On Mon, 30 Apr 2007, Wayne Dernoncourt wrote:
Intel and AMD both have multi-core CPU's out now. I'm wondering how difficult it is to modify existing code to use this ability? We have some compute bound code that seems to have multiple threads, the vendor says that in their testing (from years ago) that multiple processors didn't help much (for their code). Now that multiple core CPU's and multiple CPU systems are becoming more common, are there applications which can use multiple cores effectively?
Sure. The easiest case is when you are running more than one CPU-intensive application. Multiple threads within a single application will require more communication between them, and so will receive less of a speed-up (exactly how much depends on the application). Applications which are more I/O-intensive will also not benefit as much, as multiple CPUs don't speed up network or disk access. If you open up your OS's performance monitor (Task manager for Windows, "System Monitor" for Linux, etc.) and you see the CPU usage at or near 100%, then you definitely have one or more CPU- intensive applications. Some applications, though might receive less of a speed-up due to OS synchronization issues (I once worked on an app that did so many tiny memory allocations that running it on a multiple CPU machine actually slowed it down). -- Vicky Staubly http://www.steeds.com/vicky/ [EMAIL PROTECTED] ************************************************************************ * ==> QUICK LIST-COMMAND REFERENCE - Put the following commands in <== * ==> the body of an email & send 'em to: [EMAIL PROTECTED] <== * Join the list: SUBSCRIBE COMPUTERGUYS-L Your Name * Too much mail? Try Daily Digests command: SET COMPUTERGUYS-L DIGEST * Tired of the List? Unsubscribe command: SIGNOFF COMPUTERGUYS-L * New address? From OLD address send: CHANGE COMPUTERGUYS-L YourNewAddress * Need more help? Send mail to: [EMAIL PROTECTED] ************************************************************************ * List archive at www.mail-archive.com/[email protected]/ * RSS at www.mail-archive.com/[email protected]/maillist.xml * Messages bearing the header "X-No-Archive: yes" will not be archived ************************************************************************
