collatz: getting windows_intelx86 instead of windows_x86_64 cuda app

I posted the following on collatz message boards, reposting here in case one of you have an idea.

I have 2 boinc clients running on the same machine. One client ignores gtx 690 gpu 0 and the other ignores gpu 1, to solve an issues with getting collatz to run on both engines.

One of the clients insist on running solo_collatz_4.07_windows_intelx86__cuda50.exe and the other runs solo_collatz_4.07_windows_x86_64__cuda50.exe. I assume the x86_64 is what should be running. Neither has app_info.xml, both have app_config.xml (which are identical).

Both clients start up with log message "Starting BOINC client version 7.2.33 for windows_x86_64".

I have reset, detached/attached, detached, removed any boinc programdata file that referenced collatz in its name, reattached. Always the same result the one client runs the 32 bit app. I cannot figure out why. Ideas?

The server has the flag "<prefer_primary_platform>1</prefer_primary_platform>" which is supposed to mean that it sends x64 to x64 capable hosts. Why does it need this? Some 64 bit apps run slower than the 32 bit apps and the project admins are too stupid to remove the 64 bit app. So, DA decided once again to save the project admins from themselves and come up with a complicated algorithm for the BOINC client that is supposed to learn which apps to use. That means the BOINC client is supposed to download some of each and figure out which runs faster. I don't believe that it works. So, your only option is to set the no_alt_platform option in the cc_config.xml file. The problem with that is that if a project only has 32-bit apps, your 64-bit host will not download any WUs since it will only use x64 versions.

That all having been said, even though nVidia and AMD have separate 32 and 64 bit drivers, behind the scenes, the GPU code is all 32-bit so it really doesn't matter whether the CPU portion of the app is 64-bit since it spends 99.9% of the time running on the GPU which is running 32-bit code.

In other words, don't worry about it, just make sure the .config files are setup for both versions. I had only the x64 version config files setup, I noticed the exe switch when the GPU utilization dropped and times went up. Since my original email, all of my clients have switched to 32-bit version on their own.