View Full Version : OpenGL/WebGL performance on HP Slate
03-02-2011, 07:37 PM
There does not seem to be hardware acceleration on the HP Slate for OpenGL or WebGL. The Intel chip apparently has a PowerVR SGX core of the same family as the iPad but when I run the Realtech VR OpenGL benchmark I get about 4Hz on the HP and about 50Hz on the iPad. I am guessing that the app on the iPad is running OpenGL ES and on the HP it is running regular OpenGL since it is Windows 7. Could it be that there simply are not hardware accelerated OpenGL PowerVR drivers for the HP Slate yet? Does anyone know where I could track one down? I have the latest drivers from Intel btw, HP has no driver support on their website yet.
03-03-2011, 09:13 PM
The iPad uses an Imagination Technologies PowerVR GPU core with mature, well-optimized drivers (I think, written by Apple) that came from the iPhone. Not Intel.
The HP slate uses the Intel "Graphics Media Accelerator 500"...which is also a PowerVR GPU core - the same one as the iPad...but buried inside a different chip.
The PowerVR GPU can have between one and 16 cores...I don't know how many are in the iPad and the Slate...so that could mean anything up to a 16x performance difference. However, I kinda doubt that because the iPad-2 claims a 9x graphics speedup over the iPad-1, also using a PowerVR GPU at only twice the clock rate of the iPad-1. So presumably the majority of that speedup comes from having more cores than the iPad-1. If iPad-2 has 16 GPU cores - then the iPad-1 can't have more than four - so even if the Slate only had one - unless it's running at a much lower clock rate (which is possible) that's not enough to account for a 10x slower result.
Sadly, the other difference is Intel drivers versus Apple drivers.
Intel's history of graphics chip driver competence is just terrible...and their support for OpenGL has historically been abysmal.
So it's entirely possible to see a 10x difference. Between different clock rates, different numbers of cores, a different CPU driving it...and Apple versus Intel drivers...there is plenty of scope for a 10x difference.
Also - what browsers are you running? I presume Safari on the iPad...Chrome or Firefox on the Slate? If you're running Chrome then both browsers are using "WebKit" - so probably the browser performance will be kinda similar...if you're running Firefox then it may be that something in your application is running slower.
Personally, I won't buy anything with an Intel graphics chip/driver inside...unless it's something that I know I'll definitely never want to do graphics on. Intel make great CPU's and other chips - but somehow they always dramatically under-perform when it comes to graphics.
03-04-2011, 10:41 AM
The Realtech VR OpenGL benchmark was running in what I assume is a "native" application on both the Slate (Windows 7, assuming OpenGL) and iPad (not sure if it would be OpenGL or OpenGL ES). I also ran some WebGL apps on the Slate using Chrome and saw similarly poor performance results. The new iPad 2 has the PowerVR XT series chip which does support more cores and the cores are also physically smaller so that should allow more cores, less power per core, and higher throughput. It is interesting to note that the new XT cores appear to be slightly slower per core, but they make up for it by packing more on a chip.
When I run on the Slate I notice that the RealTech app only sees the GDI Generic driver which is a software-only driver supplied I think by Microsoft. So I am keeping my fingers crossed that Intel will release SOMETHING for their chipset.
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