Josh,<br><br>The Pentium-M supports the P4 instruction set, but some instructions which are very "efficient" on the P4 are rather "inefficient" in the P-M.<br>So code optimised for the P4 may run slower than code optimised for the P3.<br>I think there's support for the P-M in GCC, though I don't know from which version on.<br><br>BTW: I was not aware to have replied in private to you - will reply to everyone from now on (I blame it on the clunky mail.com interface ;-).<br><br>The floating mode may indeed bite you - as I develop, compile and run under Linux (Ubuntu), I'm afraid I cannot be of much help to you there...<br><br>CU, JDO<br> <div> <br> <blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;">----- Original Message -----<br> From: "Josh Scholar" <joshscholar@nightstudies.net><br> To: "Jan Doornaert" <jan.doornaert@programmer.net><br> Subject: Re: Pentium M and P4 question / and a failed test<br> Date: Mon, 1 Oct 2007 15:25:36 -0700<br> <br> <br><br></jan.doornaert@programmer.net></joshscholar@nightstudies.net><div><span class="gmail_quote">On 10/1/07, <b class="gmail_sendername">Jan Doornaert</b> <<a href="mailto:jan.doornaert@programmer.net">jan.doornaert@programmer.net</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div> Josh,<br><br>The Pentium-M is derived from the PIII core, with some features of the P4 added (like SSE2). For more technical info: <a href="http://www.anandtech.com/showdoc.aspx?i=1800&p=1" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)"> http://www.anandtech.com/showdoc.aspx?i=1800&p=1</a><br><br>As for the long build time: if it's not the processor (Banias? Dothan? GHz?) that's throttling performance, it probably is the (lack of) memory.<br>How much is there - and how much is actually useable (subtract video memory for shared memory cards!)? <br> <br>CU, JDO<br><br></div></blockquote><br>Thank you for your answer.  According to the docs I have the Pentium M has the same instruction set as the Pentium 4.  I thought that maybe the Pentium 4 code was using the new instructions that the P M also has..  But maybe that's not what the optimization consists of, maybe it's a matter of optimizing the pipeline or something. <br><br>As for the long build, the problem was that sys-internal's Process Explorer, for some reason decided not to count the time that the processor was spending in the MSys shell and subprocesses.  So while I thought the processor was only half busy, it was really reporting that half of the processor usage was in FireFox (wasting cycles on flash adverts and javascript). So that must have doubled my build times. <br><br>I have more questions, but I should probably post them on the list.<br><br>One weirdness is that it's my understanding the GCC expects the processor to be in 80 bit float mode (not rounding till store) but I'm driving GMP from a Visual C program, and Visual C sets the mode to 64 bit float mode.  I wonder if that (calling GCC compiled routines from Visual C programs) can cause any problems in GMP.  <br><br>Josh Scholar<br><div><br></div></div> </blockquote> </div> <BR> -- <div>We've Got Your Name at <a href="http://www.mail.com/?utm_source=mail_sent_footer&utm_medium=email&utm_term=070621&utm_content=textlink&utm_campaign=we_got_your_name"target="_blank">Mail.com</a><br> Get a <b>FREE</b> E-mail Account Today - Choose From 100+ Domains</div>