Posts Tagged ‘hardware’
Intel announces AVX2
By chys on June 14th, 2011The documentation is available for download.
The instruction set war is still there – Intel still doesn’t plan to support many XOP features of AMD; also Intel still plans to use FMA3 while AMD uses FMA4. Nevertheless, this time Intel is at least not making the war even worse. In addition to extending most SSE2/SSE3/SSE4 instructions to 256 bits (this is no surprise), they copied BMI (with an extension called BMI2) and CVT16 from AMD. If I recall correctly, Intel had never copied so many instructions from AMD at once, with the notable exception of x86-64.
CPU Frequency Governor
By chys on May 21st, 2010Kernel documentation recommends “conservative” for laptops, citing latency reasons.
However, Intel explicitly recommends “ondemand” in its powertop. So does at least one Intel kernel developer.
OK. I have been using “conservative.” I decide to switch to “ondemand” from now on.
gspca in Linux 2.6.27
By chys on January 9th, 2009only works with v4l2, but not v4l. So it can lead to problems – programs using v4l gives strange pictures as well as annoying error messages.
My webcam worked with gspcav1 and Linux 2.6.26, but it failed in Linux 2.6.27 (with its in-kernel gspca drivers):
>>cmcapture err -1 cvsync err : Invalid argument cmcapture: Invalid argument
Solution: Install libv4l, and use a command like this:LD_PRELOAD=/usr/lib/libv4l/v4l2convert.so skype.
Reference
Linux kernel bug #11860.
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.
