Change FAHCore_23 (process) priority in Windows

[ETA_2025]

Running FAHCore_23 in Windows, and I'm struggling to get the process priority to be Normal or Above Normal, rather than Idle or Background.

Changing it is easy (Sysinternals Process Explorer), but it keeps resetting. How can I make the change permanent?

[muziqaz]

This is windows issue, not fahcore
And why do you need to change priorities? Whatever fahcores are set to by windows scheduler is fine, no need to mess with it

[ETA_2025]

This is windows issue, not fahcore
And why do you need to change priorities? Whatever fahcores are set to by windows scheduler is fine, no need to mess with it

Because running it on the sixth or seventh priority, of a seven priority scale, unnecessarily slows it down.

[calxalot]

I believe folks use Process Lasso

[muziqaz]

This is windows issue, not fahcore
And why do you need to change priorities? Whatever fahcores are set to by windows scheduler is fine, no need to mess with it

Because running it on the sixth or seventh priority, of a seven priority scale, unnecessarily slows it down.

What computer are you running it on to feel the slow down from normal process priority?
What else are you running on that PC?
If you have dedicated folding box, try not to run processes which are competing with fah. If you are folding on a side on a pc which is doing other more important things, then leave some threads free for those processes. Fahcores don't usually like process priorities changed.

[ETA_2025]

I believe folks use Process Lasso

Thanks calxalot. Problem solved.

This is windows issue, not fahcore
And why do you need to change priorities? Whatever fahcores are set to by windows scheduler is fine, no need to mess with it

Because running it on the sixth or seventh priority, of a seven priority scale, unnecessarily slows it down.

What computer are you running it on to feel the slow down from normal process priority?

Windows 11, Intel i7-7700 (not folding), 32 Gb of RAM, GeForce RTX 4070 (folding).

What else are you running on that PC?

GPU folding on my main computer.

Fahcores don't usually like process priorities changed.

That's not my experience on v8.4.9.

If you are folding on a side on a pc which is doing other more important things, then leave some threads free for those processes.

7 of 8 threads are free.

FAHCore_23.exe's default process priority is idle 4 (the lowest) and normally uses only 2-3.5% (of 12.5%) of the CPU's capacity.

A process priority of Normal or even Above Normal uses most of the 12.5% of CPU capacity available to it. Isn't this better (and okay)?

[muziqaz]

Have you seen any improvement in PPD output (excluding margin of error)?
Fahcore23 is GPU core and it does compute on a GPU. Fahcore23 CPU usage is just driver overhead and not compute.
No need to obsess about things which OS scheduler already does better and on the fly

[ETA_2025]

Have you seen any improvement in PPD output (excluding margin of error)?

Yes. Up 1.184 million points per day, though I'm unsure exactly how much of that is due to the higher CPU priority. I have stopped folding for long periods due to a heatwave here, and was interrupting the last work unit.

Fahcore23 is GPU core and it does compute on a GPU. Fahcore23 CPU usage is just driver overhead and not compute.
No need to obsess about things which OS scheduler already does better and on the fly

Well if the core is using around 12% with a higher priority, doesn't that mean it wants to use that much, at that time? So, if it's only using 2-3.5% then surely it's being unnecessarily delayed, and couldn't that slow down the GPU, as it waits for the CPU to finish what it's doing?

[muziqaz]

Process priority on the idle core will not add more usage.
CPU time is different going from project to project. One project asks 5% of the CPU, other project requests 12%. This is just kernel times from OS/driver.
Compute itself is done by GPU and that does not care of CPU is running on higher priority or not. Unless, your system has other apps which are demanding compute time from the CPU, that way robbing some resources from the core which is taking care of driver overhead. If that is the case then, yes, higher priority would help, because fahcore would have a priority over other apps to use that core.
Remember, that different projects give you different PPD, and upload times influence PPD, as well as your desktop usage influences PPD by quite a bit

[ETA_2025]

I believe folks use Process Lasso

It turns out that you don't need to do that. You can just put an entry in the registry.

Specifically, at:

Code: Select all

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\fahcore_23.exe\PerfOptions

create:

Code: Select all

CpuPriorityClass

which is a Hexadecimal DWORD (32-bit) Value.

Possible values are:

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Priority        Value
--------        -----
Realtime          4
High              3
Above Normal      6
Normal            2
Below Normal      5
Idle              1

Background is not relevant, because it is just Idle with low I/O and Memory priority, and I'm not sure what it's value is.

Actual Display:

Code: Select all

Name                                                                               Type                Data
----                                                                               ----                ----
CpuPriorityClass                                                                   REG_DWORD           0x00000004 (4)

I believe that the default CPU priority of Idle accounts for some or all the average PPD discrepancy when folding with GPU on Windows, compared to Linux.

[ETA_2025]

Process priority on the idle core will not add more usage ...

I know all this. But, normally System Idle Process is at more than 80%, so I don't think giving fahcore all the CPU time it wants, will significantly slow down my computer.

[muziqaz]

Process priority on the idle core will not add more usage ...

I know all this. But, normally System Idle Process is at more than 80%, so I don't think giving fahcore all the CPU time it wants, will significantly slow down my computer.

But there is no need for that. You are doing things just in the sake of doing things. It's same as buying a system with 128GB of RAM and then stripping your OS to bare minimum to see it idle at 127GB available memory. Modern system do not need that kind of tinkering anymore. There is no performance benefit, since CPUs are overly powerful enough to mask all of it. If you are doing something else on the CPU while folding, then fair enough, distribute your system resources manually if you think OS scheduler does poor job, but we are talking about FAH being the only compute resource doing stuff on the GPU, while CPU is using 1 or half of the core (out of 8+ or whatever modern systems have) to deal with the driver overhead, which is not even compute and does not contribute to how fast GPU is doing its job. While you are trying to do all this tinkering (plus now registry editing) you are at a risk of bricking FAHcores and WUs downloaded in the name of something utterly unnecessary.
You have to understand, regardless of what Windows perceives to be high or low priority processes, FAH on unused system is not being challenged by anything OS related. FAH tasks take highest priority unless there is another high load process competing with it, which in this case it isn't.

[ETA_2025]

Process priority on the idle core will not add more usage ...

I know all this. But, normally System Idle Process is at more than 80%, so I don't think giving fahcore all the CPU time it wants, will significantly slow down my computer.

FAH tasks take highest priority unless there is another high load process competing with it, which in this case it isn't.

In my experience it doesn't. It is assigned the lowest processor priority, of Backgound, and can only use the CPU after everything else has. Which is why the CPU use on Backgound is normally 2-3.5%, while on Realtime it's 11.8-12.7%?

And, currently fahcore_23's process priority is Background, but it is running at Realtime because that what's in the Registry. What changed it to Background? I assume Windows thinks it's a background task (which it is), and assigns it Background processor priority.

Anyway muziqaz, you're debating theory, while I'm talking about experience. No offence, but I'll trust my experience.