC/iPad as a secondary display, if you don't want an "actual" display. These all have an impact on the CPU though.

Air Display
Duet Display
Luna Display (I've used that one; performance was OK; a bit pricey due to required dongle, I got mine off eBay)
ScreenRecycler (no longer sold; allows any VNC client to become a display)

 

[joevt]

There’s also an override for the Dell UP3214Q.

Oh yeah, I found that back in 2014. Mac OS 10.9.3 added the following:

New:

• DEL DELL UP2414Q
• DEL DELL UP3214Q
• ACI PQ321 (ASUS)
• SNY SONY TV *07

Modified:

• SHP PN-K321

These displays are mentioned in https://web.archive.org/web/20181129040631/support.apple.com/en-us/HT206587

The override for the UP3214Q is for the product id 4093 (DisplayPort) but I only have an EDID for 4092 (HDMI) from the linuxhw/EDID database (GitHub) so they can't really be compared.

 

[Amethyst1]

As Erik would say - three displays are better than two! So...

Three external displays from the 2011 13" MBP

Two daisy-chained Thunderbolt docks as usual. The one on the top is connected to the MBP via the black Thunderbolt cable and drives the original 22" Cinema Display via a HDMI-to-DVI adapter. The white Thunderbolt cable daisy-chains the second dock on the bottom - from there, a MiniDisplayPort-to-DisplayPort cable goes to a magic box:

It presents itself as a single ultrawide 3840×1080 DisplayPort monitor to the system and splits the incoming signal into two discrete 1920×1080 signals, each of them driving one monitor via DVI. This allows two monitors to be driven from one output. The MBP thinks it has two monitors attached to it while it's actually three.

Mode = 3840 × 1080 @ 60.000Hz
        Pixel Clock............. 266.64 MHz         Non-Interlaced

                                 Horizontal         Vertical
        Active.................. 3840 pixels        1080 lines
        Front Porch.............   48 pixels           3 lines
        Sync Width..............   32 pixels           5 lines
        Back Porch..............   80 pixels          23 lines
        Blanking................  160 pixels          31 lines
        Total................... 4000 pixels        1111 lines
        Scan Rate...............  66.660 kHz         60.000 Hz

        Image Size..............  255 mm             255 mm
        Border..................    0 pixels           0 lines

            Sync: Digital separate with
                * Positive vertical polarity
                * Positive horizontal polarity

 

[joevt]

It presents itself as a single ultrawide 3840×1080 DisplayPort monitor to the system and splits the incoming signal into two discrete 1920×1080 signals, each of them driving one monitor via DVI. This allows two monitors to be driven from one output. The MBP thinks it has two monitors attached to it while it's actually three.

Mode = 3840 × 1080 @ 60.000Hz
        Pixel Clock............. 266.64 MHz         Non-Interlaced

                                 Horizontal         Vertical
        Active.................. 3840 pixels        1080 lines
        Front Porch.............   48 pixels           3 lines
        Sync Width..............   32 pixels           5 lines
        Back Porch..............   80 pixels          23 lines
        Blanking................  160 pixels          31 lines
        Total................... 4000 pixels        1111 lines
        Scan Rate...............  66.660 kHz         60.000 Hz

        Image Size..............  255 mm             255 mm
        Border..................    0 pixels           0 lines

            Sync: Digital separate with
                * Positive vertical polarity
                * Positive horizontal polarity

I would like to see the EDID (hex or bin) for that Matrox DualHead2Go Digital ME . Is there a USB device in System Information.app? Is there software to control it via USB?

 

[Amethyst1]

I would like to see the EDID (hex or bin) for that Matrox DualHead2Go Digital ME .

Attached are two EDIDs as read by SwitchResX. The first only has the 2× 1920×1080 60Hz (r) mode that I've been using in it (in addition to standard timings). The second has two additional modes added to it for the fun of it.

Is there a USB device in System Information.app?

Yup.

Is there software to control it via USB?

Yup. There's an info/diag tool...

...and a tool to select up to four supported dual-monitor resolutions and add them to the box's EDID. (Resolutions that have already been added aren't listed.)

