MFC executable is 100% slower on faster machine
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From: Peter Olcott on 22 Jan 2010 16:43 I recently upgraded my computer hardware from a 2.4 Ghz Celeron to a 2.66 Ghz Core i5 and an MFC application that I developed runs only half as fast on the faster machine. What could be causing this? Both machines have identical sata hard-drives, and the fast machine has much faster RAM 1333 ddr3 and 4.0 GB. The slower machine has 2.0 GB of 333 ddr RAM. Why is the slower machine twice as fast on the same executable?
From: Alexander Grigoriev on 22 Jan 2010 22:16 Is the application multithreaded? Is it floating-point intensive, memory-intensive, and what else? "Peter Olcott" <NoSpam(a)SeeScreen.com> wrote in message news:6PydnYAu9qOHgcfWnZ2dnUVZ_v2dnZ2d(a)giganews.com... >I recently upgraded my computer hardware from a 2.4 Ghz Celeron to a 2.66 >Ghz Core i5 and an MFC application that I developed runs only half as fast >on the faster machine. What could be causing this? > > Both machines have identical sata hard-drives, and the fast machine has > much faster RAM 1333 ddr3 and 4.0 GB. The slower machine has 2.0 GB of 333 > ddr RAM. Why is the slower machine twice as fast on the same executable? >
From: Peter Olcott on 22 Jan 2010 22:29 I is very memory intensive, thus much faster memory and much larger cache should make it faster and not slower. It is also single threaded and no floating point is used at all. I bought the Core i5 specifically because it has faster access to RAM. "Alexander Grigoriev" <alegr(a)earthlink.net> wrote in message news:%23BWgrp9mKHA.1548(a)TK2MSFTNGP02.phx.gbl... > Is the application multithreaded? Is it floating-point > intensive, memory-intensive, and what else? > > "Peter Olcott" <NoSpam(a)SeeScreen.com> wrote in message > news:6PydnYAu9qOHgcfWnZ2dnUVZ_v2dnZ2d(a)giganews.com... >>I recently upgraded my computer hardware from a 2.4 Ghz >>Celeron to a 2.66 Ghz Core i5 and an MFC application that >>I developed runs only half as fast on the faster machine. >>What could be causing this? >> >> Both machines have identical sata hard-drives, and the >> fast machine has much faster RAM 1333 ddr3 and 4.0 GB. >> The slower machine has 2.0 GB of 333 ddr RAM. Why is the >> slower machine twice as fast on the same executable? >> > >
From: Alexander Grigoriev on 23 Jan 2010 00:02 Do you see much disc activity when you run it? In your new computer, does the CPU fan spin OK? CPU not overheated? Note also that when processing large arrays, you want to avoid cache and TLB thrashing. Better to read the array sequentially than scatter the reads all over the place. "Peter Olcott" <NoSpam(a)SeeScreen.com> wrote in message news:tY6dnTjgpPqo8MfWnZ2dnUVZ_oWdnZ2d(a)giganews.com... >I is very memory intensive, thus much faster memory and much larger cache >should make it faster and not slower. It is also single threaded and no >floating point is used at all. I bought the Core i5 specifically because it >has faster access to RAM. > > "Alexander Grigoriev" <alegr(a)earthlink.net> wrote in message > news:%23BWgrp9mKHA.1548(a)TK2MSFTNGP02.phx.gbl... >> Is the application multithreaded? Is it floating-point intensive, >> memory-intensive, and what else? >> >> "Peter Olcott" <NoSpam(a)SeeScreen.com> wrote in message >> news:6PydnYAu9qOHgcfWnZ2dnUVZ_v2dnZ2d(a)giganews.com... >>>I recently upgraded my computer hardware from a 2.4 Ghz Celeron to a 2.66 >>>Ghz Core i5 and an MFC application that I developed runs only half as >>>fast on the faster machine. What could be causing this? >>> >>> Both machines have identical sata hard-drives, and the fast machine has >>> much faster RAM 1333 ddr3 and 4.0 GB. The slower machine has 2.0 GB of >>> 333 ddr RAM. Why is the slower machine twice as fast on the same >>> executable? >>> >> >> > >
From: Peter Olcott on 23 Jan 2010 00:19
"Alexander Grigoriev" <alegr(a)earthlink.net> wrote in message news:uwRS9k%23mKHA.2544(a)TK2MSFTNGP04.phx.gbl... > Do you see much disc activity when you run it? In your new > computer, does the CPU fan spin OK? CPU not overheated? > I did not notice any significant fan speed here. CPU is constant 100% on the single core machine, and constant 25% on the quad core. > Note also that when processing large arrays, you want to > avoid cache and TLB thrashing. Better to read the array > sequentially than scatter the reads all over the place. The aspect of the program in question creates 65 MB data to be written to disk. Brand new identical disk drives on both machines. > > "Peter Olcott" <NoSpam(a)SeeScreen.com> wrote in message > news:tY6dnTjgpPqo8MfWnZ2dnUVZ_oWdnZ2d(a)giganews.com... >>I is very memory intensive, thus much faster memory and >>much larger cache should make it faster and not slower. It >>is also single threaded and no floating point is used at >>all. I bought the Core i5 specifically because it has >>faster access to RAM. >> >> "Alexander Grigoriev" <alegr(a)earthlink.net> wrote in >> message news:%23BWgrp9mKHA.1548(a)TK2MSFTNGP02.phx.gbl... >>> Is the application multithreaded? Is it floating-point >>> intensive, memory-intensive, and what else? >>> >>> "Peter Olcott" <NoSpam(a)SeeScreen.com> wrote in message >>> news:6PydnYAu9qOHgcfWnZ2dnUVZ_v2dnZ2d(a)giganews.com... >>>>I recently upgraded my computer hardware from a 2.4 Ghz >>>>Celeron to a 2.66 Ghz Core i5 and an MFC application >>>>that I developed runs only half as fast on the faster >>>>machine. What could be causing this? >>>> >>>> Both machines have identical sata hard-drives, and the >>>> fast machine has much faster RAM 1333 ddr3 and 4.0 GB. >>>> The slower machine has 2.0 GB of 333 ddr RAM. Why is >>>> the slower machine twice as fast on the same >>>> executable? >>>> >>> >>> >> >> > > |