2015 15" Iris Pro vs 2017 13" ntb Iris Plus 640

[project_2501]

Which will better drive a 4k display at 60hz over DisplayPort?

2015 MBP 15" Iris Pro vs 2017 MBP 13" ntb Iris Plus 640 ?

Looking at the GPU itself they seem very similar in architecture. The 2015's Iris Pro actually has double the eDRAM. Will the greater thermal envelope allow the 2015 to drive the 4K more comfortably?

I know Apple advertsies both of these as being able to drive multiple 4K displays, but the 2015 13" Iris 6100 could only do it with stuttering performance so I don't believe their marketing. My own experience of the 2017 nTB has been that it does drive the 4K display but it overheats within minutes.

I don' play games but I do watch video and hardware decode of codecs can be useful. I understand the Iris Pro from 2015 does hardware decode vp9 and h265 but might not be able to encode them, hence that will done in software on the main CPU.

 

[Freyqq]

Benchmarks:
https://www.notebookcheck.net/Intel-Iris-Pro-Graphics-5200.90965.0.html
https://www.notebookcheck.net/Intel-Iris-Plus-Graphics-640.190371.0.html

They look like they're about the same speed with some benchmarks advantaging the 15" and some the 13". So, i'd probably give the some advantage to the 640 since it supports new codecs in addition to being about the same raw speed.

However, the 15" wins hands down in CPU with a quad core 45w processor vs a dual core 15w processor in the 13".

 

[MH01]

The 2015 , mac book pro does not come with dedicated graphics? I'd be looking at that model , as a refurb

 

[Samuelsan2001]

Which will better drive a 4k display at 60hz over DisplayPort?

2015 MBP 15" Iris Pro vs 2017 MBP 13" ntb Iris Plus 640 ?

Looking at the GPU itself they seem very similar in architecture. The 2015's Iris Pro actually has double the eDRAM. Will the greater thermal envelope allow the 2015 to drive the 4K more comfortably?

I know Apple advertsies both of these as being able to drive multiple 4K displays, but the 2015 13" Iris 6100 could only do it with stuttering performance so I don't believe their marketing. My own experience of the 2017 nTB has been that it does drive the 4K display but it overheats within minutes.

I don' play games but I do watch video and hardware decode of codecs can be useful. I understand the Iris Pro from 2015 does hardware decode vp9 and h265 but might not be able to encode them, hence that will done in software on the main CPU.

Hardware decoding of h265 did not arrive until Kaby lake in the 2017.

 

[project_2501]

Hardware decoding of h265 did not arrive until Kaby lake in the 2017.

according to wikipedia Broadwell could decode, Skylake could encode and decode.
https://en.wikipedia.org/wiki/Intel_HD_and_Iris_Graphics#Hardware-accelerated_algorithms