We've been on 64 bit for about 3-4 years and on quad core for about 2 years. Our current Archicad 12 uses all of our cores and is much faster than AC11. When we got our 64 bit quad core computer (2 years ago), it tested 40% faster than the than fastest Mac, which was also 64 bit quad core. Our computers were much faster than any 32 bit windows computer. However, with AC12, I don't know if that is still the case and the 64 bit part was partially an ego thing - because it is nice to have the fastest! Having more bits also accellerates generation of graphic images with some software. I think that Lightworks makes use of it.

When we got our computers, Archicad would only support upto 4MB RAM - I don't know if that is still the case. 64 bit OS's will support much more, but it isn't much good if the software doesn't use it.

XP Pro 64 and Vista 64, does not support VR. Whilst we can generate the images, we can't play VR walk-throughs. XP32 and Vista 32 does support this. It is an Apple thing, apparently, because they haven't written the drivers for 64 bit Microsoft OS's. It is the only feature that we have missed. Is this worth the (possible) extra speed - only you can tell.

KeesW wrote:
Archicad would only support upto 4MB RAM - I don't know if that is still the case.

http://www.archicadwiki.com/TechNotes/How%20to%20Check%20Virtual%20Memory%20Usage

that Wiki article is a little bit ambiguous regarding the future though .. it kind of implies that a 64bit OS (OS10.5+ or Vista/Windows 7) still has the 4GB application limit. This is true only if the application itself is still 32bit ... it has nothing to do with the OS. It is up to application developers to write 64bit applications ... e.g Cinema4D was only written for 64bit on the Mac as of R11, but has been available as a 64bit on Windows since a late R9 version i believe.

And this is where we run into a big problem ... Graphisoft has to update AC to be 64bit for us to be rid of the 4GB RAM limitation. I think you will see some pretty significant performance gains in AC when this happens, but i fear given GS track record on supporting hardware developments we will not be seeing true 64bit support before AC15.

this is a pretty good article on the whole 32/64bit RAM addressing issue:

The Road to Snow Leopard

[Edit]: Changed the link above to an updated article on Apple Insider

owen wrote:
And this is where we run into a big problem ... Graphisoft has to update AC to be 64bit for us to be rid of the 4GB RAM limitation. I think you will see some pretty significant performance gains in AC when this happens, but i fear given GS track record on supporting hardware developments we will not be seeing true 64bit support before AC15.

I think you can be confident that GS will support 64-bit processors as soon as it's practically possible, programming-wise. It's the same issue with full multi'-core support. And they have other acute issues too, like a new 3D engine.

I'd say their biggest problem isn't really implementing these technologies in new versions. The hardest obstacle to overcome is probably to maintain support for "legacy" hardware and O/Ss, and keeping it all bug-free as well.

Remember, Vista 64 isn't very wide-spread yet, so they will have to support 32-bit WindowsXP, which is 8 years or something old, for some additional time to come.

owen wrote:
it has nothing to do with the OS. It is up to application developers to write 64bit applications ... e.g Cinema4D was only written for 64bit on the Mac as of R11, but has been available as a 64bit on Windows since a late R9 version i believe.

There is one significant hurdle to overcome regarding Mac 64-bit development (at least for older apps). When Apple moved to OS X, they provide a compatibility layer for older applications to make the transition from OS 9 to OS X simpler. Developers were strongly encouraged to develop new apps for OS X based on Cocoa, a very comprehension application framework. There were some clear advantages to doing this, but Cocoa is based on Objective-C - a big hurdle for existing apps and a bit of a learning curve for developers.

The alternative to Cocoa, designed to migrate apps from the old Mac API, is Carbon. Apple vacillated between assuring developers Carbon would remain an equal partner with Cocoa and implying/warning that Carbon might not be around forever. As the OS moved to 64-bit, both Carbon and Cocoa API's were revised accordingly. Then, out of the blue, Apple suddenly announced there would be no 64-bit Carbon (even though it was apparently finished), and all apps would have to embrace Cocoa in order to be full 64-bit.

This has left developers of older apps - including old stalwarts like Adobe - with quite a significant hurdle to leap (and a culture change too - Objective-C isn't exactly alien, but it's different enough). This isn't so bad if you make a clear distinction between pure application code and API-dependent code, but I suspect many older apps have a lot of skeletons in their code-closet. This may mean a lot of work migrating ArchiCAD to 64-bit on the Mac OS - it depends very much on the code structure and organisation. Just don't be surprised if it takes longer than you'd like.

Thanks Ralph .. i was generally aware of the Cocoa/Carbon issue as it related to both C4D and Adobe. Apple should have been a bit clearer, but you would also think developers would see where the future lies and start their migration sooner rather than later. CS5 will most probably be 64bit and that is not in the too distant future ... end of the year maybe, so not long after Snow Leopard probably ships.

Ralph wrote:
Just don't be surprised if it takes longer than you'd like.

What is AC15 not pessimistic enough for you? I guess i can make some assumptions from this as to what Graphisoft has NOT migrated to yet : (