4:3 Landscape:

16:9/16:10 Landscape ['(r)' means reduced blanking and pixel clock compared to default mode]:

4:3 Portrait:

16:9/16:10 Portrait:

 

[joevt]

Attached are two EDIDs as read by SwitchResX - no AGDCDiagnose on 10.9.5. The first only has the 2× 1920×1080 60Hz (r) mode that I've been using in it (in addition to standard timings). The second has two additional modes burned into it for the fun of it.

Yup.

Yup. There's an info tool...

...and a tool to select up to four supported dual-monitor resolutions and burn them into the box's EDID. (Resolutions that have already been burned into the EDID aren't listed.)

Interesting. It's a super simple EDID that only includes the base block. Since they allow up to four supported resolutions, it means they don't reserve a descriptor for a display name which is what I noticed in your first screen shots.

 

[Amethyst1]

Since they allow up to four supported resolutions, it means they don't reserve a descriptor for a display name which is what I noticed in your first screen shots.

It was named DualHead2Go - until I added the resolution I wanted. I wonder if resetting to factory defaults will restore the name. I also noticed this while playing with an older variant of the device (post #1 vs #14).

 

[joevt]

It was named DualHead2Go - until I added the resolution I wanted. I wonder if resetting to factory defaults will restore the name. I also noticed this while playing with an older variant of the device (post #1 vs #14).

Maybe if you're not using more than 3 resolutions, then the EDID will include a name. Or you could set the name in an override file so it's always there. SwitchResX can do that for you.

 

[Amethyst1]

Maybe if you're not using more than 3 resolutions, then the EDID will include a name.

The name vanished after adding one resolution.

Or you could set the name in an override file so it's always there. SwitchResX can do that for you.

Yeah, that sounds like a plan.

 

[Amethyst1]

I have that early 2011 13-inch MBP, identical to yours, which I feel deserves more screen real estate — either literally or virtually.

I had been looking at that inexpensive Thunderbolt adapter you posted recently which tricks the bus into thinking a max-size display is connected, so that accessing it with Remote Desktop or VNC will present a 2560x1600 remote display screen when in clamshell mode.

You might not need any extra hardware after all.

So, using e.g. RetinaDisplayMenu the 2011 13-inch MBP can be set to a scaled resolution of 1920×1200 out of the box. Selecting it will downscale a 1920×1200 framebuffer to the MBP's 1280×800 LCD. This makes everything tiny and hard to see but connecting via Remote Desktop or VNC provides a perfectly usable 1920×1200 desktop. Subsequently, I used SwitchResX to define higher scaled 16:10 resolutions... Mavericks allows 2048×1280 on the HD 3000 (in line with my previous discoveries), while High Sierra allows 2432×1520.

Here's a (pretty ordinary-looking) screenshot at 2304×1440:

If you want to try this yourself, I can provide the override file to unlock higher-than-1920×1200 resolutions (and rename the display ).

It’s worth noting that downscaling does have an impact on the GPU - I mean, the poor thing has got more work to do LOL!

 

[snakesm]

This one hits a bit close to home for me, as a 2011 MBP was my first Mac and one of only two over the years I've bought new. It served me while, along side other Macs, was mostly replaced by a 2012 15"(9,1), and the latter was replaced earlier this year by an M1 Pro.

In any case, a desktop such as my maxed out 5,1 isn't a great option for me right now, but I need a computer that can run SL-natively run it and not virtualized. Of course the 2011 MBPs fit the bill for this, and the late 2011s work just fine as long as you have the 10.6.7 restore disk that shipped with the early 2011s(I have a couple, although ended up making an installer on a USB stick). I don't want to dump all the data on my MBP 8,1, but carved out a 50gb SL partition for it and it's running fine, although High Sierra is still its "main" OS so to speak.

All of that rambling aside, though, after a year of working from home(and mostly not now) I'm finally getting a home office set up, albeit while I'm waiting for a desk to arrive I'm using a 6 foot table. I bought a fancy OWC TB3 dock, which can charge my M1 along with giving me tons of useful ports and other add-ons. In testing, though, sure enough(via a TB2-TB3 adapter) it works perfectly with my 8,1 in 10.13, and gives full USB 3.0 support.

