x264 epic FPS Drop....lmm(losing my mind)

[shaqsalazar]

Hi, i dont understand whats going on.Im encoding a movie at CRF @ 14, when it starts encodeing the FPS is above 60, but after like 2 mins to drops to like 11 FPS....WHYYYY is that? is it a encode proeblem(x264) or is it my cpu(no likely).


Also im not riunning anything demanding in the background while the encoder is encoding


Plz help

[swing4thefence]

I'm using both Handbrake and XviD4PSP and in both cases I also start out strong, well over 60 fps but that declines as it progresses.
I left my laptop on last night and set power management to none. I set up a batch in Handbrake. I had 4 mkv files to encode and when I went to bed at 1:00 AM I was at 75fps. I figured all 4 movies would complete in a couple of hours and I'd be done. When I came back in the morning at 7:00, only one had completed and my FPS was down to 7.

I waited 2 more hours for the second to complete and then ended it.
Then I put one movie in Xvid4PSP and ran it to see if it would work better than handbrake. Again I started around 70Fps but now as I'm 87% complete I have declined all the way to 6.5 fps.
My task manager shows XviD$PSP at around 30% and ax264.exe at about 40%.

Any ideas?

[jagabo]

Some frames compresses faster than others. For example, totally black frames compress much more quickly than highly detailed moving shots. Movies often start with a fade from black, static logos, and static titles. So it's not unusual for the frame rate to drop once the actual movie starts. Your drop from 75 fps to 7 fps does seem excessive though.

How does CPU usage compare when starting and later when slowed? What about memory usage?

[poisondeathray]

And what is the CPU speed and temps both starting and when slowed? Overheating and CPU throttling might be another possiblilty, especially on a laptop. Not all power management settings are necessarily accessible through the OS (You might have to go into the BIOS)

Also, were you using 1pass CRF encoding ?

The OP was using CRF encoding (I'm assuming 1pass) , but if you're using multipass encoding , the 1st pass is usually much faster (as an analysis pass) unless you specifically specify --slow-firstpass settings . So with multipass encoding your observations might be "normal" depending on the settings used

[swing4thefence]

I just booted to my BIOS and I didn't see any power management options in there. I'll check my power profile to make sure it's not throttling the CPU. *UPDATE I don't see anything that throttles my CPU in the power management.

[Selur]

check your cpu temperatures during encoding in example using CoreTemp (modern cpus will throttle by itself, no bios setting)

[jagabo]

Just looked at your profile:

AMD FX-8150 8 Core OC - 4.7 ghz

Overheating, CPU throttling.

[poisondeathray]

That's a desktop for the OP, the 2nd post is a laptop