MP 7,1 Meaning of the dots on the Mac Pro 2019 PCIe slot covers [and PCIe brackets]?

[thomast0001]

Here's something I haven't seen mentioned before. If you look carefully at the PCIe slot covers of the Mac Pro 2019, you'll notice that on the tongue of the slot cover there are little dots debossed into them. The pattern of dots varies from slot cover to slot cover. Furthermore, the dots are on both sides of the tongue, with different patterns on each side!

I've tried to figure out what the dot patterns mean to no avail. I thought perhaps they were braille, but I haven't made sense of the patterns. The three I've removed from the machine are for slots 5, 6, and 7. The dots don't seem to correspond numerically to the braille equivalent of those numbers. Also, there are too many dots to represent binary (101, 110, and 111 for example).

Obviously which slot a cover is put in doesn't matter, but I can imagine the obsessive-compulsive sorts are going to go bonkers trying to figure out which one goes where after they've been taken out.

Note that the debossed dots don't appear to be punched. They look like they were machined! Someone went to a lot of trouble to add those dots!

At the moment this almost feels like a little easter egg. So what do you all think?

[edit] As mentioned further down in the comments, we've discovered the dot patterns are also on the I/O card and graphics card PCIe brackets. So it's not limited to the slot covers.

 

[Snow Tiger]

Here's something I haven't seen mentioned before. If you look carefully at the PCIe slot covers of the Mac Pro 2019, you'll notice that on the tongue of the slot cover there are little dots debossed into them. The pattern of dots varies from slot cover to slot cover. Furthermore, the dots are on both sides of the tongue, with different patterns on each side!

I've tried to figure out what the dot patterns mean to no avail. I thought perhaps they were braille, but I haven't made sense of the patterns. The three I've removed from the machine are for slots 5, 6, and 7. The dots don't seem to correspond numerically to the braille equivalent of those numbers. Also, there are too many dots to represent binary (101, 110, and 111 for example).

Obviously which slot a cover is put in doesn't matter, but I can imagine the obsessive-compulsive sorts are going to go bonkers trying to figure out which one goes where after they've been taken out.

Note that the debossed dots don't appear to be punched. They look like they were machined! Someone went to a lot of trouble to add those dots!

At the moment this almost feels like a little easter egg. So what do you all think?

I hate you . I won't be able to sleep tonight until the mystery is solved and my MP7,1 is currently undergoing stress tests , so I can't remove her housing yet . It really shouldn't matter what slot any particular PCIe bracket fits into as they should be interchangeable ! Maybe its in morse code or something . And it's probably an in house joke . Do you have pictures ?
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I happened to think , maybe they are quality control markings to differentiate between stamping machines at the industrial conversion facility where the brackets were made .

 

[thomast0001]

I hate you . I won't be able to sleep tonight until the mystery is solved and my MP7,1 is currently undergoing stress tests , so I can't remove her housing yet . It really shouldn't matter what slot any particular PCIe bracket fits into as they should be interchangeable ! Maybe its in morse code or something . And it's probably an in house joke . Do you have pictures ?

Here are pictures of the front and back. You’ll need to look carefully to see the dots.

 

[Snow Tiger]

Are the brackets made of solid plastic ? If so , maybe they are atypical plastic injection mold position markings for quality control . I'm an ex-manufacturer here ... Seems elaborate . Maybe if you line up all the brackets in sequence as installed at the factory they form a coded message ?

 

[DeltaMac]

As you can see, they are not identical.
Be careful how you insert them -- There's only one combination that will begin the sequence that opens the portal.
I hope you don't figure it out...

 

[thomast0001]

Are the brackets made of solid plastic ? If so , maybe they are atypical plastic injection mold position markings for quality control . I'm an ex-manufacturer here ... Seems elaborate . Maybe if you line up all the brackets in sequence as installed at the factory they form a coded message ?

Nope, the brackets are a complex shape milled from a solid piece of aluminum stock. Looking at the dots, it looks like they milled them using the same end mill used to mill the surrounding border. The dots look like a shallow plunge cut. Sooooo, elaborate indeed!
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As you can see, they are not identical.
Be careful how you insert them -- There's only one combination that will begin the sequence that opens the portal.
I hope you don't figure it out...

I wouldn’t be surprised if one or more people have been waiting for someone to notice the dots. So...... First! (Or at least first to report it as far as I can tell.)

So....... do I now get a visit from Stargate Command? It’s O’Neill. With two l’s! 😋

 

[Snow Tiger]

Well , its definitely not Braille . It's in the wrong format for that . Braille cells are three dots high and the bracket markings are only two dots high .

 

[thomast0001]

Well , its definitely not Braille . It's in the wrong format for that . Braille cells are three dots high and the bracket markings are only two dots high .

