It is my understanding that ESRI does not have a x64 version of ArcMAP yet. You can load ArcMAP on a x64 machine but it loads in x86 mode. I experienced this issue with my FME by Safesoft. I had to load the x86 version of FME on my x64 machine in order to use all of the ESRI file formats.
We need ESRI to come out with true x64 product or Autodesk needs to create messenger DLL's that can address the issue. I assume ESRI will eventualy get us a true x64 desktop product.
I can connect to our SDE server from x86 or x64 machines, also.
I don't know if this will help. At this time I am running Map3D 2013, prior rev 2012, 11... I have been using the Arcsde connection and Oracle connection to fdo for awhile. We also have been using ArcMap10 in conjunction with Map3D. The SDE server is 64 bit, and Map3D is 64 bit, of coarse ArcMap is 34 bit, also using Windows 7 op system. Out of the box Map3D, I inserted pe.dll(ver10.0.0.6850), sde.dll(ver10.0.0.6850), sg.dll(ver10.0.0.6850) into Program files>Autodesk>AutoCAD Map 3D 2013>bin>FDO. Then verified the service in Program Files>System 32>driver>etc>services, there should be a row, esri_sde 5151/tcp #SDE, if not you need to insert one. In Map3D Data Connection by Provider window, add your Connection name, server name, instance name(esri_sde), Data Store(Default Datastore in drop down), version(SDE.DEFAULT in drop down) and click connect. Your schemas and datastores should come up. Check the one you want to bring into Map(note: its slow, I'm currently testing different methods and dlls to help speed up). Another tip is make sure all data stores on the sde server are registered or you won't see them. We have multiple GIS folks using these softwares simultaneously. I will post again if I get the running slow on the sde server fixed. Good luck.
To get the 64 bit versions of the dll I had to install the ArcSDE client service (which is a 64 bit application) on my machine and then copy the DLLs over to the bin/FDO directory. We have all the proper licensing for this since we run the SDE server and ArcMAP. This worked fine for 2012 but now that I have installed 2013 I am running in to the same problems of not being able to connect to the FDO. Has anybody else had this problem and is there something different between 2012 and 2013 that I should be aware of. (and yes I did copy the dll files to the new installation.)
I am using Map 3D 2013 64 bit and connecting to a SDE server. It works fine. Did you check if you have an entry in C:\Windows\system32\drivers\etc\services file, esri_sde 5151/tcp #ArcSDE ver -Oracle.
C: Program Files>Autodesk>AutoCAD Map 3D 2013>bin>FDO>providers.xml, verify if OSGeo.ArcSDE.(version?) is correct, if not update version using word pad or note pad to modify the xml. Hope this helps.
Ok, I got it to finally work. I was using SDEQLSERVER:<servername> which originally worked under 2012 but for some reason doesn't under 2013 so I went back to using 5151:<servername> and am now able to connect. The 5151 changes based on which SDE I am connecting to which in our case is 5151 through 5155. Hopefully my pain and suffering will help someone else.
Thanks for the input.