Jul 24, 2013

New monitor and old notebook

When I arrived at the office today there was a new monitor on my desk. Acer PB278Q 27” 16:9 2560 x 1440 WQHD LED-backlit Monitor. It is very nice monitor.

My notebook uses the second generation Core i7 processor i7-2620M. The embedded Intel HD Graphics 3000 officially has as maximum resolution 1900x1200 for 60 Hz refresh rate.

If using lower refresh rate, it is possible to use higher resolution. One good source of information is the page:


I was not able to use more than 40 Hz as refresh rate when they say 55 Hz worked with Intel HD Graphics 3000. I can set modes up to 44 Hz but then the image is not stable and goes black for one second some times.

What I did:

$ gtf 2560 1440 40

  # 2560x1440 @ 40.00 Hz (GTF) hsync: 58.92 kHz; pclk: 200.80 MHz
  Modeline "2560x1440_40.00"  200.80  2560 2712 2984 3408  1440 1441 1444 1473  -HSync +Vsync


$ xrandr --newmode "2560x1440_40.00"  200.80  2560 2712 2984 3408  1440 1441 1444 1473  -HSync +Vsync

$ xrandr --addmode HDMI3 "2560x1440_40.00"

$ xrandr --output HDMI3 --mode "2560x1440_40.00"

But I would like to increase the refresh rate. Do you have the 55Hz ModeLine for Acer PB278Q?

Also, how can I tell Gnome display settings about the new resolution? See my question here.

See how cool it is! :-)

Jul 23, 2013

CCFinderX, the new CCFinder

Finding code clones is far from trivial. For a nice explanation about the challenges of finding clones in source code, I suggest reading: "Comparison and evaluation of code clone detection techniques and tools: a qualitative approach". You can start by reading sections 2 and 6.

There are at least two tools with source code available under permissive free software licenses. Deckard and CCFinderX. CCFinderX is an evolution of CCFinder, made by the same author.

Deckard is easy to build and test, however CCFinder was not. For Linux users, I made a fork from gpoo/ccfinderx, and made some changes to simplify the build on Linux. The main change is to separate the core from the GUI. I have now two repositories:




Both are clones from gpoo/ccfinderx, but I've spited things. At the moment the GUI do not work but you can build CCFinderX-core without wired OpenJDK dependencies. And it works producing textual output. My goal with this repositories is provide source code that can be compiled, packed, and distributed.