MacBook Pro retina display does not run 3 Thunderbolt displays

[qubit]

just for the record, A MacBook Pro at this time, does not run three 27
inch Thunderbolt displays concurrently.

Had the MBP delivered 2 days ago, and connected 2 TB displays ( one DOA;
it happens, no biggie). Took the opportunity on phone to Apple to ask if
it would run a third TB display via HDMI, so I could have an extended
desktop; after some referral, answer is yes, so I ordered a third, A
replacement for the DOA arrived today, and the new third display.

2 connected via TB, the third via HDMI m-m cable ( techlynx) to a TB
(f-m) adaptor; bought form the local Apple independent who confirmed it
would work ( note that is not 'should' work) You don't know until you
try, and they obviously have not yet tried. I raised my preference for
Apple brand cables, don't have them theses will be ok. Having captured a
lot of data form live systems over the years, I know a little about
cable quality ramifications, but when in Rome, without an option...

Connect the third display via HDMI, nada.
Tried the combinations, 1-2 daisy chain, 3rd to the second TB port on
the MBP, nada. etc.

TB-daisy-TB MBP runs the 2 TB, but same plus 3rd into the second MBP TB
port nada


Phone to Apple again.

Conclusion, the web info indicates 2 TB plus HDMI. That means a HDMI
dive, but not a TB device connected via a HDMI to TB cable/adapter.

At least at the moment. That may or may not change when/if Apple have a
cable.

It is curious though, the the GPU supposedly has the grunt to run 2xTB
display and a HDMI, but not similar pixel push over a TB combo ( daisy
chained...) So it is presumptively a cable/adapter issue.

Apple as ever ( 25 years of ever), on the phone are as good as one might
reasonably expect. Your mileage may vary, mine has always been good. No.
3 goes back Friday.

[dorayme]

In article <jtjib9$e84$1...@speranza.aioe.org>,

qubit <qu...@quandoveloce.com> wrote:

> just for the record, A MacBook Pro at this time, does not run three 27
> inch Thunderbolt displays concurrently.

I was hoping for but knew I could not have even *two* good big
displays with my 2010 Macbook. Settled for an excellent 26" main and
use the MB's tiny 13" screen as the second. All one big desktop. But
the MB's is too small to be always useful because text is too tiny for
general comfort.

Once did have three screens on an old Powermac but the distraction and
mouse travel made it less practical than it was spectacular.

--
dorayme

[David Empson]

qubit <qu...@quandoveloce.com> wrote:

> just for the record, A MacBook Pro at this time, does not run three 27
> inch Thunderbolt displays concurrently.

That's not surprising. The graphics controller only supports two
external displays using Mini DisplayPort or Thunderbolt. You have to use
the HDMI connector for a third display.

> Had the MBP delivered 2 days ago, and connected 2 TB displays ( one DOA;
> it happens, no biggie). Took the opportunity on phone to Apple to ask if
> it would run a third TB display via HDMI, so I could have an extended
> desktop; after some referral, answer is yes, so I ordered a third, A
> replacement for the DOA arrived today, and the new third display.

I don't understand how someone at Apple could have answered yes to that
question as it is clearly impossible with currently available products.
An Apple Thunderbolt display can only accept a display signal from
Thunderbolt, not from HDMI.

As far as I know, there are no adapters which convert an HDMI output to
Thunderbolt.

There are adapters which convert from HDMI to DisplayPort (or Mini
DisplayPort), e.g. this one from Belfan:

http://www.belfan.com/products_detail_D.asp?id=1790

Note that it is a box with a separate power supply - converting from
HDMI to DisplayPort is relatively complex and I expect there is a fair
amount of circuitry inside.

This adapter won't work with an Apple Thunderbolt display, as that
display requires a Thunderbolt connection to a computer, and won't work
with a DisplayPort (or Mini DisplayPort) video source.

> 2 connected via TB, the third via HDMI m-m cable ( techlynx) to a TB
> (f-m) adaptor;

An adapter with Mini DisplayPort and HDMI connectors is probably
receiving video via DisplayPort and outputting it via HDMI. This sort
don't work the other way around.

> bought form the local Apple independent who confirmed it would work ( note
> that is not 'should' work)

Which adapter, exactly?

> You don't know until you try, and they obviously have not yet tried. I
> raised my preference for Apple brand cables, don't have them theses will
> be ok. Having captured a lot of data form live systems over the years, I
> know a little about cable quality ramifications, but when in Rome, without
> an option...
>
> Connect the third display via HDMI, nada.

The Thunderbolt display doesn't accept HDMI input so that won't work.

You need a third display which accepts HDMI input. That means a
third-party display, not an Apple one.