Actually no. If you look carefully, you’ll see the dots are arranged in two rows of six. Think of two Braille characters, one above the other. But like I said, they don’t seem to spell anything, at least with the ones I have here. You’ll notice various Braille punctuation chars for example. We need more examples and complete sets from peoples’ machines.

 

[Snow Tiger]

So....... do I now get a visit from Stargate Command? It’s O’Neill. With two l’s! 😋

Now , this is making some sense ...

The brackets are stargate address numbers that you have to place in the proper sequence in order to activate the portal built into the chassis of every Mac Pro 7,1 . What portal ? How about this one :

The portal is only activated with the housing removed , otherwise its completely safe .

And , the portals only are big enough for rodents - like the chipmunk that lives under my house .

I knew there was a reason why my rent was so cheap - they're subsidizing me ! Interstellar rodents are using my Mac as a transportation hub . And they all look alike to me , too ! Sneaky bastards .

 

[Nermal]

We need someone with a different MP to see whether they have the same or different dots.

 

[Snow Tiger]

We need someone with a different MP to see whether they have the same or different dots.

Well , as soon as my stress test is over I'm going to open her up and take a look see . My brackets are still in factory configuration , I think .
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Actually no. If you look carefully, you’ll see the dots are arranged in two rows of six. Think of two Braille characters, one above the other. But like I said, they don’t seem to spell anything, at least with the ones I have here. You’ll notice various Braille punctuation chars for example. We need more examples and complete sets from peoples’ machines.

Au contraire ! The official reading direction of Braille is left to right , not top to down . There's probably a reason for that - maybe to avoid confusion .

Also , isn't Braille supposed to use raised dots and not indentations ? Brush your fingers over those inscriptions to see if you can feel them .

 

[thomast0001]

Well , as soon as my stress test is over I'm going to open her up and take a look see . My brackets are still in factory configuration , I think .
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Au contraire ! The official reading direction of Braille is left to right , not top to down . There's probably a reason for that - maybe to avoid confusion .

Also , isn't Braille supposed to use raised dots and not indentations ? Brush your fingers over those inscriptions to see if you can feel them .

Heh, this has little to do with official reading direction and whether the dots can be felt. ? If the dots represent Braille (and that’s a big IF), it’d be an easter egg rather than some official Braille usage.

At this point I see the dots as a puzzle. The encoding can be whatever the perpetrator desires. Braille is one possibility. Soon I’ll have a chance to get a look at all the slot covers so we’ll have a complete set of values we can compare with other machines. We can try different ideas as to how to interpret the values. The most important data we can gather is to see if the same values exist between machines, or are repeated within a machine, and also whether this is US specific or also in machines elsewhere. (I’m in the US. So are those slot covers manufactured here or in China for example?)

 

[DeltaMac]

hmm.... You might "show" those covers to a blind guy. Maybe he will "feel" the answer to your quest.
(Or, you will get your answer - not braille-connected in any way)

 

[arock]

I have removed 5 of my slot covers. All of them have the dots on both sides, and all of them are different dot patterns than the ones pictured above. So it's not simply that the dots identify which slot they are from. Is it possible that they can be used as an alternate serial number verification to help identify fakes? There are not enough unique patterns for each slot cover to have a globally unique pattern - see below for analysis. But together they many be meaningful.

Given 2 rows of 6 dots, we have 2^12=4096 possible dot patterns. If you buy the 580X and no other add-in cards, your Mac Pro comes with 9 of these slot covers. Even if they are only unique on the front or back (but a front could match a back pattern), they could only sell 455 Mac Pros before someone got a duplicate. Of course people are buying with the Vega II/Duo card(s) and Afterburner, so some Macs will have less slot covers. A fully maxed out config would only have 3 slot covers included. Therefore the maximum Mac Pros sold before repetition would be 1365. The truth is between those two numbers.

 

[Snow Tiger]

I have removed 5 of my slot covers. All of them have the dots on both sides, and all of them are different dot patterns than the ones pictured above. So it's not simply that the dots identify which slot they are from. Is it possible that they can be used as an alternate serial number verification to help identify fakes? There are not enough unique patterns for each slot cover to have a globally unique pattern - see below for analysis. But together they many be meaningful.

Given 2 rows of 6 dots, we have 2^12=4096 possible dot patterns. If you buy the 580X and no other add-in cards, your Mac Pro comes with 9 of these slot covers. Even if they are only unique on the front or back (but a front could match a back pattern), they could only sell 455 Mac Pros before someone got a duplicate. Of course people are buying with the Vega II/Duo card(s) and Afterburner, so some Macs will have less slot covers. A fully maxed out config would only have 3 slot covers included. Therefore the maximum Mac Pros sold before repetition would be 1365. The truth is between those two numbers.

Maybe someone should call Apple ?

