I have sent in the same request via the official support page, but hoping for a quick solution, I thought I might just as well post it here for discussion, too:
I have been using Directory Opus for years now on Windows XP x86 without issues.
I recently switched to using XP x64 and encountered the following problem:
Running Prime95 (V25.6 x64) in the background (at lowest possible priority 1 out of 10) significantly slows down my file copy operations in Directory Opus. I lose about 10-20 MB/s on average.
Experimentally raising priority of Prime95 to 2 slows file copy down to a crawl completely.
It seems that some important part of the file copy operation in DOpus on XP x64 is running at idle priority, while it should be running at normal (or at least higher than idle) priority.
Can you confirm this and/or give me some kind of a solution to the problem? As it stands now I am not able to run Prime95 anymore.
Since web support didn't know I thought I might clarify.
All you need to know about Prime95 is it's running at idle priority taking all the cpu it can get. It shouldn't interfere with any normal tasks on the computer, since everything normally runs at higher than idle priority. Works fine on x86.
There's no difference in the way the 32-bit and 64-bit versions of Opus copy files, at least if we are talking about simple file copies between two standard directories. (If you're copying into or out of a Zip file then there are some slight differences.) So if you only see the problem on 64-bit Windows then I doubt it is down to Opus.
What happens when copying files using other programs? Do you see the same thing? Does it make a difference whether the program doing the copying is 32-bit or 64-bit?
Assuming Prime95 is a 32-bit app, perhaps there is a issue with the way XP x64's task scheduler schedules 32-bit and 64-bit apps? Or perhaps Prime95 is accessing the disk or using other resources which will slow other things down regardless of priorities?
Have you tried using Process Explorer to look at the Opus and Prime95 threads? Maybe not all of Prime95's threads are at low priority, even though the overall process is?
I have already been told by support that all DOpus threads run with higher than idle priority.
Concerning the question whether it only happens in DOpus, I am still doing some testing. It's not that easy to do with Windows Explorer which lacks a "time left" and "mb/s" display. Still experimenting.
You might well be right, it's not DOpus fault.
Prime95 exists in 64 and 32 bit flavors btw.
I was already looking for a tool that can show me the priority of each running thread individually. I will try Process Explorer out, thank you for the hint.