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Rainyday

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Dec 28, 2017
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I found this on Quora :

"Apple is using AMD for a reason other then battery life. Apple makes the Macbook pro 2 5k monitor capable by having 4 display port 1.2 channels, Nvidia maxes at 3 channels, so until this is changed Apple might stick with AMD."

Please help me understand this paragraph. Unfortunately, I don't have deep knowledge about video ports and even 'channels' term. I think some sentences not expressed clearly. Beside that, tell me please as a whole is this answer correct and trustable?

Any help would be appreciated.


https://www.quora.com/Is-there-a-MacBook-Pro-2017-with-a-Nvidia-GPU
 
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Brookzy

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In direct response to your query, a graphics card has a fixed number of display outputs that can be used to connect a display. These are called lanes, or "DisplayPort lanes". The AMD chip used in the 15" MacBook Pro has six DisplayPort lanes, each capable (in theory) of driving up to one 4K display.

A single 5K display uses the equivalent of two 4K streams, and thus two DisplayPort lanes*. Thus the 15" MacBook Pro can support its internal display plus up to four external 4K displays or two external 5K displays, using a total of five DisplayPort lanes. The sixth lane remains unused because of the limitations of the number of ports and their capabilities.

Nvidia's chips only have three lanes according to that article, which would only be enough for the internal display plus either two 4K external displays or one external 5K display. Dual 5K display support was a big marketing point for the 15" MacBook Pro and Thunderbolt 3, even if in practice very few people will ever use it.

In response to the general point around AMD vs. Nvidia:
  1. Apple is a difficult customer, demanding highly customised products from its suppliers. Apple and AMD have struck up a good working relationship with common principles. Apple has thus stuck with AMD despite Nvidia seemingly winning the graphics war at the moment.
  2. Apple has signed an agreement with AMD to supply all its graphics chips for the next few years, likely in order to encourage AMD to bend to Apple's demands and also provide very low prices for graphics chips. So a new Mac with an Nvidia chip is unforeseeable for now.
  3. The article is wrong about battery life. The AMD chip in the MacBook Pro uses less than 35W and is incredibly thin. A comparable Nvidia chip would use nearly 85W. That would require a complete re-engineering of the MacBook - that would double its overall power consumption and thus require a way bigger battery, way stronger cooling, and overall it would be a completely different product.
  4. Benchmarks are not everything. Synthetic benchmarks make AMD's chips look worse than they are, and Nvidia's chips look better than they really are.
*At least for now. Future versions of DisplayPort will support a 5K display over a single lane.
 
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toleda

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Jan 20, 2010
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Future versions of DisplayPort will support a 5K display over a single lane.
All current Nvidia graphics cards support DP 1.3/5K+. Apple's issue is Intel/Thunderbolt 3 only supports DP 1.2/4K, same as Thunderbolt 1 and 2. Generations ago, Nvidia (4 displays) chose not to compete with AMD Eyefinity (6 displays) preventing consideration for Mac Pro, MacBookPro and iMac Pro. Simply, Nvidia did not recognize Apple controls the display connector. My opinion, Thunderbolt 4 (DP 1.3) may be the next opportunity for Nvidia.
 
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SteveJUAE

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Aug 14, 2015
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In direct response to your query, a graphics card has a fixed number of display outputs that can be used to connect a display. These are called lanes, or "DisplayPort lanes". The AMD chip used in the 15" MacBook Pro has six DisplayPort lanes, each capable (in theory) of driving up to one 4K display.

A single 5K display uses the equivalent of two 4K streams, and thus two DisplayPort lanes*. Thus the 15" MacBook Pro can support its internal display plus up to four external 4K displays or two external 5K displays, using a total of five DisplayPort lanes. The sixth lane remains unused because of the limitations of the number of ports and their capabilities.

Nvidia's chips only have three lanes according to that article, which would only be enough for the internal display plus either two 4K external displays or one external 5K display. Dual 5K display support was a big marketing point for the 15" MacBook Pro and Thunderbolt 3, even if in practice very few people will ever use it.

In response to the general point around AMD vs. Nvidia:
  1. Apple is a difficult customer, demanding highly customised products from its suppliers. Apple and AMD have struck up a good working relationship with common principles. Apple has thus stuck with AMD despite Nvidia seemingly winning the graphics war at the moment.
  2. Apple has signed an agreement with AMD to supply all its graphics chips for the next few years, likely in order to encourage AMD to bend to Apple's demands and also provide very low prices for graphics chips. So a new Mac with an Nvidia chip is unforeseeable for now.
  3. The article is wrong about battery life. The AMD chip in the MacBook Pro uses less than 35W and is incredibly thin. A comparable Nvidia chip would use nearly 85W. That would require a complete re-engineering of the MacBook - that would double its overall power consumption and thus require a way bigger battery, way stronger cooling, and overall it would be a completely different product.
  4. Benchmarks are not everything. Synthetic benchmarks make AMD's chips look worse than they are, and Nvidia's chips look better than they really are.
*At least for now. Future versions of DisplayPort will support a 5K display over a single lane.

