Revit 2009 64 bit

[Doug]

Is the REvit 64 bit backwards compatible with Revit 32 bit?

[Andre Carvalho]

Yes. Files generated on Revit 2009 64 bits can be opened on Revit 2009 32 bits and vice-versa. I wouldn't even call it a backward compatibility. The systems are basically the same. Just the way they address memory is dfferent...

Andre Carvalho

[vanderloo5]

I just read something a day or 2 ago about possibly not being able to open models created in 64 bit, in a 32 bit install due to large file sizes. It was in the readme documentation regarding known issues with 64 bit Revit.

[patricks]

It's not that Revit 64-bit creates huge files, it's just that it has the capability to open and run huge files with more than 4 GB RAM, files that a 32-bit installation could not handle.

So if the file size is not so massive, then sure you can open a file in either 32-bit or 64-bit Revit.