> On 7 May 2016, at 3:28am, Keith Medcalf <kmedcalf at dessus.com> wrote:
> > I presume you mean that running 32-bit application on a 64-bit OS is > slower than the same application run on a 32-bit OS. > Hold on. The original poster was talking about using a 32-bit DLL, not a > 32-bit application. I don't know what Windows' limitations are. > n 64-bit windows can you run a 64-bit application which uses a 32-bit DLL? Not in-process. The in-process cpu mode must be the same. You cannot load a 64-bit DLL into a 32-bit process nor a 32-bit DLL into a 64-bit process. > Or does the fact that the application uses a 32-bit DLL mean that it must be > 32-bit itself ? Yes. There is no in-process thunking. That technology was an IBM technology and remained IBM technology after the breakup of the IBM Microsoft JAD in which OS/2 3.0 became also known as Windows Net Technology. > Either way, what I found is that 32-bit apps run at expected speed if > they're just doing stuff internally. The delays come when you meet a > 32/64 interface, for example if a 32-bit application is constantly > fetching data from a 64-bit source supplied by the 64-bit OS. Never experienced this myself. Except of course for COM and DCOM crap, (and dotNOT), where it is to be expected. I have never seen or experienced this with proper applications however. > Simon.
