Re: [eigen] Eigen 3 is extremely slow |

[ Thread Index | Date Index | More lists.tuxfamily.org/eigen Archives ]

*To*: eigen@xxxxxxxxxxxxxxxxxxx*Subject*: Re: [eigen] Eigen 3 is extremely slow*From*: Benoit Jacob <jacob.benoit.1@xxxxxxxxx>*Date*: Mon, 14 Mar 2011 09:57:14 -0400*Dkim-signature*: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=nyFWx8tifmapoK/50HUH8H5wfcQmQ566IYmug2ykgho=; b=MakcSKCHGiea0FSuFhH5VjpVm8zcDvXos8lGJ2lxd8d8WyiifiupoFLIirS6pVEXxC 5KzoF6nUokO0GJj82kofIXGAkaR7z3GJ5LH/alwonJdbW/rFaND7vCLVuNqzi6kPTfWN zllrVDKdAA0oaPbrgDYnFIAPjF7ZGPt+3nmwI=*Domainkey-signature*: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=gtyM7MpQI+R73bvs30CatbUNcn8c+a7S52Ao2EK/ImGZNTGOJsYUy0PP4cgtPtGKXt sbrxWRUj3cPoShuZQ0UC1Zjmsg3UY9sYdi0V8iVdPRq+q19dDLdXoKf+mdJdtHCgeomb uSlKVGhM1zU1+IyVRyke36d08tJt6rQOfrqYw=

2011/3/14 Hari Sundar <hsundar@xxxxxxxxx>: > I do not have any NaN values and I have checked it for my sample dataset. > > I did some additional tests and it appears that it is not the matrix > multiplication itself that is slow, but it appears to be some really bad > case of cache usage. > > Once projected, I use the points to sample from an Array (512x512). If I do > not use Eigen for this array (instead using a std. C array), then my > performance is much better. > > I hope that is able to point you in the right direction. As Hauke said, the only useful thing would be a compilable test case. Benoit > > I was using an ArrayXXf (also tried MatrixXf) to store the array. > > best, > Hari > > On Mon, Mar 14, 2011 at 9:18 AM, Benoit Jacob <jacob.benoit.1@xxxxxxxxx> > wrote: >> >> 2011/3/14 Gael Guennebaud <gael.guennebaud@xxxxxxxxx>: >> > On Mon, Mar 14, 2011 at 12:48 AM, Hari Sundar <hsundar@xxxxxxxxx> wrote: >> >> For example a simple 4x4 * 4*1 multiplication takes around 0.5msec. >> > >> > hm, that's indeed extremely slow... which compiler? flags? >> > >> > for instance here a 4x4 * 4x1 product takes less than 4e-6msec, and >> > even in debug mode (-g2) with a very old gcc 3.4 it takes less than >> > 0.0008 msec... >> >> If his matrix has NaN values, that could explain another 500x factor. >> >> Benoit >> >> > >> > gael >> > >> > >> > >> >> > > > > -- > +1 (215) 501 7752 > https://www.rad.upenn.edu/sbia/hsundar/ >

**Follow-Ups**:**Re: [eigen] Eigen 3 is extremely slow***From:*Hari Sundar

**References**:**[eigen] Eigen 3 is extremely slow***From:*Hari Sundar

**Re: [eigen] Eigen 3 is extremely slow***From:*Gael Guennebaud

**Re: [eigen] Eigen 3 is extremely slow***From:*Benoit Jacob

**Re: [eigen] Eigen 3 is extremely slow***From:*Hari Sundar

**Messages sorted by:**[ date | thread ]- Prev by Date:
**Re: [eigen] Eigen 3 is extremely slow** - Next by Date:
**Re: [eigen] Eigen 3 is extremely slow** - Previous by thread:
**Re: [eigen] Eigen 3 is extremely slow** - Next by thread:
**Re: [eigen] Eigen 3 is extremely slow**

Mail converted by MHonArc 2.6.19+ | http://listengine.tuxfamily.org/ |