Whilst I generally like this post it sort of evades the chicken and egg scenario of the MBP design

By adopting only USB-C charging the MBP is capped at 100w and by opting for a 45W CPU all the cooling and battery has gone to support that component leaving little choice but to opt for a 35W GPU. If the selection priorities were in that order. Arguably the MBP would of been the same size or smaller even if they had opted for a low power CPU and a higher power GPU and stayed with in 100w

Due to Apples effort to make the new MBP even thinner and striving for quieter laptops what you get is a nice design that is likely to throttle earlier than some which may negate performance gains with a 45W CPU in certain scenarios with a slightly lessor spec low powered GPU but with a reasonable battery life and hence weight

As an example its quite possible to have both a 45w CPU and a 85W GPU and only increase the thickness by 0.06" (1.5mm) and a larger battery with a 0.5lb increase over the MBP (eg Dell Core i7-7700HQ 7th gen + Nvidia GeForce GTX 1050)

Additionally the new low power CPU's mixed with high power GPU arguably can give a more rounded appeal to most considering that by Apples own metric the number of professionals using mac's is very low

It's all about choices and compromises and given Apple majority target audience is not professionals with the size and weight and power plus available components at that time this was Apples solution. As you note the extra external monitor options is largely superfluous for most.
 
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Brookzy

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Whilst I generally like this post it sort of evades the chicken and egg scenario of the MBP design

By adopting only USB-C charging the MBP is capped at 100w and by opting for a 45W CPU all the cooling and battery has gone to support that component leaving little choice but to opt for a 35W GPU. If the selection priorities were in that order. Arguably the MBP would of been the same size or smaller even if they had opted for a low power CPU and a higher power GPU and stayed with in 100w

Due to Apples effort to make the new MBP even thinner and striving for quieter laptops what you get is a nice design that is likely to throttle earlier than some which may negate performance gains with a 45W CPU in certain scenarios with a slightly lessor spec low powered GPU but with a reasonable battery life and hence weight

As an example its quite possible to have both a 45w CPU and a 85W GPU and only increase the thickness by 0.06" (1.5mm) and a larger battery with a 0.5lb increase over the MBP (eg Dell Core i7-7700HQ 7th gen + Nvidia GeForce GTX 1050)

Additionally the new low power CPU's mixed with high power GPU arguably can give a more rounded appeal to most considering that by Apples own metric the number of professionals using mac's is very low

It's all about choices and compromises and given Apple majority target audience is not professionals with the size and weight and power plus available components at that time this was Apples solution
In fairness MagSafe never went above 85W either so it isn't USB-C being the constraint. The AMD chips pack a bigger bunch than they get credit for, especially when combined with properly-optimised software like Final Cut.

But to go down a tier in processor would mean they go dual core, wouldn't it? which would be unthinkable. Very underpowered.

I take your point with the Dell comparison though it is closer to twice as thick than 1.5mm thicker.

I'll gladly criticise the MacBook Pro in many respects, but in terms of horsepower, Apple exceeded expectations when you bear in mind their history and the aims of the MacBook Pro.

The cooling is also streets ahead than previous models. Throttling happens, but it's pretty modest.
 

SteveJUAE

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In fairness MagSafe never went above 85W either so it isn't USB-C being the constraint. The AMD chips pack a bigger bunch than they get credit for, especially when combined with properly-optimised software like Final Cut.

But to go down a tier in processor would mean they go dual core, wouldn't it? which would be unthinkable. Very underpowered.

I take your point with the Dell comparison though it is closer to twice as thick than 1.5mm thicker.

I'll gladly criticise the MacBook Pro in many respects, but in terms of horsepower, Apple exceeded expectations when you bear in mind their history and the aims of the MacBook Pro.

The cooling is also streets ahead than previous models. Throttling happens, but it's pretty modest.

Agreed :)

USB-C is the constraint as there is nothing stopping them producing say 125w Magsafe :)

Final cut shure, but thats a limited set of users

8th gen quad cores were obviously not available when the MBP was designed, but a nice optiion now

Maybe the spec page was wrong on the Dell but it says 11-17mm for 15"XPS and MBP is 15.5mm
 

Brookzy

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May 30, 2010
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Agreed :)

USB-C is the constraint as there is nothing stopping them producing say 125w Magsafe :)

Final cut shure, but thats a limited set of users

8th gen quad cores were obviously not available when the MBP was designed, but a nice optiion now

Maybe the spec page was wrong on the Dell but it says 11-17mm for 15"XPS and MBP is 15.5mm
I'm convinced Dell just lie... :p

macbook_pro_vs_xps_15-3.jpg
 

Strelok

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Jun 6, 2017
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It seems the AMD cards actually perform better in most "productivity" apps on macOS. They are more OpenCL/OpenGL based, where Nvidia seems to struggle quite a bit since they focus on CUDA.
 

leman

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Oct 14, 2008
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By adopting only USB-C charging the MBP is capped at 100w and by opting for a 45W CPU all the cooling and battery has gone to support that component leaving little choice but to opt for a 35W GPU. If the selection priorities were in that order. Arguably the MBP would of been the same size or smaller even if they had opted for a low power CPU and a higher power GPU and stayed with in 100w

As we have discussed in a number of other threads, this is a moot point since its the power design Apple always used with the MBP (and with the PoweBrook before). Actually, USB-C provides higher charging power than any previous iteration of the MBP. And there is nothing preventing Apple from rolling a proprietary higher-wattage extension to USB power delivery that would only work with certified chargers/cables.