> Tried the combinations, 1-2 daisy chain, 3rd to the second TB port on
> the MBP, nada. etc.
>
> TB-daisy-TB MBP runs the 2 TB, but same plus 3rd into the second MBP TB
> port nada
>
>
> Phone to Apple again.
>
> Conclusion, the web info indicates 2 TB plus HDMI. That means a HDMI
> dive, but not a TB device connected via a HDMI to TB cable/adapter.
>
> At least at the moment. That may or may not change when/if Apple have a
> cable.
>
> It is curious though, the the GPU supposedly has the grunt to run 2xTB
> display and a HDMI, but not similar pixel push over a TB combo ( daisy
> chained...) So it is presumptively a cable/adapter issue.

The graphics controllers have dedicated outputs which generate certain
types of video signals. There are enough DisplayPort outputs to drive
two displays, plus there is a dedicated HDMI output which goes to the
external HDMI connector, and whatever is needed to drive the internal
display (probably another DisplayPort signal).

There aren't enough DisplayPort outputs available from the graphics
controllers to drive three displays via Thunderbolt.

Even if there were, you can't daisy-chain three displays through a
single Thunderbolt port as each DisplayPort signal ties up half of the
available bandwidth of Thunderbolt.

With two Thunderbolt ports, the only reason you can't drive three
displays via Thunderbolt is that there are only two compatible signals
available.

> Apple as ever ( 25 years of ever), on the phone are as good as one might
> reasonably expect. Your mileage may vary, mine has always been good. No.
> 3 goes back Friday.

--
David Empson
dem...@actrix.gen.nz

[qubit]

On 11/07/12 11:51 PM, Lewis wrote:
> In message <jtjib9$e84$1...@speranza.aioe.org>

> qubit <qu...@quandoveloce.com> wrote:
>
>> just for the record, A MacBook Pro at this time, does not run three 27
>> inch Thunderbolt displays concurrently.
>

> It runs 2 Thunderbolt and 1 HDMI.
>
> <http://blog.macsales.com/14241-macbook-pro-15-with-retina-display-can-run-3-external-displays2>
>
>

that's the idea I know. But I was trying to connect A TB display via
HDMI. ALso tried direct HDMI to a plasma TV only, recognised the device
but no signal.

[qubit]

On 11/07/12 11:10 PM, David Empson wrote:
> qubit <qu...@quandoveloce.com> wrote:
>
>> just for the record, A MacBook Pro at this time, does not run three 27
>> inch Thunderbolt displays concurrently.
>
> That's not surprising. The graphics controller only supports two
> external displays using Mini DisplayPort or Thunderbolt. You have to use
> the HDMI connector for a third display.

That's the idea I know now, but couldn't get HDMI to work either.

>
>> Had the MBP delivered 2 days ago, and connected 2 TB displays ( one DOA;
>> it happens, no biggie). Took the opportunity on phone to Apple to ask if
>> it would run a third TB display via HDMI, so I could have an extended
>> desktop; after some referral, answer is yes, so I ordered a third, A
>> replacement for the DOA arrived today, and the new third display.
>
> I don't understand how someone at Apple could have answered yes to that
> question as it is clearly impossible with currently available products.
> An Apple Thunderbolt display can only accept a display signal from
> Thunderbolt, not from HDMI.

They went away and looked for info, which sounded like the same page I
had found, and gave the advise it would work ( which is why I bought teh
3rd display).

>
> As far as I know, there are no adapters which convert an HDMI output to
> Thunderbolt.

Well the local Apple independent sold me a HDMI cable and HDMI to TB
adapter (techlynx), after I stated what hardware I had and that I wanted
3 concurrent displays.

>
> There are adapters which convert from HDMI to DisplayPort (or Mini
> DisplayPort), e.g. this one from Belfan:
>
> http://www.belfan.com/products_detail_D.asp?id=1790
>
> Note that it is a box with a separate power supply - converting from
> HDMI to DisplayPort is relatively complex and I expect there is a fair
> amount of circuitry inside.
>
> This adapter won't work with an Apple Thunderbolt display, as that
> display requires a Thunderbolt connection to a computer, and won't work
> with a DisplayPort (or Mini DisplayPort) video source.
>
>> 2 connected via TB, the third via HDMI m-m cable ( techlynx) to a TB
>> (f-m) adaptor;
>
> An adapter with Mini DisplayPort and HDMI connectors is probably
> receiving video via DisplayPort and outputting it via HDMI. This sort
> don't work the other way around.
>
>> bought form the local Apple independent who confirmed it would work ( note
>> that is not 'should' work)
>
> Which adapter, exactly?

Techlynx female HDMI to male TB, don't have the number as took the back
yesterday. But looking at the techlynx website, I suspect it was the
MINIDP-HDMI-2, which is obvious now that it is a mini display port. So
they didn't give me what I asked for ( I had called to ask if they had
cable to go HDMI to TB, and was specific again when I went to the store
a half an hour later). And I didn't recognise the coding either.