Initially I set this up with a 27" Apple Cinema, which is a monitor I still like. Back in the day, though, I always wanted a Thunderbolt display. They're the same panel as the Cinemas and really look all but identical, but of course at the time were also one of the few TB docks around. I finally broke down and bought one-they can be had for around $200 shipped on Ebay with some patience.

That made me realize that all of the above was possible-the TB display itself is a TB hub, so when it arrived today, I worked it onto my "desk"(a bit snug on space, but it fit) then hooked it to the TB3 dock by way of a TB2-TB3 adapter. For ease of set-up at the time, I then used a second TB2-TB3 into the dock from the 8,1. Sure enough, booted into High Sierra, it all came to life

View attachment 1834917 View attachment 1834919

And yes, that is the SL wallpaper on the right display. I have been known to use wallpaper from older versions of OS X because I like them, and with the pleasant side effect of annoying @LightBulbFun . The left screen has the ML wallpaper.

For now, the TB display has displaced the Cinema display on my desk, as can be seen there's really not enough room comfortably for two displays. The TB display has some nice benefits like giving me a FW port(how many people have FW on their M1 Macs?). Also the TB display bumped to a 720p "Facetime Camera" and not the 480p "iSight" of the Cinema(I've been feeling weird using Zoom with the cinema since the camera is terrible compared to the one on any of the laptops I use, but it means having to either not face the camera or have to look at the laptop screen...). Overall it's a good upgrade. I'd make two displays work if the M1 could actually drive them.

As another side-note on the dock-SL sees it, but it's completely dead. It just registers as a bunch of devices for which there aren't drivers, which isn't surprising. Unfortunately, though, I'd hoped at least the mini-DP split off would work, but it doesn't.

I do want to set this all back up, though, with my 11" MBA for maximum enjoyment

Thanks a lot for a super detailed and interesting post.
While I saw many references to the TB2-TB3 adapter I'm still reasonably confused about the use case when you want to connect TB3 dock to the old device with TB2 port.
I'm in the same boat, I do have TB3 dock station from HP which I use on daily basis with my Windows laptop and I do have iMac 2011 with TB2 port where I will be really happy to connect the dock to.

Will you be so kind to share some photos where its shown in details how do you connect this adapter both to TB display (which I kind of can guess) and especially how do you connect the adapter to TB3 dock (as mine has a lead and the adapter has TB3 mail port so... a bit puzzled)

Regards Sergiy

 

[Amethyst1]

how do you connect the adapter to TB3 dock (as mine has a lead and the adapter has TB3 mail port so... a bit puzzled)

If your TB3 dock has a non-removable TB3 cable you cannot connect it to the TB3-to-TB2 adapter.

 

[bunnspecial]

As I mentioned, I'm using the OWC 14-port TB3 dock with the TB Display.

Here's my general set up, and this is optimized(ish-I still want a longer TB1/2 cable) for easy use with either my M1 Mac or one of my older computers.

First of all, the OWC dock has two female TB3 ports in the back of it. To one of those is connected a TB3 male-male cable(looks just like a USB-C cable but more expensive) which then attaches to my M1 Pro(but could work with any TB3 Mac, or I assume any TB3 computer, easily). Out the other port is a TB2-TB3 adapter, into which the TB Display is plugged.

Now, here's one of the back of the TB display, which exploits a bit of an interesting feature

If I wanted to do so, I could connect a TB1/TB2 Mac to this whole set-up using a second TB2-TB3 adapter hanging out the hub, and I have done that.

With that said, the TB display has a second TB port on the back that can daisy-chain to a second TB display or other TB devices(there weren't a lot on the market when it came out). It's actually bi-directional, though, and if you plug a TB2 cable into the TB port on the back of the TB display then connect it to your computer, everything will still work exactly as intended.

What that means is I can leave that second TB cable dangling there, and when I want to connect a TB1 Mac, I can plug it in via that cable. If I want a second display, the dock still breaks out mini-DP so it will work.

Also, docking an older TB1/2 computer here is convenient because the TB display has an 85w Magsafe built in.

