Is this CPU throtling already? Or not?

[N-drju]

I am puzzled. I have just run a test render of my current project and was quite terrified to see that CPU was stumbling at 1% efficiency. The first thought that came to my mind - thermal throttling. I should probably mention that hard drive was working at 100% (lots of objects).

However, when I launched the default scene and rendered that, the CPU usage was at 100%. Now, I am rendering a previous increment of my project and CPU is, again, at full speed. What is going on? My computer has not been powered down between any of these operations.

Could it be that very high object count is causing this behavior and slowing things down like that?  RAM is not a problem - I get a constant 10GB reading (16 total).

[Matt]

If your hard drive is working at 100% then whatever program is causing the hard drive to do that will be waiting for it, so its use of the CPU will be low. If it happens to be Terragen that's waiting for that data then the CPU usage will be very low until it gets the data to work on.

Terragen may be using more than 16 Gb of data even if Windows reports less. The way Windows task manager reports memory usage can be a bit confusing, to say the least.

[WAS]

Terragen may be using more than 16 Gb of data even if Windows reports less. The way Windows task manager reports memory usage can be a bit confusing, to say the least.

That would be detrimentally dangerous to system stability let alone OS. If windows think it's using 16gb and allows other programs to allocate X memory that isn't available. You can exception at very least, and at very worse failed DIMMs or corrupt applications/temp.

Maybe you're referring to cached assets a program is using, which are on virtual memory?

[N-drju]

If your hard drive is working at 100% then whatever program is causing the hard drive to do that will be waiting for it, so its use of the CPU will be low.

Then it looks like it's not throtling thanks goodness. Even less because my computer is just warm, not hot to the touch like that time when I completely ignored cleaning and grease replacement.

But I have to wonder what kind of data TG could have been working on that could not get retrieved for one hour when the test render was running. I don't use any other programs when running TG. Except for the browser and Reader maybe.

That would be detrimentally dangerous to system stability let alone OS. If windows think it's using 16gb and allows other programs to allocate X memory that isn't available. You can exception at very least, and at very worse failed DIMMs or corrupt applications/temp.

I can see a very good reason for the manufacturers to do this.

[Matt]

Terragen may be using more than 16 Gb of data even if Windows reports less. The way Windows task manager reports memory usage can be a bit confusing, to say the least.

That would be detrimentally dangerous to system stability let alone OS. If windows think it's using 16gb and allows other programs to allocate X memory that isn't available. You can exception at very least, and at very worse failed DIMMs or corrupt applications/temp.

Maybe you're referring to cached assets a program is using, which are on virtual memory?

Virtual memory of course. Applications allocate from virtual memory and the OS decides what is mapped to physical and what is paged out to disk.

[Matt]

I'm not saying Windows doesn't know how much has been allocated, because of course it does. It has to manage which VM pages get mapped to the physical RAM, which pages get swapped out to disk, and whatever else it does. I just mean that recent versions of Task Manager don't seem to report the total amount that the app has allocated, at least as far as I can understand it. It may say 10Gb but the total system allocation may be more, and if Windows is swapping some of that to and from the drive you'll get reduced CPU usage.

[WAS]

Huh I haven't taken note. I know in past versions, like when I was using massive virtual memory to save from pop crashes, it was accounting for virtual memory, showing way more than physical memory.

Though it's hard to tell what TG is really using as far as physical assets once loaded and populated to begin with.