On Aug 10, 2016, at 6:03 AM, Keith Medcalf <kmedc...@dessus.com> wrote: > >> Even on a 64-bit processor, there’s usually no reason to run 64-bit >> Windows unless you have more than 4 GB of RAM, a threshold we didn’t pass >> very long ago. > > Yes, please remember to keep the "addressable memory limits" linkage to > "processor bitted-ness" is a Microsoft Only phenomenon. You do NOT need > 64-bit processors or 64-bit Operating systems to be able to address more than > 4 GB of physical RAM. In fact that there are 32-bit versions of Windows (NT > 3.5, 4.0, 2000, XP, 2003 etc) which have been compiled without this > artificially imposed limitation. You pay more for "properly written and > compiled" software however because, well, it is easy to do stupid things and > impose stupid limits for no reason and you need higher wattage (therefore > more expensive people) if you want software that is not bounded by a crapload > of inane if not brain-dead) design decisions.
You must be talking about PAE, which is an unmitigated hack, in the dirtiest sense of that word: https://en.wikipedia.org/wiki/Physical_Address_Extension As you hint, some OSes allow individual apps to allocate extra RAM via PAE — UnixWare was one such — but due to the way PAE works, it can never be more than 8 GiB per process at a given time. The OS *could* page in and out 4 GiB segments to give a single application the run of the whole 64 GiB maximum space PAE allows, but I don’t know of any OS that does this. Linux in particular doesn’t let individual applications use PAE to access more than 3 GiB of VM space, with the standard 3/1 user/kernel split. Instead, if you have more than 4 GiB of RAM in the machine and are running a PAE kernel, it will let you have multiple programs *collectively* using more than 4 GiB of VM space. That’s not going the help the OP. Quoting Wikipedia, “…regular application software continues to use instructions with 32-bit addresses and (in a flat memory model) is limited to 4 gigabytes of virtual address space…no single regular application can access [all 64 GiB] simultaneously.” I believe the situation is essentially the same on PAE-enabled versions of Windows as on Linux. It is also the case that most machines that shipped with 32-bit Intel processors either didn’t have enough slots to allow > 4 GiB of RAM or didn’t have BIOS/EFI/chipset support for that much RAM if you did have the slots for it. And why should they have done? It just adds cost with a low chance that the user can make use of it, so that capability only showed up in high-dollar machines. PAE is also not restricted to non-Windows OSes. Microsoft simply chose not to support it on the non-Server versions of Windows, but that is essentially a market segmentation issue, not a technical one. PAE’s time is long past. 64-bit is the proper solution today. > It is also quite profitable to claim that your prior incompetencies were to > blame on "something else" and if everyone would just spend a boatload of > money and replace all the defective crap we sold them with a new boatload of > defective crap So…the software development industry is at fault for not building all their apps for 64-bit from the start, going back to the 1950s? Just think, you could be booting your Broadwell i7 into UNIX V1 today instead of this bloated Linux stuff! What a great thing that would be! >> Or maybe you’d like to look to a less legacy-bound company? Say, Google, >> who ships Chrome still built as 32-bit, originally for compatibility with >> 32-bit NSAPI plugins. Since they dropped that, I can only guess why >> they’re still building 32-bit binaries, and that guess is that with the >> tab-per-process isolation, no single tab needs more than 4 GB of VM space. > > Or they are using defective compilers (primary supplier in that field is > Microsoft) that cannot switch memory models without re-writing the code. Chrome runs just fine as a 64-bit executable. It just wasn’t the default version until recently. If you’ve been using it for a while, you will still be on the 32-bit version, as I am here. You have to do a full reinstall to switch to the 64-bit version, which is now the default for new users on 64-bit systems. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
