Apple's "Digit-Comma-Digit" model numbering system - what's the rationale?

[Diamond Dave]

I was wondering if anyone definitively knew the rules/logic/rationale behind Apple's "Digit-Comma-Digit" model numbering system?

For example, System Profiler lists my own Mac as

Machine Model: PowerMac3,6

and (according to Wikipedia) all the Mac Pros released so far seem to use the numbers 1,1 through 5,1.

I can understand the digits before the comma - they obviously signify a major release (or possibly a new/different processor from the predecessor's one?), but what of the digit after? If every Mac Pro is a "X,1", why bother with the ",1" at all?

Also, why the comma rather than a full stop/period? I've only ever seen a comma used in place of a decimal point before in continental Europe for pricing things. For example, something might be marked "39,95" to indicate that it costs 39 Euros & 95 Cents. Why would Apple use the comma?

 

[CaptainChunk]

I have never understood the comma versus decimal thing. But from what I understand, the number after the comma denotes the revision number in that model generation. Mac Pros don't go past revision 1 because they generally receive major redesigns internally (different CPU architecture, etc.). However, I do think the 2,1 MP (8-core version of the 2006 released early the next year) should have been 1,2 instead.

 

[nanofrog]

ISO decimal mark system (period to denote number groupings, such as a thousand = 1.000, and a comma for fractions; 1/100 = 0,01). This is usually used by non-English speaking nations.

I suspect, as it's an International specification, Apple decided to use it due to the fact it's recognizable in 162 countries.

 

[ScottishCaptain]

However, I do think the 2,1 MP (8-core version of the 2006 released early the next year) should have been 1,2 instead.

The 8-core version had hardware changes internally. It dropped support for dynamic PCI-Express lane reconfiguration, and gained EFI 64-bit support.

I can understand the digits before the comma - they obviously signify a major release (or possibly a new/different processor from the predecessor's one?), but what of the digit after? If every Mac Pro is a "X,1", why bother with the ",1" at all?

Uh, because that maintains uniformity with the platform string Apple has always used. "MacPro5" is not specific enough. In such a scenario, it would be up to the software to assume that you really mean "MacPro5,1" in that case. If the software's assumption ever changed so that "MacPro5" became "MacPro5,0" instead, then that could potentially break a piece of code that never expected the minor revision to return ,0 instead of ,1.

We're talking about two bytes of characters here. I'm surprised that even warranted a thread.

-SC

 

[goMac]

If every Mac Pro is a "X,1", why bother with the ",1" at all?

Because this hasn't been true for the other models, and may not hold true for the Mac Pro in the future.

It's harder to change the format of the number after the fact, then it is to prepare for that sort of situation.

 

[G-Force]

The 8-core version had hardware changes internally. It dropped support for dynamic PCI-Express lane reconfiguration, and gained EFI 64-bit support.

I believe your are talking about the Mac Pro3,1, which is the 2008 8-core. However, there was an 8-core Mac Pro2,1 which is essentially the same as the 2006 Mac Pro1,1 (though it had newer firmware with updated cpu codes I believe). It did not have EFI64 for sure, the 2008 does.

 

[nanofrog]

The 8-core version had hardware changes internally. It dropped support for dynamic PCI-Express lane reconfiguration, and gained EFI 64-bit support.

G-Force is correct.

The 2006/7 models didn't change, except that Intel introduced Quad core variants, and Apple made them available for MP customers. The board and firmware are the same (MP Identifier is all they changed, which isn't part of the functional code; as a result, 2006 owners can drop a pair of 5365's in for example, and it works without a firmware flash).

But the hardware was changed in the 2008 models to accommodate the newer 54xx CPU's, which required different chipsets (faster FSB). And it's when Apple first released EFI64 firmware in a Mac Pro.