Now, as far as going in the "backside" of the TB display-I wouldn't necessarily do it with a TB2 computer, something which I don't currently have. It SHOULD work fine, but the issue is the TB display is a TB1 device, which is about half the speed of TB2. Going directly into the hub from the computer in that case should get higher speeds from the USB-C port on the front and potentially from the USB 3.0 Type A ports.

 

[joevt]

It SHOULD work fine, but the issue is the TB display is a TB1 device, which is about half the speed of TB2

Thunderbolt 1 and Thunderbolt 2 are both 20 Gbps.

The problem with Thunderbolt 1 is that the 20 Gbps is split into two 10 Gbps channels which means anything you connect is limited to 10 Gbps but you can connect multiple things to get 20 Gbps. For example, you can connect two 8 Gbps (1440p60) displays (each Thunderbolt channel has one tunnelled DisplayPort 1.1 signal for a display). I'm not sure if the same applies to tunnelling PCIe data over Thunderbolt. I wonder if you can, in a single Thunderbolt chain, connect two 10 Gbps NVMe drives (two thunderbolt docks each with a connected 10 Gbps USB NVMe drive, or two Thunderbolt devices each with an NVMe) and exceed a total of 10 Gbps? ATTO Disk Benchmark.app can test multiple disks simultaneously without making a RAID 0.

 

[joevt]

Thunderbolt 1 and Thunderbolt 2 are both 20 Gbps.

The problem with Thunderbolt 1 is that the 20 Gbps is split into two 10 Gbps channels which means anything you connect is limited to 10 Gbps but you can connect multiple things to get 20 Gbps. For example, you can connect two 8 Gbps (1440p60) displays (each Thunderbolt channel has one tunnelled DisplayPort 1.1 signal for a display). I'm not sure if the same applies to tunnelling PCIe data over Thunderbolt. I wonder if you can, in a single Thunderbolt chain, connect two 10 Gbps NVMe drives (two thunderbolt docks each with a connected 10 Gbps USB NVMe drive, or two Thunderbolt devices each with an NVMe) and exceed a total of 10 Gbps? ATTO Disk Benchmark.app can test multiple disks simultaneously without making a RAID 0.

I actually have a Thunderbolt 1 Mac now. An iMac14,2.

I connected a couple Thunderbolt 3 NVMe. Each one can do nearly 1000 MB/s.
Both together can do slightly over 1000 MB/s.

Those numbers are all greater than I was expecting (I was mistakenly thinking about the overhead of PCIe 2.5 GT/s x4 or 5 GT/s x2 limit 1000 MB/s which gives ≈750 MB/s) but the Thunderbolt 1 controller is connected via 5 GT/s x4 and 10 Gbps Thunderbolt is actually 1250 MB/s.

USB 10 Gbps is actually 9.7 Gbps = 1212 MB/s but can actually give 1060 MB/s when connected to a Thunderbolt 3 Mac, so you can see that PCIe has more overhead giving lower results in the Thunderbolt 1 case than the USB case even though Thunderbolt 1 is faster than USB 3.1 gen 2 by 0.3 Gbps.

Anyway, it appears I did not get a separate Thunderbolt 1 channel for the second Thunderbolt NVMe device in the chain so no 20 Gbps possibility this way. Maybe Thunderbolt 1 devices could do it. Maybe some software can rearrange the Thunderbolt connections and paths to force a single separate channel for each Thunderbolt 3 device. There's little benefit to the 2 channel connection between the two Thunderbolt 3 devices (unless those devices can communicate with each other without going to the host Thunderbolt controller that is connected upstream with a single channel).

iMac14,2 macOS 12.0.1 Monterey

OWC Thunderbolt 3 Dock
	OWC Mercury Helios 3 (ADATA NVMe)
		Trebleet (Sabrent gen4 NVMe)