>>
>> It is curious though, the the GPU supposedly has the grunt to run 2xTB
>> display and a HDMI, but not similar pixel push over a TB combo ( daisy
>> chained...) So it is presumptively a cable/adapter issue.
>
> The graphics controllers have dedicated outputs which generate certain
> types of video signals. There are enough DisplayPort outputs to drive
> two displays, plus there is a dedicated HDMI output which goes to the
> external HDMI connector, and whatever is needed to drive the internal
> display (probably another DisplayPort signal).
>
> There aren't enough DisplayPort outputs available from the graphics
> controllers to drive three displays via Thunderbolt.
>
> Even if there were, you can't daisy-chain three displays through a
> single Thunderbolt port as each DisplayPort signal ties up half of the
> available bandwidth of Thunderbolt.
>
> With two Thunderbolt ports, the only reason you can't drive three
> displays via Thunderbolt is that there are only two compatible signals
> available.
>

Ok, get it.


Hopefully next year, when the MacPro update/revision supports TB, 3 TB
display desktop will be possible.

Thanks

[David Empson]

qubit <qu...@quandoveloce.com> wrote:

> On 11/07/12 11:10 PM, David Empson wrote:
> > qubit <qu...@quandoveloce.com> wrote:
> >
> >> just for the record, A MacBook Pro at this time, does not run three 27
> >> inch Thunderbolt displays concurrently.

[...]

> > As far as I know, there are no adapters which convert an HDMI output to
> > Thunderbolt.
>
> Well the local Apple independent sold me a HDMI cable and HDMI to TB
> adapter (techlynx), after I stated what hardware I had and that I wanted
> 3 concurrent displays.

Techlynx (in Australia) sells a Mini Displayport to HDMI adapter
(MINIDP-HDMI-2). This takes video (and audio, if available) from a Mini
DisplayPort output on a computer, and converts it to HDMI, which can
then be connected to an HDMI input on the display.

It doesn't work the other way around.

(They have a variant which gets audio from USB, which would be useful
with older Mac models that have Mini DisplayPort but don't supply audio
via Mini-DP.)

Techlynx don't sell any products which convert an HDMI signal into
DisplayPort, Mini DisplayPort, or Thunderbolt.

> > An adapter with Mini DisplayPort and HDMI connectors is probably
> > receiving video via DisplayPort and outputting it via HDMI. This sort
> > don't work the other way around.
> >
> >> bought form the local Apple independent who confirmed it would work ( note
> >> that is not 'should' work)
> >
> > Which adapter, exactly?
>
> Techlynx female HDMI to male TB, don't have the number as took the back
> yesterday. But looking at the techlynx website, I suspect it was the
> MINIDP-HDMI-2, which is obvious now that it is a mini display port.

That's the one I found on their web site.

> So they didn't give me what I asked for ( I had called to ask if they had
> cable to go HDMI to TB, and was specific again when I went to the store a
> half an hour later). And I didn't recognise the coding either.

Looks like it. Whoever you were talking to at Apple didn't understand
your requirements, or they were confused about what the adapter actually
did.

> Hopefully next year, when the MacPro update/revision supports TB, 3 TB
> display desktop will be possible.

We will have to wait and see what next year's GPUs allow.

> Thanks

You're welcome.

--
David Empson
dem...@actrix.gen.nz

[qubit]

On 13/07/12 12:37 PM, Lewis wrote:
> In message <jtnlm6$fjk$1...@speranza.aioe.org>

> qubit <qu...@quandoveloce.com> wrote:
>> On 11/07/12 11:51 PM, Lewis wrote:
>>> In message <jtjib9$e84$1...@speranza.aioe.org>
>>> qubit <qu...@quandoveloce.com> wrote:
>>>
>>>> just for the record, A MacBook Pro at this time, does not run three 27
>>>> inch Thunderbolt displays concurrently.
>>>
>>> It runs 2 Thunderbolt and 1 HDMI.
>>>
>>> <http://blog.macsales.com/14241-macbook-pro-15-with-retina-display-can-run-3-external-displays2>
>
>> that's the idea I know. But I was trying to connect A TB display via
>> HDMI.
>

> Yeah, there's no chance that can work. TB is not HDMI, you would need a
> convertor (not an adapter, a converter).

>
>> ALso tried direct HDMI to a plasma TV only, recognised the device
>> but no signal.
>

> That is odd. I know for a fact the MBPr can manage two TB displays and
> an HDMI screen.


I tried connecting just the tv, to test if the cable alone would would
work ( had to take the MBPr to the TV and leave the TB displays on the
desk). I assumed it would be plug and play.