Feature changed by: Rodney Donovan (rrdonovan) Feature #310987, revision 4 Title: Add Intel Atom as a specific architecture openSUSE Distribution: Unconfirmed Priority Requester: Important Requested by: Jiri Dluhos (jdluhos) Partner organization: openSUSE.org Description: Atom processors, currently very popular in lightweight devices, behave very differently from common Intel/AMD processors; although they can execute code optimized for common x86 or x86-64, they don't run it much efficiently. Because they are not that fast, every cycle counts. I believe it would be useful to consider them a separate sub- architecture that deserves its own set of compilation options. Discussion: #1: Robert Davies (robopensuse) (2010-12-19 18:04:57) Are there any real world application benchmark figures to show the benefit of such an optimisation? My openSUSE experiments with old machines, showed KDE4 to be useable even on a dual 450 Mhz with 512MB RAM, but poor with a faster CPU and 256 MB RAM. With Google I found a 21% floating point boost on Sci Tech, out of using the most modern SSE instructions, but that likely applies similarly to other modern CPUs (not just Atom sub-arch). FWIW I am somewhat skeptical of compile optimisations making large enough difference to be worthwhile for a couple of reasons. Firstly, the Atom's architecture is simple (deliberately), rather than out of order execution and pre-fetch avoiding memory stalls, it uses HT to have the CPU do useful work on memory stalls; which means to maximise CPU throughput you need multiple threads or processes running. Secondly, over time there's been numerous "Compile Optiomised" distro's eg) Revhat, and older distro's were slow to move to pentium or even i686 code. The people who developed fit pc, orginally used Gento optimised for AMD Geode (performance reasons cited), but dropped that in favour of Ubuntu, which they have stuck wiith on fit pc2 which uses an Atom CPU. Basically they have sacrificed compile options in favour of a generic, more popular distribution. + #2: Rodney Donovan (rrdonovan) (2010-12-24 16:53:23) + I have an Asus Eee PC with the N270 32 bit CPU and intel graphics. It + had some linux on it but I replaced it with openSUSE. It runs fine for + the most part. Of course, I replaced the 4 gig SSD with a 16 gig SSD. I + also removed the 1 gig ram and replaced it with 2 gig ram. There is no + swap. I also installed Virtual Box and have Windows XP on a seperate + USB 300 gig HD. Yes, it is a little slow running both OSs at the same + time. But It work well enough to get things done. Hmmm, I next built a + mini PC using Intels 330 dual core processor with Nvidia ION graphics, + 2 gig of ram, and 2 striped 150 gig HDs in a Antec mini skeleton case. + Performance is much, much improved. I can have SUSE running something + while editing files on MS Office (my university demands this). Any way, + I plan to get more memory and an 802.11n card to replace the g that is + presently installed. I watch movies on my 22 inch screen. Very nice + indeed. Now if you can supposedly optimize for the Atom, great! There + are many users out there that would like to move to Linux. Other than + that, My next project is an AMD 6 core monster to serve as my homes + main server with the rest of us as clients using LTPS. Continue the + good work and while your at it, Guard my Beloved Lizard from those who + would harm him lest you encounter my wrath...... + Master Rod -- openSUSE Feature: https://features.opensuse.org/310987

Feature changed by: Tomáš Chvátal (scarabeus_iv) Feature #310987, revision 6 Title: Add Intel Atom as a specific architecture - openSUSE Distribution: New + openSUSE Distribution: Rejected by Tomáš Chvátal (scarabeus_iv) + reject reason: This would consume too much resources. Thus no special + targeting for atom machines. Priority Requester: Important Requested by: Jiri Dluhos (jdluhos) Partner organization: openSUSE.org Description: Atom processors, currently very popular in lightweight devices, behave very differently from common Intel/AMD processors; although they can execute code optimized for common x86 or x86-64, they don't run it much efficiently. Because they are not that fast, every cycle counts. I believe it would be useful to consider them a separate sub- architecture that deserves its own set of compilation options. Discussion: #1: Robert Davies (robopensuse) (2010-12-19 18:04:57) Are there any real world application benchmark figures to show the benefit of such an optimisation? My openSUSE experiments with old machines, showed KDE4 to be useable even on a dual 450 Mhz with 512MB RAM, but poor with a faster CPU and 256 MB RAM. With Google I found a 21% floating point boost on Sci Tech, out of using the most modern SSE instructions, but that likely applies similarly to other modern CPUs (not just Atom sub-arch). FWIW I am somewhat skeptical of compile optimisations making large enough difference to be worthwhile for a couple of reasons. Firstly, the Atom's architecture is simple (deliberately), rather than out of order execution and pre-fetch avoiding memory stalls, it uses HT to have the CPU do useful work on memory stalls; which means to maximise CPU throughput you need multiple threads or processes running. Secondly, over time there's been numerous "Compile Optiomised" distro's eg) Revhat, and older distro's were slow to move to pentium or even i686 code. The people who developed fit pc, orginally used Gento optimised for AMD Geode (performance reasons cited), but dropped that in favour of Ubuntu, which they have stuck wiith on fit pc2 which uses an Atom CPU. Basically they have sacrificed compile options in favour of a generic, more popular distribution. #2: Rodney Donovan (rrdonovan) (2010-12-24 16:53:23) I have an Asus Eee PC with the N270 32 bit CPU and intel graphics. It had some linux on it but I replaced it with openSUSE. It runs fine for the most part. Of course, I replaced the 4 gig SSD with a 16 gig SSD. I also removed the 1 gig ram and replaced it with 2 gig ram. There is no swap. I also installed Virtual Box and have Windows XP on a seperate USB 300 gig HD. Yes, it is a little slow running both OSs at the same time. But It work well enough to get things done. Hmmm, I next built a mini PC using Intels 330 dual core processor with Nvidia ION graphics, 2 gig of ram, and 2 striped 150 gig HDs in a Antec mini skeleton case. Performance is much, much improved. I can have SUSE running something while editing files on MS Office (my university demands this). Any way, I plan to get more memory and an 802.11n card to replace the g that is presently installed. I watch movies on my 22 inch screen. Very nice indeed. Now if you can supposedly optimize for the Atom, great! There are many users out there that would like to move to Linux. Other than that, My next project is an AMD 6 core monster to serve as my homes main server with the rest of us as clients using LTPS. Continue the good work and while your at it, Guard my Beloved Lizard from those who would harm him lest you encounter my wrath...... Master Rod -- openSUSE Feature: https://features.opensuse.org/310987