I was recently reading Tracy Kidder’s excellent book Soul of a New Machine.
The author pointed out what a big deal the transition to 32-Bit computing was.
However, in the last 20 years, I don’t really remember a big fuss being made of most computers going to 64-bit as a de facto standard. Why is this?
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any time you use ram more than 4 GB that is part of the 64 bit change
or having a file bigger than 4 GB, or a disk partition that is bigger than 32 GB
but yeah, because they quickly became the norm, not a whole lot of noise was made about them after the transition.
any time you use ram more than 4 GB that is part of the 64 bit change
64bit cpu not needed for that. See PAE.
The actual limiting factor (in x86 specifically) is that a single process view on memory is 32bit thus 4GB. This is specific to the design of the CPU; it’s very well possible to get around that with techniques such as overlays or segmentation, as 16bit x86 demonstrated very well.
Then there’s processors like the 68000, which offered a 32bit ISA with direct 32bit addressing (although only 24 exposed in the physical bus, until 68010 had versions with more address lines, and 68020 with full 32bit), despite 16bit ALU.
Similarly, SERV implements a compliant RISC-V in a bit-serial manner.
Of course, having 64bit GPRs specifically is very convenient past 4GB.
or having a file bigger than 4 GB
Large offsets are possible in 32bit too. In e.g. Debian Linux, it is common in all architectures other than x86.
or a disk partition that is bigger than 32 GB
32bit block addressing to 512 byte blocks yields 2TB.
And again, software can handle 64bit values in 32bit (even 16 and 8) architectures no problem. It’s just slower and more cumbersome, but the compiler will abstract this away. For disk I/O addressing, it is a non-issue, as latency of the disk will make the cost of these calculations irrelevant.
It was noticeable for us because Exchange 2008 was the first M$FT product that only ran 64. That was our first 64-bit box
Of all applications - email needed 64 bits!
Kind of. Exchange is a memory hog.
Exchange takes all the memory you got.
Well we are still kind of transitioning to 64-bit. Chip makers/designers are still having to include instruction sets for 16/32-bit which does limit in some respects on how big the transition really is.
Removal of those would break a lot of software, especially removal of 32bit support. Bye, bye thousands (if not millions) of Windows 95/98/XP games & programs!
One of the big features of Windows is its backwards compatibility.
Gee really? Here’s me thinking 32-bit instruction sets were cosmetic. Thank you for ignoring the part where I said we’re still in a transition phase.
Also, with a bit of tinkering, you can run 16-bit applications. It’s just recommend to use virtualisation applications because Microsoft doesn’t ensure quality updates for 16 bit applications.
Point is that seldom used instructions are microcoded anyway, so they take zero space on the CPU.
I honestly don’t know when you are talking about. CPUs aren’t storage devices.
Originally, A 64bit OS was popular in the enterprise space. Businesses were running Windows NT using 64bit. I think the first version of Windows meant for consumers that got the 64bit upgrade was a version of Windows XP Pro X64, but it was uncommon. 64bit didn’t go mainstream until Windows 7. Before that, most PC hardware upgrades didn’t have 64 bit device drivers available. Even now, 64bit isn’t a requirement most of the time. You can get 64bit versions of a lot of applications, but a lot of applications still come as 32bit only.
Windows XP 64bit was a… oddball operating system, it wasn’t just Windows XP but 64bit, there were notable technical differences between 32bit and 64bit Windows XP that can hinder software compatibility (Plus driver support wasn’t that particularly good for the 64bit version either).
Windows Vista was when the 64bit version was essentially the 32bit version but 64bit. ie: they’re no longer significantly different.
XP 64 was a Server 2003 64bit edition for workstations. They had the same kernel as well. Oddball, but it did work well if you could find your drivers. I went straight to 7 64 after that.
Right,
- Windows XP Professional 64bit is Windows 2003 kernel & something like the XP UI. This is why you can run in to software compatibility issues.
- Windows XP 64bit (non-professional) was only ever available for Intel Itanium and Itanium 2 CPU’s.