#=========================================================================================
┬[0000:00]
├─00:00.0                 #                [8086:0c00] [0600] (rev 06) Host bridge               : Intel Corporation 4th Gen Core Processor DRAM Controller
├┬00:01.0-[01]            # g3x16 > g1x16  [8086:0c01] [0604] (rev 06) PCI bridge                : Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor PCI Express x16 Controller
│├─01:00.0                # g3x16 > g1x16  [10de:119e] [0300] (rev a1) VGA compatible controller : NVIDIA Corporation GK104M [GeForce GTX 780M Mac Edition]
│└─01:00.1                # g3x16 > g1x16  [10de:0e0a] [0403] (rev a1) Audio device              : NVIDIA Corporation GK104 HDMI Audio Controller
├─00:02.0                 #                [8086:0412] [0300] (rev 06) VGA compatible controller : Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller
├─00:14.0                 #                [8086:8c31] [0c03] (rev 05) USB controller            : Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI
├─00:16.0                 #                [8086:8c3a] [0780] (rev 05) Communication controller  : Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1
├─00:1b.0                 # g0x0           [8086:8c20] [0403] (rev 05) Audio device              : Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller
├┬00:1c.0-[02]            # g2x2           [8086:8c10] [0604] (rev d5) PCI bridge                : Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1
│└─02:00.0                # g2x2           [1b4b:9183] [0106] (rev 14) SATA controller           : Marvell Technology Group Ltd. 88SS9183 PCIe SSD Controller
├┬00:1c.2-[ff-fe]         # g2x1 > g1x1    [8086:8c14] [0604] (rev d5) PCI bridge                : Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #3
├┬00:1c.3-[04]            # g2x1 > g1x1    [8086:8c16] [0604] (rev d5) PCI bridge                : Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #4
│├─04:00.0                # g1x1           [14e4:1686] [0200] (rev 01) Ethernet controller       : Broadcom Inc. and subsidiaries NetXtreme BCM57766 Gigabit Ethernet PCIe
│└─04:00.1                # g1x1           [14e4:16bc] [0805] (rev 01) SD Host controller        : Broadcom Inc. and subsidiaries BCM57765/57785 SDXC/MMC Card Reader
├┬00:1c.4-[05-ff]         # g2x4           [8086:8c18] [0604] (rev d5) PCI bridge                : Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #5
│└┬05:00.0-[06-ff]        # g2x4           [8086:1547] [0604] (rev 03) PCI bridge                : Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012]
│ ├┬06:00.0-[07]          # g1x4           [8086:1547] [0604] (rev 03) PCI bridge                : Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012]
│ │└─07:00.0              # g1x4           [8086:1547] [0880] (rev 03) System peripheral         : Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012]
│ ├┬06:03.0-[be-c9]       # g1x4           [8086:1547] [0604] (rev 03) PCI bridge                : Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012]
│ │└┬be:00.0-[bf-c9]      # g1x4           [8086:15d3] [0604] (rev 02) PCI bridge                : Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016]
│ │ ├┬bf:00.0-[c3]        # g3x1 > g2x1    [8086:15d3] [0604] (rev 02) PCI bridge                : Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016]
│ │ │└─c3:00.0            # g2x1           [1b73:1100] [0c03] (rev 10) USB controller            : Fresco Logic FL1100 USB 3.0 Host Controller
│ │ ├┬bf:01.0-[c2]        # g3x1 > g2x1    [8086:15d3] [0604] (rev 02) PCI bridge                : Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016]
│ │ │└─c2:00.0            # g2x1           [1b73:1100] [0c03] (rev 10) USB controller            : Fresco Logic FL1100 USB 3.0 Host Controller
│ │ ├┬bf:02.0-[c1]        # g3x1 > g1x1    [8086:15d3] [0604] (rev 02) PCI bridge                : Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016]
│ │ │└─c1:00.0            # g1x1           [11c1:5901] [0c00] (rev 08) FireWire (IEEE 1394)      : LSI Corporation FW643 [TrueFire] PCIe 1394b Controller
│ │ ├┬bf:03.0-[c0]        # g3x1 > g1x1    [8086:15d3] [0604] (rev 02) PCI bridge                : Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016]
│ │ │└─c0:00.0            # g1x1           [8086:1533] [0200] (rev 03) Ethernet controller       : Intel Corporation I210 Gigabit Network Connection
│ │ └┬bf:04.0-[c4-c9]     # g1x4           [8086:15d3] [0604] (rev 02) PCI bridge                : Intel Corporation JHL6540 Thunderbolt 3 Bridge (C step) [Alpine Ridge 4C 2016]
│ │  └┬c4:00.0-[c5-c9]    # g1x4           [8086:1578] [0604]          PCI bridge                : Intel Corporation DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
│ │   ├┬c5:01.0-[c6]      # g3x4           [8086:1578] [0604]          PCI bridge                : Intel Corporation DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
│ │   │└─c6:00.0          # g3x4           [1cc1:8201] [0108] (rev 03) Non-Volatile memory controller : ADATA Technology Co., Ltd. XPG SX8200 Pro PCIe Gen3x4 M.2 2280 Solid State Drive
│ │   └┬c5:04.0-[c7-c9]   # g1x4           [8086:1578] [0604]          PCI bridge                : Intel Corporation DSL6540 Thunderbolt 3 Bridge [Alpine Ridge 4C 2015]
│ │    └┬c7:00.0-[c8-c9]  # g1x4           [8086:15da] [0604] (rev 02) PCI bridge                : Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step) [Alpine Ridge 2C 2016]
│ │     ├┬c8:01.0-[c9]    # g3x4           [8086:15da] [0604] (rev 02) PCI bridge                : Intel Corporation JHL6340 Thunderbolt 3 Bridge (C step) [Alpine Ridge 2C 2016]
│ │     │└─c9:00.0        # g4x4 > g3x4    [1987:5016] [0108] (rev 01) Non-Volatile memory controller : Phison Electronics Corporation E16 PCIe4 NVMe Controller
│ │     └┬c8:04.0-[XX]    # g1x4           [ffff:ffff] [0604] (rev 02) PCI bridge                : Illegal Vendor ID Device
│ ├┬06:04.0-[83]          # g1x4           [8086:1547] [0604] (rev 03) PCI bridge                : Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012]
│ ├┬06:05.0-[48]          # g1x4           [8086:1547] [0604] (rev 03) PCI bridge                : Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012]
│ └┬06:06.0-[0d]          # g1x4           [8086:1547] [0604] (rev 03) PCI bridge                : Intel Corporation DSL3510 Thunderbolt Controller [Cactus Ridge 4C 2012]
├─00:1f.0                 #                [8086:8c44] [0601] (rev 05) ISA bridge                : Intel Corporation Z87 Express LPC Controller
├─00:1f.2                 #                [8086:8c02] [0106] (rev 05) SATA controller           : Intel Corporation 8 Series/C220 Series Chipset Family 6-port SATA Controller 1 [AHCI mode]
└─00:1f.3                 #                [8086:8c22] [0c05] (rev 05) SMBus                     : Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller

