Based on my understanding of 64 bit hardware, the advantage of 64 bit comes from the wider bus, which is the highway between the system memory and the cpu. An analogy might be the difference between a four lane highway, as opposed to a two lane highway, or a two niche water pipe as opposed to a 1 niche water pipe. In the case of the four lane highway, you can move much more traffic than in the two lane highway. Likewise, a two niche pipe will move much more water than a one niche pipe over the same period of time.
In working with very large numbers on 64 bib hardware in 32 bit emulation mode, two 32 bit reads by the cpu is needed to get the large number, whereas in a 64 bit mode, very large numbers can be read and manipulated with a single read. Also, a 64 bit bus allow for tremendously larger numbers than a 32 bit bus, thus a 64 bit bus can address a much larger amount of memory, reducing page swaps that are needed in 32 bit mode. 32 bit software running on 64 bit hardware requires the 64 bit flow of data be broken down into two 32 bit pieces to emulate a 32 bit bus. Therefore you will only see substantive increases in speed on the 64 bit hardware, if running something like a 64 bit scientific app that is using very large numbers, for example. Likewise, increases can be achieved by adding memory above the 4 gig 32 bit memory limitation to run memory natively in 64 bit mode. Again, the applications must be compile using a 64 bit programming language to take advantage of the 64 bit native memory model. Also, you may seen big increases in speed on web, database, and application servers that are carrying heavy loads, if the applications have been ported to a 64 bit language like C or C++ or example, like the 64 bit version of MSSQL. Otherwise, the 64 bit hardware will not show much difference in speed from the 32 bit hardware. It is my understanding that many applications packaged in both 64 bit Linux and Windows are not currently compiled to 64 bit, so you may really be running 32 bit packages in the 64 bit OS. Eventually all the OS(s), and apps will be written to 64 bit, but things still seem to be in transition now. It will be up to the application developers to port their apps to 64 bit. So far as compatibility is concerned, the 64 bit hardware of today should run all your 32 application, including VFP, without any problems. 64 bit is the future and I would hope that VFP will someday be ported to 64 bit with the 2 gig file size limitation increased. Here is a link: http://zone.ni.com/devzone/cda/tut/p/id/5709 or http://tinyurl.com/3dxhoc Jeff Johnson wrote: > I searched the archives and found some information especially a post by > Jim Eddings that VFP ran fine on 64bit OS's. I was informed today that > one of my customers is moving data to a 64bit data file server and > terminal services applications may soon follow. > > I understand that VFP will run in this environment but someone asked if > there is anything special to getting your applications to run in > compatibility mode? Or is this detected by the OS and it happens > automatically? Are there any other concerns I should have? > > TIA for your comments. > > _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/[EMAIL PROTECTED] ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
