[=shadowphiar;60387]
I realise that using OpenGL in both cases is technically a fairer test of the OS and drivers, but I suspect the choice most people are actually making is whether to use OpenGL on Mac OS or Direct3D on Windows.
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That’s obviously their individual choice and at present Direct3D on Windows has some advantages as it offers more features both in terms of effects for end-users and optimisation opportunities for developers. OpenGL 4.3 is available on Windows (and some Linux drivers too I believe) and is broadly equivalent, but OS X doesn’t have support for that version of OpenGL yet. Features like compute shaders, read-write buffers in shaders and several OpenGL specific extensions to reduce state-setting were only introduced in OpenGL 4.2 or 4.3 and without them we can’t implement all the same features of D3D11 or achieve the same performance.
[=shadowphiar;60387]
What are the Windows results for that test on that hardware without the -opengl argument?
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I was curious too, so they I checked and they are:
Win8.1/NV335.23/D3D11: BasicCode: ~44fps/22.5ms, RealisticRendering: ~41fps/24.5ms
Win8.1/NV335.23/OpenGL4: BasicCode: ~38fps/26ms, RealisticRendering: ~34fps/29.5ms
As you can see with Shader Model 5 rendering features we actually render slower in these projects, not 2-3 times faster, because we are performing additional
render passes and using higher-quality effects which are necessarily slower. We are still working on the OpenGL 4.3+ render path so it is slower in this preview build than the D3D11 renderer but it should improve as we go.
[=jmorante;61310]
I was just more concerned with the discrepancy between Windows and OS X performance in general. <snip>. . .</snip>
I know OS X is not historically great at graphics, with their fairly poor OpenGL driver support and all.
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As you can see from the numbers I posted there’s not any significant overall difference anymore between the performance of OpenGL <= 4.1 features & extensions running on OS X versus Windows for the Nvidia GPUs in newer Macs. That’s a massive improvement from where Apple were in 2005 at the tail-end of PPC and transition to Intel. That we’d now only be complaining about an occasional driver bug and being a few OpenGL versions behind was inconceivable back then. The days of truly bad OpenGL support appear to be behind us and I know the driver teams at Apple & the OEMs are working extremely hard to ensure it continues to improve.
[=jmorante;61310]
Just wondering if, in the future, the new will be as great of a development machine as a similar Windows Desktop, or if driver and platform differences will always result in Windows being the better development experience. At least, for the foreseeable future.
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I can tell you that a new is definitely a very good development experience on OS X right now - but I don’t have Windows installed on it to do the same comparison as above. Running the Windows version might be faster - I just don’t know and from experience these things do vary from one GPU vendor to the next. What is definitely true is that D3D11 under Windows presently supports more rendering features than OS X’s OpenGL 4.1. We have asked them for the features we need and when Apple update OS X’s OpenGL that will change, but I’ve no better idea than you as to if or when they may do that.
[=VFe;61435]
yeah the issue isn’t the hardware per se, we know it’s weaker.
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The hardware Apple supply tends to be in the upper-mid-range or lower-high-end, depending on model. It isn’t weaker than PC you just have to be careful that you don’t compare Apple’s & Oranges 
Notably all the iMacs, at least from the G5 iMac onward, have used laptop GPUs which are definitely less performant than their desktop cousins and it is very easy to mistake them for the same and then wonder why the iMac is so much slower.
[=VFe;61435]
The issue is that if i boot windows on the same exact machine I see nearly double to triple the performance vs staying in OSX.
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Since that is clearly not borne out by my example above I’d really like to know your machine’s specification, the projects you are experiencing this in and what the performance figures you are seeing. If you could post a question on the AnswerHub with your Mac’s specifications (a summary of the Model, GPU, CPU, Memory & OS from System Profiler is what I’d really need) along with an Epic sample project that demonstrates the problem and the performance numbers like I’ve quoted above then I can start looking into this as a specific test case. You never know, there could be an honest bug or performance problem in our code or the GPU driver for your machine that can be fixed or worked around.
[=VFe;61435]
OSX version is for all intents and purposes unusable.
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I have to strongly disagree with this - I’m working on UE4 OS X every day and in all the tests we’ve done here we aren’t seeing the huge performance gulf you are reporting. I know that you all want the OS X version to be identical to the Windows D3D11/SM5 render path. So do I. Unfortunately it is a bit more than unfair to criticise us for not having delivered it - at present OS X doesn’t have the tools.