Due to Apples effort to make the new MBP even thinner and striving for quieter laptops what you get is a nice design that is likely to throttle earlier than some which may negate performance gains with a 45W CPU in certain scenarios with a slightly lessor spec low powered GPU but with a reasonable battery life and hence weight

Again, this is the design Apple was pursuing for more then a decade now, nothing exclusive to the last MBP. Not to mention that the CPU doesn't throttle. Apple's 15" MBP has traditionally provided highest CPU performance of any laptop using consumer-class chips, and this is still true with the current design.

As an example its quite possible to have both a 45w CPU and a 85W GPU and only increase the thickness by 0.06" (1.5mm) and a larger battery with a 0.5lb increase over the MBP (eg Dell Core i7-7700HQ 7th gen + Nvidia GeForce GTX 1050)

The 1050 GTX is around 50 Watt, not 85, and the Dell doesn't match sustained CPU performance of the MBP — it throttles where the MBP doesn't. Sources (check out sustained Cinebench test):

https://www.notebookcheck.com/Test-Dell-XPS-15-2017-9560-i7-7700HQ-UHD-Laptop.203500.0.html
https://www.notebookcheck.com/Test-Dell-XPS-15-2017-9560-i7-7700HQ-UHD-Laptop.203500.0.html


Additionally the new low power CPU's mixed with high power GPU arguably can give a more rounded appeal to most considering that by Apples own metric the number of professionals using mac's is very low

Apple's design choice for the 15" MBP is highest possible on-demand CPU performance, which they have consistently delivered over last 15+ years. There might be applications where trading CPU for GPU makes sense, but its not the design Apple goes for.
 
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leman

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I'm convinced Dell just lie... :p

Oh my. Its a shame we don't have an XPS 15, would have loved to measure it properly. It seems like Dells 17mm are only the side, without the tapered bottom..
[doublepost=1514552086][/doublepost]
As above plus OpenCL. ;)

OpenCL is dead on Apple's platform. They haven't updated it for years. Its all about Metal now. This entire situation is a shame, since OpenCL is Apple's brainchild to begin with. But instead of properly promoting it and using their resources, they just gave it away to a less competent/passionate group and the resulting fragmentation is what we have now. Nvidia was smart about using the overall confusion to promote their own API, which was much more convenient to use (even though Nvidia's hardware is strictly speaking less advanced than AMDs).
 
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SteveJUAE

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As we have discussed in a number of other threads, this is a moot point since its the power design Apple always used with the MBP (and with the PoweBrook before). Actually, USB-C provides higher charging power than any previous iteration of the MBP. And there is nothing preventing Apple from rolling a proprietary higher-wattage extension to USB power delivery that would only work with certified chargers/cables.



Again, this is the design Apple was pursuing for more then a decade now, nothing exclusive to the last MBP. Not to mention that the CPU doesn't throttle. Apple's 15" MBP has traditionally provided highest CPU performance of any laptop using consumer-class chips, and this is still true with the current design.



The 1050 GTX is around 50 Watt, not 85, and the Dell doesn't match sustained CPU performance of the MBP — it throttles where the MBP doesn't. Sources (check out sustained Cinebench test):

https://www.notebookcheck.com/Test-Dell-XPS-15-2017-9560-i7-7700HQ-UHD-Laptop.203500.0.html
https://www.notebookcheck.com/Test-Dell-XPS-15-2017-9560-i7-7700HQ-UHD-Laptop.203500.0.html




Apple's design choice for the 15" MBP is highest possible on-demand CPU performance, which they have consistently delivered over last 15+ years. There might be applications where trading CPU for GPU makes sense, but its not the design Apple goes for.
Leman you really need to stop this sales rehetoric pitch

Apple like any other OEM makes certain design choices and only they know why

Just because they have done this or that for X years is no evidence that they could of not selected other options if they so wished :rolleyes:

USB compliant devices are capped currently at 100W simply due to pin spacing Apple can opt for any proprietory power connection if they so desired, it's not a moot point they chose it.

The Dell example was used simply about size/weight and not about performance comparisons or price :rolleyes: although we think Dell maybe cheating on thier measurements :D

If you think your MBP does not throttle in certain scenarios then you must of got one off planet

My bad , agreed the notebook GTX1050 is around 50w opposed to desktop around 70w

Apple' has clearly targeted its audience which by far is non professionals, sure it's a good fit for a few professions especially those can take advantage of a couple of highly optimised software that help to make up some design shortfalls.

This does not detract from the fact it still is a nice expensive premium laptop for those that prefer macOS. But its clear in selecting more middle ground appeal for non professional they have alienated some professionals and the much higher entry point has curbed some wannabe mac owners
 
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