Re: Where's the Speed?
- To: mathgroup at smc.vnet.net
- Subject: [mg19783] Re: Where's the Speed?
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Fri, 17 Sep 1999 01:36:40 -0400
- Organization: Universitaet Leipzig
- References: <7rnklm$emb@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Kevin, I assume a unfortunate implementation. The speed gain is visible and between a factor of 5 to 20. Send me the source and I will take a look on it. You can still have my 1D and 2D Schr"odinger solver in MathLink with open boundaries. It should give you the result with a delay of 4-5 seconds even on a 100 MHz 486. Even the 2d version with 256 x 256 mesh points need only 30 seconds on a modern PC. Hope that helps Jens "Kevin J. McCann" wrote: > > I have read and heard a lot of hype about Mathematica 4.0 > > "featuring a > New Generation of > Fast Numerics" > > e.g. on www.wri.com . > > However, in the real world it is hard to find anything to get excited about. > I have had several disappointing results from 4.0, here are the latest: > > On a P450/NT I ran a very simple Crank-Nicholson integration of a > one-dimensional quantum free-particle wave-packet with x-dimensioned to 1001 > points and time to 401 points - no error checks or adaptive stepsize, just > plug-and-chug. Runtime under 4.0 was 501 seconds, 3.0 was 480 seconds, but > who's quibbling; however, in FORTRAN this ran in 8 seconds. I don't even > consider this to be "fast numerics", but 501 seconds sure isn't. I would > like to know where all this speed is so I can use some of it, or am I > missing something? > SNIP SNIP SNAPP