X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f From: Rugxulo Newsgroups: comp.os.msdos.djgpp Subject: Re: PB on CPU Atom Date: Thu, 25 Nov 2010 14:25:53 -0800 (PST) Organization: http://groups.google.com Lines: 44 Message-ID: References: <4e67d035-8f32-4e9e-a78c-2370909f9ffb AT k11g2000vbf DOT googlegroups DOT com> NNTP-Posting-Host: 65.13.115.246 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: posting.google.com 1290723954 17471 127.0.0.1 (25 Nov 2010 22:25:54 GMT) X-Complaints-To: groups-abuse AT google DOT com NNTP-Posting-Date: Thu, 25 Nov 2010 22:25:54 +0000 (UTC) Complaints-To: groups-abuse AT google DOT com Injection-Info: 12g2000prq.googlegroups.com; posting-host=65.13.115.246; posting-account=p5rsXQoAAAB8KPnVlgg9E_vlm2dvVhfO User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.7 (KHTML, like Gecko) Chrome/7.0.517.44 Safari/534.7,gzip(gfe) Bytes: 3329 To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Hi, note that I don't have any Atoms nor am I a professional programmer, but .... On Nov 25, 1:39=A0am, philippe wrote: > > When I try my program on a CPU ATOM N270 @ 1,6Ghz, The program is very > slow. Exemple : I Copy 32000 value in memory. On a cpu Celerom M > @1,6Ghz it take 270 us and on ATOM it take 2856 us. My OS is FreeDos. > the program is compiled with djgpp. > Have you got an idea ? http://en.wikipedia.org/wiki/Intel_atom http://ark.intel.com/Product.aspx?id=3D36331 All I remember hearing was everybody comparing it to the 486 (in-order execution), no superscalar, no out-of-order, just vaguely "slow" ("fast P3 speeds at best"). At least that's what I heard, so I could be wrong. Some of the newer ones are allegedly better, but again, they aren't like typical desktop x86 processors, hence they don't act like it. More specifically, Atom support in GCC was only officially added in 4.5.0, which DJGPP doesn't have. By default DJGPP (still) uses - mtune=3Dpentium (aka, i586), which maybe isn't that ideal. However, having said that, I'd be extremely surprised if -mtune=3Di486 did much of anything, if at all, esp. for your Atom. Seems GCC never cared too too much about 486 (alignment only?) and certainly cares less nowadays even. If you really wanted, I guess? you could compile on Linux (distrowatch.com says Fedora yes, Ubuntu only 4.4.4) with GCC 4.5.1 (or whatever) -mtune=3Datom and use http://agner.org/optimize/#objconv to convert it to COFF and then link it with DJGPP, if you think the new optimizations might help (doubt it but who knows). Another solution (horrible, I admit) would be to use handcode some SSE bullcrap, but that's usually more pain than it's worth (and hey, I like assembly!). We just can't program new computers effectively like they are the old ones we're used to. What exact versions are you using? GCC 4.4.4? DJGPP 2.0[34]? FreeDOS kernel 203[6789]? CWSDPMI r[567]? It all might make a difference. Of course, posting code would explain more too, but again, I don't have any similar (netbook) hardware to test for you.