1

Most of the software you can download over the internet for free, provide both 32 bit and 64 bit versions. But since most of them do not require to address so much memory, what is the advantage to this double distribution, since the moment 32 bit application runs perfectly on 64 bit systems? Do I miss something? thank you

ABCplus
  • 3,981
  • 3
  • 27
  • 43
  • The word "perfect" just does not apply. – Hans Passant Mar 13 '14 at 14:59
  • Yes, I know that they run under x86 emulation (WOW64 under Windows). I wrote "perfect" because I've not seen any significant difference in application speed or response time. – ABCplus Mar 13 '14 at 15:04
  • You'll find a good example [here](http://stackoverflow.com/a/21938676/17034). Lots and lots of questions about the awkwardness of the file system and registry redirectors here as well. – Hans Passant Mar 13 '14 at 15:10
  • Ok, but I don't think that the 32bit and 64bit application distribution is just because of that specific case (or other similar). – ABCplus Mar 13 '14 at 15:39
  • Try some code that uses math or register extensively and you'll see the difference. Some benchmark [here](http://www.phoronix.com/scan.php?page=article&item=ubuntu_32_pae&num=1) – phuclv Mar 14 '14 at 08:04
  • Another example is [x32 abi](https://sites.google.com/site/x32abi/). They can use the extended 64-bit registers but also limit the pointers to 32-bit, so the performance are quite good compared to x86 or x86_64. You can look at the benchmark at the end – phuclv Mar 14 '14 at 08:08

1 Answers1

0

Even though there might be no technical reason to have a 64-bit version right now 32-bit apps support will slowly decline and so it's time to start porting. If they just refuse to have a 64-bit version until it is absolutely required they will have to port it very fast (not only change the code but also test that everything works which is far from trivial and far from fast). So it's kind of a way to have a slow transition - they already ported the code and now they are kind of testing it so that when 32-bit code can no longer run they are fully prepared.

Community
  • 1
  • 1
sharptooth
  • 167,383
  • 100
  • 513
  • 979