On Jul 21, 2016, at 10:56 AM, Markus KARG <mar...@headcrashing.eu> wrote:
The limiting factor is the single-thread architecture of rather all parts of JavaFX. The
only real difference you see between machines is not correlating with neither number of
CPU cores nor GPU cores, but only with CPU frequency, roughly spoken. Short term fixes
will only provide little improvement, by optimizing the critical execution path (i. e.
produce hot spot histogram using a profiler), for example improvement clipping, caching,
etc. Huge performance optimizations need an architectural change within JavaFX's
"scenegraph-to-bitmapframe" (a.k.a. rendering) pipeline to use parallel
execution in lots of places. Typical design patterns would be parallel iterations,
work-stealing executors, fibers (a.k.a cooperative multi-threading, a.k.a
CompletableFuture), and last but not least partitioned rendering (a.k.a tiled rendering).
I am pretty sure you can add a lot more ideas to the list and produce great
performance, scaling linearly with number of CPU cores / GPU cores, but this
somes at a cost: Risk to introduce hard to track bugs, and needed manpower.
If somebody has at least a lot of free spare time, I am pretty sure Kevin could
easily provide a huge set of work items in this area. :-)
-Markus
-----Original Message-----
From: openjfx-dev [mailto:openjfx-dev-boun...@openjdk.java.net] On Behalf Of
Dr. Michael Paus
Sent: Donnerstag, 21. Juli 2016 12:07
To: openjfx-dev@openjdk.java.net
Subject: Re: Scene graph performance
Hi Felix,
I have written various tests like the ones you use in FXMark and I have
obtained similar results. I have even tried to substitute 2D shapes by using 3D
MeshViews in the hope that this would give better performance but the results
were not that good. Of course all this depends on the specific test case but in
general I see that a JavaFX application which makes heavy use of graphics
animations is completely CPU-bounded.
The maximum performance is reached when one CPU/Core is at 100%.
The performance of your graphics hardware seems to be almost irrelevant.
I could for example run four instances of the same test with almost the same
performance at the same time. In this case all 4 cores of my machine were at
100%. This proves that the graphics hardware is not the limiting factor. My
machine is a MacBook Pro with Retina graphics and a dedicated NVidia graphics
card which is already a couple of years old and certainly not playing in the
same league as your high-power card.
I myself have not yet found a way to really speed up the graphics performance
and I am a little bit frustrated because of that. But it is not only the
general graphic performance which is a problem. There are also a lot of other
pitfalls into which you can stumble and which can bring your animations to a
halt or even crash your system. Zooming for example is one of these issues.
I would like to have some exchange on these issues and how to best address them
but my impression so far is that there are only very view people interested in
that. (I hope someone can prove me wrong on this :-)
Michael
Am 20.07.16 um 04:14 schrieb Felix Bembrick:
Having written and tested FXMark on various platforms and devices, one thing has really struck me as quite "odd".
I started work on FXMark as a kind of side project a while ago and, at the time, my
machine was powerful but not "super powerful".
So when I purchased a new machine with just about the highest specs available
including 2 x Xeon CPUs and (especially) 4 x NVIDIA GTX Titan X GPUs in SLI
mode, I was naturally expecting to see significant performance improvements
when I ran FXMark on this machine.
But to my surprise, and disappointment, the scene graph animations ran almost
NO faster whatsoever!
So then I decided to try FXMark on my wife's entry-level Dell i5 PC with a
rudimentary (single) GPU and, guess what - almost the same level of performance
(i.e. FPS and smoothness etc.) was achieved on this considerably less powerful
machine (in terms of both CPU and GPU).
So, it seems there is some kind of "performance wall" that limits the rendering
speed of the scene graph (and this is with full speed animations enabled).
What is the nature of this "wall"? Is it simply that the rendering pipeline is
not making efficient use of the GPU? Is too much being done on the CPU?
Whatever the cause, I really think it needs to be addressed.
If I can't get better performance out of a machine that scores in the top 0.01%
of all machine in the world in the 3DMark Index than an entry level PC, isn't
this a MAJOR issue for JavaFX?
Blessings,
Felix
