You forgot an important info: RAM configuration and speed
Thanks. I updated the original post to include the memory & storage info.
Doesn't look wrong to me. Your system uses only singlechannel DDR3-1333. My HD3000 gained +33% in Cinebench 11.5 going from DDR3-1333 singlechannel to dualchannel. Also your iGPU Turbo clocks only up to 950 Mhz.
I'll try populating the second DIMM and see what the improvement is.
When I use GPU-Z and watch the GPU clock, I don't see it going above 650 MHz. Also, what is a good OpenGL 3D benchmarking tool that I can use to compare scores with other motherboards using HD 4000? Furmark doesn't seem to have a good reputation. Cinebench doesn't seem to stress it enough.
My app tries to render 1080p60 video full screen on two displays (HDMI & DP) and it can only do 15 fps using OpenGL. When I use DirectX as renderer, I can do 60 easily on both displays.
Is this disparity because of Intel's driver issues or motherboard issues? Or is this the best Intel integrated graphics can do for OpenGL rendering?
3570k-HD4000 1150 Mhz, DDR3 1600 dualchannel reaches 21 points in Cinebench 11.5. Let's say dualchannel improves your score by 33%, then you should score around 15 fps. You can go to notebookcheck.com and search for HD4000 notebooks, there are lots of Cinebench 11.5 results available with dualchannel or singlechannel. Here: http://www.notebookcheck.net/Intel-HD-Graphics-4000.69168.0.html
Below there is a list with Cinebench 11.5 results.
15 fps (assuming you get +33% with dualchannel) for a 950 Mhz HD4000 doesn't look wrong to me. With DDR3-1600 RAM you could gain another 5% or so. For a better OpenGL performance you should try 15.28 drivers. These drivers are not faster in Cinebench 11.5 but in most OpenGL games and supports OpenGL 4.0.
"My app tries to render 1080p60 video full screen on two displays (HDMI & DP) and it can only do 15 fps using OpenGL. When I use DirectX as renderer, I can do 60 easily on both displays."
What app are you refering to? Where can I get a copy?