From: Karsten Scholtyssik Newsgroups: comp.parallel Subject: Re: parallel programming using a multiprocessor Pentium Date: 21 Jun 1999 20:52:45 GMT Organization: Aachen University of Technology / Rechnerbetrieb Informatik Approved: bigrigg@cs.cmu.edu Message-Id: <7km8mt$ndg$1@goldenapple.srv.cs.cmu.edu> Originator: bigrigg@ux6.sp.cs.cmu.edu Xref: ukc comp.parallel:15684 Rod Moten schrieb in im Newsbeitrag: 7jrv09$7rn$1@goldenapple.srv.cs.cmu.edu... > I'm in the market of buying a multiprocessor based on the IBM PC > platform. In particular, I want to buy machine with four Pentium II > processors. Has anyone any experience writing parallel applications on > such a system? You should be aware that most off-the-shelf PCs have a bad memory subsystem. So if you are going to write memory intensive applications it is possible that your applications don't scale well. I don't know if there are high-end PCs that use e.g. a crossbar to access the memory. > Does the Pentium have atomic instructions like Swap and > TestAndSet? Yes it has. You can even use a LOCK prefix to a lot of operations which turns the operation into an atomic one. The Pentium manual says: "The LOCK prefix is typically used with the BTS instruction to perform a read-modify-write operation on a memory location in shared memory environment" Karsten -- Articles to bigrigg+parallel@cs.cmu.edu (Admin: bigrigg@cs.cmu.edu) Archive: http://www.hensa.ac.uk/parallel/internet/usenet/comp.parallel