May 30 Edit: This technique is essentially "obsolete" since the DGromacs core has been "fixed".
Disclaimer: This is an "advanced method," targeted to "competitive folders".
The DGromacs (double-precision Gromacs) are not using 100% cpu. It varies, but at worst, they use only about 50% cpu. At best, they use maybe 85%. When you see that the Idle Process has accumulated 26 bloody HOURS of cpu time, as it has on my desktop machine, and 64 hours on my Intel "blade", both of which fold 24/7, you know it's time to do something
What I have done on the three PC's I have easy access to, is to add an ADDITIONAL FAH directory
Remember to change the Machine ID on the extra instance by running the client with -config or -configonly. Machine ID is under "Advanced Options".
On my HyperThreaded machines, this means a THIRD directory. On the non-HT machine, a second directory. I do not run this extra instance as a service, but just from a shortcut on the desktop. I add the -oneunit flag along with -local -advmethods, etc., so that when the WU ends, it does not automatically pick up another one. This is so that in case the "permanent" instances happen to pick up a regular Gromacs, or God forbid, a Tinker, I won't run the "extra" instance beyond the completion of the current WU. This wouldn't be horrible, since my machines are plenty fast enough to return WUs before the deadlines even with multiple instances of FAH running, but I also feel it's important to return work as quickly as possible, and so long as FAH is using 100% cpu, there is no "points advantage" in running more than one or two (in the case of an HT cpu) instances of FAH.
It's when FAH is NOT using 100% cpu that I run the "extra" client, and even then, only after checking the Performance tab in the Task Manager to verify that a significant amount of cpu is going to the Idle Process.
How much difference does this make?
On my non-HT machine, LogStats said I was getting 386 PPW with the single DGromacs running. With a second DGromacs, 770. Virtually a 100% increase
On one of my HT machines, two instances were producing 909 PPW, which ain't shaby, but the cpu was not being used anywhere near 100%, so I started a third instance. With 3, LogStats says 1024, a 12% increase
- This technique can result in your "performance fraction" dropping below .95, which could mean you don't get some of the largest most complex work units, like the 160 pointers. If it would cause your performance fraction to drop below .8, I do not recommend it at all.
- This can sort of backfire. My second HT machine picked up a Tinker for the 3rd instance.
- This only makes sense on machines that are convenient to get to. This is a "manual" technique, so it requires a "hands-on" approach to folding
Answers to anticipated questions:
- How do I know I am working on a DGromacs?
The DGromacs core is FahCore_79.exe, which you can see in the Task Manager in the 'Processes' tab.
Better yet, install Electron Microscope III. It shows the DGromacs cores as a dark blue color, so you can see at a glance which core each of your clients is running.
- How do I create a copy of FAH?
- Right-click-and-drag an existing FAH folder and select 'Copy Here' from the option menu which appears when you release the right mouse button.
- Rename the folder to whatever you want.
- Descend into the copy and delete the
- work folder
- both log files
- Right-click FAH4Console.exe and choose Create Shortcut
- Right-click the shortcut, choose 'Properties' and add -oneunit and -configonly (or -config) in the 'Target:" box.
- Drag the shortcut to your desktop for easy access
- Double-click the shortcut to configure FAH.
- Change the Machine ID to one not being used by another client on that PC.
- Re-edit the shortcut to remove the -configonly flag
- Double-click the shortcut to start the extra instance of FAH.