14 ms·

neverthelss the instruction set and especially encoding of the newer instructions is a nightmare. I wonder what ARM has to say about 64-bit computing, though

by RomP 16y ago

leoc 16y ago
> I wonder what ARM has to say about 64-bit computing, though Bad news on that one, at least for the first generation of nVidia chips based on the Cortex-A15. Segmented address spaces? They're baa-aack!
- rbanffy 16y ago
  64-bit is a big deal on x86 because with it came a couple extra registers and a better architecture overall. On modern machines, 64 bits usually only means more addresses, because they have plenty registers already. I remember that back when the 64-bit UNIX was introduced in, IIRC, SGI machines. Nobody made a big deal of it. SGIs were already very impressive and nobody cared that much for the extra bits in registers.
  - pmjordan 16y ago
    Back then, RAM was vastly more expensive than it is now, and processor speeds weren't great for processing gigabytes of data. Nowadays, the bigger address space is a big deal. Some of this is the OS (Windows is the biggest offender with its <2GB available user space addresses).
    - rbanffy 16y ago
      Even with Eclipse running and all of the memory allocated, less than 4 GB are currently being used for program workspace. The rest is being used by buffers. It's one of the cases when a PAE-like memory model would suffice. I cannot remember when was the last time a single program wanted more than 4GB (I can, actually, it was Firefox and I left it running with a page full of Flash thingies for the weekend - by Monday, it was unresponsive and I had to xkill it). I can agree we need 64-bit addresses for servers (and we have been needing them for quite some time now) but not for desktops and certainly not for my own computers.
      - pmjordan 16y ago
        Commercial PC game developers constantly run into the ~1.7GB address space available to user apps. You can forget memory-mapping any asset files. Windows can be booted with support for 3GB/process (same as the default on most Linux distros) but that's useless for mass market stuff. Even just running a 64-bit OS gives 32-bit user processes 4GB address space to play with.

neverthelss the instruction set and especially encoding of the newer instructions is a nightmare. I wonder what ARM has to say about 64-bit computing, though

by RomP 16y ago

neverthelss the instruction set and especially encoding of the newer instructions is a nightmare. I wonder what ARM has to say about 64-bit computing, though

leoc 16y ago

> I wonder what ARM has to say about 64-bit computing, though Bad news on that one, at least for the first generation of nVidia chips based on the Cortex-A15. Segmented address spaces? They're baa-aack!

rbanffy 16y ago
64-bit is a big deal on x86 because with it came a couple extra registers and a better architecture overall. On modern machines, 64 bits usually only means more addresses, because they have plenty registers already. I remember that back when the 64-bit UNIX was introduced in, IIRC, SGI machines. Nobody made a big deal of it. SGIs were already very impressive and nobody cared that much for the extra bits in registers.
- pmjordan 16y ago
  Back then, RAM was vastly more expensive than it is now, and processor speeds weren't great for processing gigabytes of data. Nowadays, the bigger address space is a big deal. Some of this is the OS (Windows is the biggest offender with its <2GB available user space addresses).
  - rbanffy 16y ago
    Even with Eclipse running and all of the memory allocated, less than 4 GB are currently being used for program workspace. The rest is being used by buffers. It's one of the cases when a PAE-like memory model would suffice. I cannot remember when was the last time a single program wanted more than 4GB (I can, actually, it was Firefox and I left it running with a page full of Flash thingies for the weekend - by Monday, it was unresponsive and I had to xkill it). I can agree we need 64-bit addresses for servers (and we have been needing them for quite some time now) but not for desktops and certainly not for my own computers.
    - pmjordan 16y ago
      Commercial PC game developers constantly run into the ~1.7GB address space available to user apps. You can forget memory-mapping any asset files. Windows can be booted with support for 3GB/process (same as the default on most Linux distros) but that's useless for mass market stuff. Even just running a 64-bit OS gives 32-bit user processes 4GB address space to play with.