 

[Amethyst1]

Those numbers are all greater than I was expecting

AnandTech’s review of the Promise Pegasus R6 (Thunderbolt 1) also shows it peaking at 1000 MB/s.

 

[Amethyst1]

I actually have a Thunderbolt 1 Mac now.

Can you test if dual monitors work from a single Thunderbolt 3 dock (like they do on Thunderbolt 3 Macs)?

 

[joevt]

Can you test if dual monitors work from a single Thunderbolt 3 dock (like they do on Thunderbolt 3 Macs)?

It works. I connected two 4K60 displays to a OWC Thunderbolt 3 Dock (connected to the iMac14,2 running macOS Monterey). The displays are using the Mini DisplayPort connector and the downstream Thunderbolt 3 port with Mini DisplayPort to DisplayPort adapter and USB-C to DisplayPort adapter.

It's actually much easier to connect two 4K displays to a Thunderbolt 1 Mac (like this iMac14,2) compared to a Thunderbolt 2 Mac, since the displays will only connect at HBR link rate (Thunderbolt 1 can do two of those, each down a separate 10 Gbps channel). In a Thunderbolt 2 Mac, a 4K60 display connects as HBR2 leaving no bandwidth for another display (so you need to connect a HBR display first, then a 4K60 display to the other port of the dock, then replace the HBR display with the second 4K60 display).

