4 ms·

I run in i386 becaues it uses less memory (though I think I'll be switching)

by listic 12y ago

davidw 12y ago
Yeah, on hosting systems where memory costs money, 32 bit can be a significant savings. I wrote this a few years ago: http://journal.dedasys.com/2008/11/24/slicehost-vs-linode/ http://journal.dedasys.com/2008/11/24/slicehost-vs-linode/
- listic 12y ago
  Also, there are often cases where memory on your computer is either non-expandable or already maxed out. I maxed out my laptop with 8 GB and I don't feel like I have memory to waste with the usual office tasks, on Ubuntu. Being conservative and remembering that Ubuntu switched to "recommending" its 64-bit variant as default on its start page less than a year ago, naturally I chose 32-bit the last time I reinstalled the system. But, I'll choose 64-bit next time, because I see mainstream software support shifting to 64-bit for some applications, and because I read up Phoronix tests where 64-bit shows noticeable performance advantage.
dbaupp 12y ago
Linux offers the x32 ABI[1] for this reason: small 32-bit pointers but maintaining the advantages of x86-64 (more/bigger registers etc). [1]: http://en.wikipedia.org/wiki/X32_ABI http://en.wikipedia.org/wiki/X32_ABI
- deleted 12y ago
  [deleted]
- srean 12y ago
  Have you used it or know people who have ? I am very curious about the experience and the details. Are there distributions that ship with libraries compiled with X32_ABI ?
  - krakensden 12y ago
    Ubuntu?
  - ldng 12y ago
    Maybe some embedded systems distro have tried but as far as I know not any major distro. That would probably uncover quite a lot of bugs and require adaptations since lot of code assume Intel and compatible are either x86 or x86_64 and address memory accordingly. There are some people trying to port Archlinux to x32 but I really don't know the status. [edit] An one year old LWN article : http://lwn.net/Articles/548838/ http://lwn.net/Articles/548838/
  - dbaupp 12y ago
    I seem to have /libx32 and /usr/libx32 (and they're non-empty too) on my Debian unstable system.
pron 12y ago
Java uses 32-bit pointers in 64-bit mode by default. http://docs.oracle.com/javase/7/docs/technotes/guides/vm/performance-enhancements-7.html http://docs.oracle.com/javase/7/docs/technotes/guides/vm/per...
- xxs 12y ago
  While a nice feat (32bit on <32GB heaps) 64bit pointers allows for storing metadata (more than 3bits* ) in the pointer itself. Having the class id alongside the pointer can be quite profitable. Other than that the 32bit pointers are a clear win with small heaps. * If the hardware ignores the lower 3bits they can be utilized for various needs (e.g biased locking[0]) [0] http://www.azulsystems.com/blog/cliff/2010-01-09-biased-locking http://www.azulsystems.com/blog/cliff/2010-01-09-biased-lock...
  - emn13 12y ago
    Generally, the hardware doesn't ignore those bits, so you'll need to mask em, and that costs some performance. All in all, it's probably a win, but it's not entirely free either. It really depends on what you're going to stick in those extra bits. Java's assumption that you'll use those bits to address more memory is not a bad one; after all, for workloads between 4 and 32GB there's probably no optimization better than dramatically increasing memory density.

I run in i386 becaues it uses less memory (though I think I'll be switching)

by listic 12y ago

I run in i386 becaues it uses less memory (though I think I'll be switching)

Yeah, on hosting systems where memory costs money, 32 bit can be a significant savings. I wrote this a few years ago: http://journal.dedasys.com/2008/11/24/slicehost-vs-linode/ http://journal.dedasys.com/2008/11/24/slicehost-vs-linode/

listic 12y ago
Also, there are often cases where memory on your computer is either non-expandable or already maxed out. I maxed out my laptop with 8 GB and I don't feel like I have memory to waste with the usual office tasks, on Ubuntu. Being conservative and remembering that Ubuntu switched to "recommending" its 64-bit variant as default on its start page less than a year ago, naturally I chose 32-bit the last time I reinstalled the system. But, I'll choose 64-bit next time, because I see mainstream software support shifting to 64-bit for some applications, and because I read up Phoronix tests where 64-bit shows noticeable performance advantage.

dbaupp 12y ago

Linux offers the x32 ABI[1] for this reason: small 32-bit pointers but maintaining the advantages of x86-64 (more/bigger registers etc). [1]: http://en.wikipedia.org/wiki/X32_ABI http://en.wikipedia.org/wiki/X32_ABI

deleted 12y ago
[deleted]
srean 12y ago
Have you used it or know people who have ? I am very curious about the experience and the details. Are there distributions that ship with libraries compiled with X32_ABI ?
- krakensden 12y ago
  Ubuntu?
- ldng 12y ago
  Maybe some embedded systems distro have tried but as far as I know not any major distro. That would probably uncover quite a lot of bugs and require adaptations since lot of code assume Intel and compatible are either x86 or x86_64 and address memory accordingly. There are some people trying to port Archlinux to x32 but I really don't know the status. [edit] An one year old LWN article : http://lwn.net/Articles/548838/ http://lwn.net/Articles/548838/
- dbaupp 12y ago
  I seem to have /libx32 and /usr/libx32 (and they're non-empty too) on my Debian unstable system.

pron 12y ago

Java uses 32-bit pointers in 64-bit mode by default. http://docs.oracle.com/javase/7/docs/technotes/guides/vm/performance-enhancements-7.html http://docs.oracle.com/javase/7/docs/technotes/guides/vm/per...

xxs 12y ago
While a nice feat (32bit on <32GB heaps) 64bit pointers allows for storing metadata (more than 3bits* ) in the pointer itself. Having the class id alongside the pointer can be quite profitable. Other than that the 32bit pointers are a clear win with small heaps. * If the hardware ignores the lower 3bits they can be utilized for various needs (e.g biased locking[0]) [0] http://www.azulsystems.com/blog/cliff/2010-01-09-biased-locking http://www.azulsystems.com/blog/cliff/2010-01-09-biased-lock...
- emn13 12y ago
  Generally, the hardware doesn't ignore those bits, so you'll need to mask em, and that costs some performance. All in all, it's probably a win, but it's not entirely free either. It really depends on what you're going to stick in those extra bits. Java's assumption that you'll use those bits to address more memory is not a bad one; after all, for workloads between 4 and 32GB there's probably no optimization better than dramatically increasing memory density.