Is there any point in making a 32bit OS anymore?

[arkain]

The subject line pretty much sums up my question. I'm trying to design a new OS based on a few concepts I came up with several years ago. Since 64-bit x86 CPU's are pretty much ubiquitous, is there any good reason to design a new OS from scratch for a 32-bit x86 CPU?

[Combuster]

1) It's easier </opinion>
2) x86_64 isn't ubiquitous enough for everybody to have one as a spare test system. (you don't generally want to use your dev machine as experimentatal hardware)
3) Not everybody is rich/spoilt enough to upgrade his hardware every two years. Expect a lot of P4's or Athlon XPs in production use, and older atoms in laptops. You can save big money by sticking to slightly dated hardware.

[Coty]

I also think that 32bit is easier (also my opinion)

I think continuing 32bit deving is a good idea, I know I would not want to test my OS on a brand new machine, I'd be to afraid that I would flunk it.

There are still allot of people with 32bit PCs, were I live I only know 3 people with 64bit computers, and I know a nice amount. I can also go over to walmart and buy 32bit PCs new, and cheaper than a 64bit, the way the economy is here every dime counts.

Many netbooks have 32bit processers, I can't think of a 64bit netbook at the moment.

You can pick up junky computers for a few bucks at yard sales and such. These make great test beds and allot cheaper, if you screw it up, you don't lose much.

[54616E6E6572]

My opinion, as usual, differs from most everybody elses. Also lets not forget that Microsoft has already released Windows Server 2008 R2 as 64-bit only, with rumors that Windows 8 will follow suit, meaning that all future machines will be 64-bit only.

64-bit machines are getting cheaper and cheaper. My Quad-Core AMD with 8GB of DDR3, 2TB hard drive, 1200W power supply and an ATI Radeon HD 5670 graphics card only cost me around $400, and that was bought a couple months after the parts came out, furthormore 90% of the machines I have seen built by the major computer companies in the past 5 years have been x86-64 machines.

I also find 64-bit development easier. More registers, SIMD instruction support is standard, larger address space, better security features, etc...

Finally there are tons of virtual machines with 64-bit support so there is no -real- need to worry about crashing your computer, and lets face it, if your starting an OS, and your going to work on it by yourself, in your spare time. Then by the time you get even close to having something usable, 64-bit computers will more than likely be standard. Hell, my OS with all it's fancy features took me 2-3 months to write and all it does is display a pretty boot screen with vector fonts and gradients, and thats mostly because I wrote it specifically for my AMD64 machines. It takes months and years to write an OS, even if you know what your doing, especially if you want it to be portable to other machines.

[Artlav]

In my opinion, don't forget about it.
It's not that hard to design most of the programs and core things to compile with 32 and 64 bits alike, leaving only the basic kernels to write.
Of course, that assumes you're making the entire project in a portable way.

Also, 32 bit systems might be fading from x86, but there are other devices that won't let it go.

[bewing]

It's a toss-up. It depends on your intended audience and the reason why you are building an OS. If you are building it for your own use only, then (obviously) aim it at the hardware that you have, period. You can port it to 32b later if you really have to. If you want everyone to be able to buy/use it, or if this is an educational exercise in portability, then starting with 32b is probably wise. Also, aiming at 32b technology forces you to be a bit more memory efficient. But adding goals like portability and memory efficiency to your OS means it will take that much longer to create.

[VolTeK]

If you go 64 bit only, and are wanting people to use your os, think about people who probably dont want to upgrade. Surprisingly yes, some people still use computers that are only 32 bit only compatible. Its better for people to get an os to use, to just get the job done, and not have to upgrade or go through hell to come up with money for their next computer, but instead want to stay with the old one they had.

Its simple, No extra money payed. Just installation, and run. And your set until the next release.


64bit only is a bad idea. What happens to the people who dont have computers that cant run it? (a probable percentage of the population) Wont be buying or running it. When you release an os, you cant expect everyone who buys it to buy another computer.

What about compatibility? Seriously how many people are using 64 bit, and who cares what they are using, most people just use the computer to get on the internet. They dont care about it being 64 or 32 bit, and some dont even know what it is. As long as its compatable, performs nicely on the computer they have, and its simple to use and isnt resource hungry. well.. all in all

Simplicity matters. Be as compatible, fast, stable, and easy as it can be.

[tharkun]

ARM is still 16/32 bits.

Most embedded processors are 16 bit only, or have 16 bit databuses to make the board cheaper which has the side effect 16 bit instruction decoding faster than 32 bit decoding.

[Owen]

ARM is still 16/32 bits.

Where does the "16/" in that come from? ARM is a completely 32-bit instruction set (unless you're referring to instruction length, but by that token x86 would be a 8/16/24/.../120 bit instruction set...)

[TylerH]

Not about ARM's bitness:

IMO, a kernel should be designed so that the core can be shared between all archs. Just make a pmode OS that uses flat segmentation, then add PAE+PSE support and you're almost done porting it to long mode. That's assuming you're not coding it in asm.

[gravaera]

IMHO, MS shouldn't be dictating what's acceptable for my kernel.

[Candy]

Where does the "16/" in that come from? ARM is a completely 32-bit instruction set (unless you're referring to instruction length, but by that token x86 would be a 8/16/24/.../120 bit instruction set...)

Thumb/Thumb2 I guess.

[roboman]

Is there a point in writing any software any more? The point... Do you want to take on Microsoft? Be the next Linux? Or is the question really, are there still going to be 32 bit systems. There are still 32 bit systems being made and sold new. Will that stop? I think that depends on what Intel / amd decides to do as far as cost and what they are willing to make. That and what Microsoft does. There is the other side to look at, Droid is mostly open source software sitting on top of linux, why not a free Droid clone. I only see 3 points in writing any software, 1) to make money, 2) to provide something that's fun or useful to others, 3) because you want to. There are still people programming for the z80, 6502, amiga and even people building cpu's out of 74** logic chips. The only point in doing any thing is what you get out of it. The sub question, is the 32 bit pc still going to be around in a couple years.... That's a question about money, markets and what several companies decide. That and what they can sell the public. Can they sell a 64bit cpu for the price they sell the 32bit ones for the net books or are they going to care about that market in a few years? Is the Arm / google / linux thing going to kill the Intel / Amd / Microsoft / Linux / Apple thing?

[rdos]

My opinion, as usual, differs from most everybody elses. Also lets not forget that Microsoft has already released Windows Server 2008 R2 as 64-bit only, with rumors that Windows 8 will follow suit, meaning that all future machines will be 64-bit only.

Does this matter for OS developpers? Even if a server runs a 64-bit OS, it doesn't mean it can't run a 32-bit OS as well.

64-bit machines are getting cheaper and cheaper. My Quad-Core AMD with 8GB of DDR3, 2TB hard drive, 1200W power supply and an ATI Radeon HD 5670 graphics card only cost me around $400, and that was bought a couple months after the parts came out, furthormore 90% of the machines I have seen built by the major computer companies in the past 5 years have been x86-64 machines.

Yes, but AFAIK, 64-bit processors still have the 32-bit legacy mode, and thus can still run 32-bit OSes.

I suspect that 64-bit processors will support legacy mode a long time yet, mostly so that 64-bit OSes can still run 32-bit programs. Those will need to be supported in the Windows environment for a long time yet.

[rdos]

I think there is a point, especially for a project that already have lots of non-64 bit assembly code. There is also a point for embedded systems, that will basically never need 64-bit addressing.