The Thunderbolt 1 controller modifies the DPCD of the displays so that they report a max link rate of HBR (DPCD can be seen in the output of the AGDCDiagnose command). Thunderbolt 3 Alpine Ridge does the same (except the max is HBR2).

HBR allows 8bpc up to 360 MHz and 10bpc up to 288 MHz. macOS accepts timings up to 360 MHz however, only the timings that are under 288 MHz will work. It's as if macOS is not reducing the bit depth to 8 bpc (Nvidia GTX 780M) for the modes that are greater than 288 MHz. The frame buffers are reported to be 8bpc. The AGDCDiagnose output does not show pixel depth info for Nvidia or Intel GPUs so I don't know for sure if it's trying to output 10bpc.

Back to my idea of getting two separate 10 Gbps PCIe links from one Thunderbolt 1 port: the Thunderbolt 1 controller does have 4 PCI down adapters according to IORegistryExplorer.app. This seems reasonable since there are 2 ports with 2 channels each. I guess we have to learn about how the adapters and channels/links and paths can be setup to know for sure. It seems to me that if a separate channel could be assigned to the second Thunderbolt device, then the second Thunderbolt device would not appear as being connected to the first - at least in the PCIe tree.

 

[Amethyst1]

It works. I connected two 4K60 displays to a OWC Thunderbolt 3 Dock (connected to the iMac14,2 running macOS Monterey). The displays are using the Mini DisplayPort connector and the downstream Thunderbolt 3 port with Mini DisplayPort to DisplayPort adapter and USB-C to DisplayPort adapter.

Great, thanks for testing that. I wonder if it also works on macOS versions older than Sierra (i.e. those that predate Thunderbolt 3).

It's actually much easier to connect two 4K displays to a Thunderbolt 1 Mac (like this iMac14,2) compared to a Thunderbolt 2 Mac, since the displays will only connect at HBR link rate (Thunderbolt 1 can do two of those, each down a separate 10 Gbps channel).

Yep, that's the setup I tested: two 4K60 displays, each limited to 1440p60 or 4K30.

 

[joevt]

I connected two 4K60 displays to a OWC Thunderbolt 3 Dock (connected to the iMac14,2 running macOS Monterey).

HBR allows 8bpc up to 360 MHz and 10bpc up to 288 MHz. macOS accepts timings up to 360 MHz however, only the timings that are under 288 MHz will work. It's as if macOS is not reducing the bit depth to 8 bpc (Nvidia GTX 780M) for the modes that are greater than 288 MHz. The frame buffers are reported to be 8bpc. The AGDCDiagnose output does not show pixel depth info for Nvidia or Intel GPUs so I don't know for sure if it's trying to output 10bpc.

SwitchResX in High Sierra shows default max pixel clock for each display as 358.20 MHz but modes greater than 288 MHz still don't work - same as Monterey.

I also retested the Thunderbolt NVMe #44 with the two displays running.

Read speed is only slightly reduced from the near 1000 MB/s value since DisplayPort bandwidth is mostly one direction.
Write speed is greatly reduced down to 352.87 MB/s = 2.82296 Gbps.

Both displays are running at 262.75 MHz. This is 6.306 Gbps for 8bpc and 7.8825 Gbps for 10bpc. I think from previous tests we can assume the displays are getting 10bpc even though the macOS framebuffer is 8bpc because nothing is displayed when trying to go more than 288 MHz.

7.8825 Gbps + 2.82296 Gbps = 10.70546 Gbps. That can't be right. So maybe the displays are getting 8bpc or my DisplayPort bandwidth calculation is adding too much bandwidth overhead (since I am giving blanking pixels the same bits as active pixels).

6.306 Gbps + 2.82296 = 9.12896 Gbps. This makes more sense. There's no change if I set all the framebuffers to 10bpc (using SwitchResX Billions of Colors mode). There's no HDR option for my XV273K from the iMac which would force 10bpc.

There's no indication of which display is connected to the same channel as the PCIe. If I disconnect one of them, then PCIe write might still be limited to 352.87 MB/s. In that case, I can reconnect that display, and disconnect the other, then get the near 1000 MB/s write speed.