I have AppleCare on my Mac so I can always call them for customer support .

I can just see the conversation now ...

Apple : "Thank you for calling Apple Care . Please state the nature of your Apple Emergency ."

Me : "Ummm ... there are dots on my Mac's PCIe brackets ..."

Apple : "Don't worry , Sir ! And Don't move . Help is on the way !"

 

[thomast0001]

I have removed 5 of my slot covers. All of them have the dots on both sides, and all of them are different dot patterns than the ones pictured above. So it's not simply that the dots identify which slot they are from. Is it possible that they can be used as an alternate serial number verification to help identify fakes? There are not enough unique patterns for each slot cover to have a globally unique pattern - see below for analysis. But together they many be meaningful.

Given 2 rows of 6 dots, we have 2^12=4096 possible dot patterns. If you buy the 580X and no other add-in cards, your Mac Pro comes with 9 of these slot covers. Even if they are only unique on the front or back (but a front could match a back pattern), they could only sell 455 Mac Pros before someone got a duplicate. Of course people are buying with the Vega II/Duo card(s) and Afterburner, so some Macs will have less slot covers. A fully maxed out config would only have 3 slot covers included. Therefore the maximum Mac Pros sold before repetition would be 1365. The truth is between those two numbers.

Thanks for checking it out! I’ve got more news to share now that I have my machine open. On a hunch, I yanked the I/O card to look at its slot cover PCIe bracket. Low and behold... it has dot patterns as well!

This possibly demonstrates I think that the dots are formed into two 6 dot fields on each side, one field stacked above the other, because in this case there are no dots on both sides in one field. That doesn’t mean it’s Braille, but if it is I can’t make sense of it. In Braille the two patterns I think represent slash (/) on one side and either colon : ) or less than (<) on the other, depending on orientation.

If you don’t mind, could you please open your machine and take a look at your I/O card?

 

[ZombiePhysicist]

You would think they somehow represent the slot number they cover and perhaps the number of lanes for that slot, no?

 

[thomast0001]

And now, the graphics card. This is a 580x (dreaming of being a W5700X...)

Dots are only on the grilled slot cover PCIe bracket.

So we need more samples...
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You would think they somehow represent the slot number they cover, no?

We need some comparisons, especially now that we see the dot patterns on the graphics card! Considering people could put such a card in more than one location, I suspect the pattern does not represent a location.

My guess is that it’s a factory machining “cell” identifier, for those familiar with cell-based manufacturing processes. There are too few values to represent a lot number I think. However, with more examples we may discern a pattern.

 

[thomast0001]

Here are the remaining slot covers, top to bottom.

 

[bxs]

One of my guesses for the meaning/significance of the dots is that quite likely all of these slot covers are milled from a single piece of material and the dots are meaningful to the numerically driven milling machine.

From your photos it appears the dot matrix is identical on both sides of each slot cover.

 

[thomast0001]

One of my guesses for the meaning/significance of the dots is that quite likely all of these slot covers are milled from a single piece of material and the dots are meaningful to the numerically driven milling machine.

From your photos it appears the dot matrix is identical on both sides of each slot cover.

As for having meaning to the machine, I doubt it. CNC doesn’t need that kind of feedback. Also, imagine the sensor required to read it. It just seems overly complicated and unnecessary. Generally at most you just need some kind of corner indexing, and that typically exists outside of the final milled parts.

However, it means something. Another guess is that whomever wrote the milling instructions decided to have a bit of fun. “Hey look! These CNC machines have a built-in RAND function! Watch this! (I wonder if anyone will notice...?)” ?

 

[Snow Tiger]

If those dots were only on Apple sold PCIe Cards and not on the brackets as well , I would venture a guess it was a bandwidth indicator involving the two PCIe Pools ( A + B ) in this Mac . But the dots are on brackets that don't consume bandwidth , of course ...

 

[konqerror]

As for having meaning to the machine, I doubt it. CNC doesn’t need that kind of feedback. Also, imagine the sensor required to read it.

It wouldn't be for the machine to read, it would be for QA to trace defects and determine if its a one-off material problem or if the tooling is wearing out. Similar marks are the printing plate position marks or numbers on stamps and currency.

As you noted it's apparently done in the same end mill they used in the final pass. Using a code instead of text saves them a tool change or separate operation through say a laser engraver.

 

[jasoncarle]

This is my favorite thread here!

 

[Snow Tiger]

Maybe the dots are for machine vision automated inspections ?

Those dots would be a unique type of data matrix for this application , though .

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Let's have several people here take pictures of the same type of card ( I/O card , 580X Card , etc . ) and see if those dot patterns are the same for each type of product . If they are , maybe machines are used for picking or assembly in some fashion . Maybe Apple's factory is more sophisticated than those official videos indicate .