Intel Atom Processor
in [Debian]
|
Prev: j2se on debian
Next: UDF: maximum file/directory limit?
From: Stan Hoeppner on 17 Feb 2010 21:10 Tixy put forth on 2/17/2010 11:11 AM: > On Wed, 2010-02-17 at 08:56 -0800, Mark wrote: > <snip> >> for some reason Lenny reports dual Atom processors even though the >> specs for the machine only list one (??). > <snip> > > I've noticed that as well. The Atom has Hyper-Threading, so it can run > two threads simultaneously on one core; that could explain it. Two Atom processors are dual core processors with HT capability, the 330 and the D510: http://ark.intel.com/Product.aspx?id=35641&processor=330&spec-codes=SLG9Y http://ark.intel.com/Product.aspx?id=43098&processor=D510&spec-codes=SLBLA With HT disabled you'll see two CPUs in /proc/cpuinfo With HT enabled you'll see four CPUs in /proc/cpuinfo The rest of the Atom CPUs, but the Z510, all support HT, so all of those will show 2 CPUs in /proc/cpuinfo with HT enabled. -- Stan -- To UNSUBSCRIBE, email to debian-user-REQUEST(a)lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster(a)lists.debian.org Archive: http://lists.debian.org/4B7C9F47.8050500(a)hardwarefreak.com
From: Stan Hoeppner on 17 Feb 2010 23:30 Vincent Lefevre put forth on 2/17/2010 6:21 AM: > On 2010-02-16 09:52:06 -0600, Stan Hoeppner wrote: >> As a bonus, due to various architectural reasons I won't delve into, >> 32bit binaries will usually run slightly faster than the 64 bit >> cousins, and they'll take up a little bit less disk space. > > No, this depends on the application (and "usually" doesn't mean very > much because applications will depend on what the machine is used > for). And some people would completely disagree with you, e.g.: Vincent, you're quoting me out of context. Apparently you haven't read the entire thread. Or you're misquoting me intentionally. I clearly stated that my comments pertained to a certain application class on this platform. > http://www.phoronix.com/scan.php?page=article&item=ubuntu_32_pae&num=1 These benchmarks are irrelevant to the current discussion. They are on a capable dual core Intel Core Processor, and the application mix is not the same as that of an average Atom user. > There's another point is favor of amd64: floating-point arithmetic. > As SSE is used by default on amd64, FP arithmetic is much cleaner > there in practice. We all know this already (or at least should). However, again, it's irrelevant to _this_ thread. This thread, and my comments, deal with Atom based systems with less than 2GB of RAM. This thread is not about 32bit vs 64bit binary performance in general. It's about 32bit vs 64bit binary performance on the Atom processor and the bulk of applications that users will run on such a platform daily, which basically includes only these two apps: 1. Web brower 2. Email client x86-64 optimizations and performance enhancements will rarely be taken advantage of for this class of machine. FP (SSE/SSE2) isn't going to make a lick of difference. I didn't state 32bit software is better across the board on x64-64 CPUs. I said in _this_ case, for the vast majority of users, 32bit software will have a slight performance advantage, and I'm correct. The vast majority of Atom chips shipped reside in netbooks. The vast majority of netbook owners will never have over 2GB ram and will never run FP heavy applications, or any application mix where a 64bit binary pay additional dividends. Take another stab at misquoting me and listing an irrelevant test case for irrelevant comparison. -- Stan -- To UNSUBSCRIBE, email to debian-user-REQUEST(a)lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster(a)lists.debian.org Archive: http://lists.debian.org/4B7CC0B5.1070304(a)hardwarefreak.com
From: Vincent Lefevre on 18 Feb 2010 09:30
On 2010-02-17 22:23:17 -0600, Stan Hoeppner wrote: > Vincent Lefevre put forth on 2/17/2010 6:21 AM: > > On 2010-02-16 09:52:06 -0600, Stan Hoeppner wrote: > >> As a bonus, due to various architectural reasons I won't delve into, > >> 32bit binaries will usually run slightly faster than the 64 bit > >> cousins, and they'll take up a little bit less disk space. > > > > No, this depends on the application (and "usually" doesn't mean very > > much because applications will depend on what the machine is used > > for). And some people would completely disagree with you, e.g.: > > Vincent, you're quoting me out of context. Apparently you haven't > read the entire thread. Or you're misquoting me intentionally. I > clearly stated that my comments pertained to a certain application > class on this platform. AFAIK nothing has been said about such a certain application class. > > http://www.phoronix.com/scan.php?page=article&item=ubuntu_32_pae&num=1 > > These benchmarks are irrelevant to the current discussion. They are > on a capable dual core Intel Core Processor, I know that the processor is different, but what you said could be interpreted as a general remark on the amd64 architecture. Unfortunately you didn't provide any benchmarks yourself. So, what you said is purely gratuitous. > and the application mix is not the same as that of an average Atom > user. The OP isn't necessarily an "average Atom user". > > There's another point is favor of amd64: floating-point arithmetic. > > As SSE is used by default on amd64, FP arithmetic is much cleaner > > there in practice. > > We all know this already (or at least should). However, again, it's > irrelevant to _this_ thread. Why? > This thread, and my comments, deal with Atom based systems with less > than 2GB of RAM. This thread is not about 32bit vs 64bit binary > performance in general. No, this thread is about answering the OP's question, which is: Which architecture should I use for an Intel Atom Processor? Also, the FP behavior is *not* binary performance. > It's about 32bit vs 64bit binary performance on the Atom processor > and the bulk of applications that users will run on such a platform > daily, which basically includes only these two apps: > > 1. Web brower > 2. Email client The OP did *not* say that he would use only these two applications. Anyway, even a web browser is affected by the x86 FP behavior (at least under Debian), and any user can be affected by it since users don't control scripts from remote web sites. > x86-64 optimizations and performance enhancements will rarely be > taken advantage of for this class of machine. FP (SSE/SSE2) isn't > going to make a lick of difference. Wrong! See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=309797 for instance (this is for Mozilla, but Iceweasel on Debian/stable is affected too -- I could test it). -- Vincent Lef�vre <vincent(a)vinc17.net> - Web: <http://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / Ar�naire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to debian-user-REQUEST(a)lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmaster(a)lists.debian.org Archive: http://lists.debian.org/20100218140533.GI23080(a)prunille.vinc17.org |