[Bf-committers] Blender on Windows - some thoughts about XP and 32bit

[Thomas Dinges]

Hi everyone,
I want to share my opinion about some things regarding Blender on Windows.

Please note: This is just my own opinion and no decision of any kind has 
been made here, so please don't panic. I'd like to get the opinion from 
the other active Blender developers here.

1) Windows XP
======================
Windows XP is 13 years old and even Microsoft itself drops support for 
it once and for all in April 2014.
Sometimes we have bugs that only happen on XP, we have some (little) 
special code in libraries such as OIIO for example to support XP....

I think it's time to fade out the support for it. If a vendor (in this 
Microsoft) doesn't even support its product any longer, why should a 
third party do it? Also on a side note, XP has a lot of security holes 
by now and they won't be patched. Microsoft itself expresses a clear 
warning to users: 
http://news.techworld.com/security/3476295/microsoft-to-windows-xp-users-your-operating-system-is-a-major-security-risk/

It should be easy to keep the binaries working, but on a support level 
(Support in bug tracker, system requirements on blender.org) I suggest 
to mark XP as "not officially supported any longer".

2) 32 bit
======================
Dropping 32 bit for the Windows platform is nothing that should happen 
soon, I guess some people still use Windows Vista and 7 with 32bit OS.

Nevertheless, if we take a look at our minimal system requirements: 
http://www.blender.org/download/requirements/ , it mentions a Dual Core 
CPU with SSE2 support. Afaik all those CPUs support 64bit instructions 
so no new hardware would be required, just a OS update.

Also, there is always Linux, if people want to keep using older hardware 
but cannot afford an update to Windows 7/8.

3) Problems and chances
======================
So, why do I bring up this topic? This has several reasons.

Developer team
---------------------------
Windows developer team is quite small already, compared to Linux/OS X 
platform. I think we have some devs who develop on it but actual 
platform maintenance (libraries, release builds) is done by 2-3 people 
max. And I don't think any of us is still using a XP/32bit setup.

Personally I don't use 32bit systems for several years already, and I 
would be very happy if someone could take over support for that. It just 
takes a lot of time to compile libs (like recently new OIIO/OSL) for 32 
bit as well, fix (compile) errors, build 32 bit Blender, run some tests 
and make sure it works all fine.

MSVC 2008
---------------------------
Using a 5 year old compiler is a bad thing. Not only can we get a much 
better performance for (Cycles) Rendering for example, by using a recent 
version (like MSVC 2012), we could also get rid of some special code in 
our libraries and patches which we added just to make it compile on this 
ancient compiler...

MSVC 2012 is 20% faster in Cycles rendering afaik, so we don't talk 
about some tiny numbers here.
So, why didn't we update yet? Lack of Windows developers and time. 
Especially if we have to build/update *all* libs for both x64/32 and 
make sure it runs smooth everywhere, this is just a boring task no one 
really wants to do.

Jürgen did a great job with his work on vc2012 libs, but I think he is 
busy lately and some things need to be finished here still before we 
could switch to this for official releases.

Other applications
---------------------------
Other 3D applications already dropped support for Windows XP and/or 
32bit: http://temp.dingto.org/SysRequirements.pdf

This is of course no real reason, but a pretty clear indication.

4) Possible plan
======================
Windows XP:
Blender 2.70: Last version with official support for Windows XP, after 
the release we remove it from blender.org (system requirements info 
text) and fade out support in the bug tracker.

Blender 2.71 and above: Binaries will probably still run fine on XP, but 
it might break at some point.

32bit:
Blender 2.70: Add a notice on blender.org, that we highly recommend 
using a 64bit operating system for best performance and best support.

And again, I'd like to hand over the support for Windows 32 bit to 
someone else, preferably someone who actually is *on* this platform and 
can test issues as well.


Sorry for the long mail and I hope you don't misinterpret this. I am 
very well aware of people living in poor countries who cannot update 
easily, but at the same time we also have to look forward and stop 
supporting ancient technology.

Best regards,
Thomas