32 bit v's 64 bit kernel

[Simon Wiltshire]

hi, we have a 64 bit kernel running a 32 bit version of Progress (9.1d). can you tell me the difference and might i encounter any problems?

[Peter Godron]

Simon,
generaly 32bit written applications will run ok in a 64bit environment, but will not make full use of available resource.
Can not confirm for certain with Progress.
Are you experiencing any errors?

[James R. Ferguson · Accepted solution]

Hi Simon:

One thing to be aware of is that there are kernel tunables that specifically govern 32-bit processes regardless of the fact that the kernel inself is a 64-bit one.

Perhaps, the most notable ones are 'maxdsiz', 'maxdsiz_64bit', 'maxssiz', 'maxssiz_64bit', 'maxtsiz' and 'maxtsiz_64bit'. For more information, see:

http://docs.hp.com/en/TKP-90202/index.html

Regards!

...JRF...

[Jeff Schussele]

Hi Simon,

The difference between 32-bit & 64-bit environments is strictly addressability.
A 32-bit app, including an OS, can only address 4 GB of memory whereas 64-bit can address up in the Terabytes.
So as long as Progress, the OS & all other 32-bit apps can keep their memory mapped within that 4 GB address space you'll be alright.

Rgds,
Jeff

[Ted Buis]

There are no problems running a 32-bit binary on the 64-bit version of HP-UX. There might be something if the application is really doing something out of the ordinary in handling the memory quadrants, but that was very rare. There is a white paper on memory windows at www.docs.hp.com (just go there and search on memory windows). You have the same limitations in the application with the 64-bt OS as with the 32-bit OS. Memory Windows were developed to help 32-bit applications get more use of memory in the 64-bit OS.