Hi,

Simple question, I want to limit the FPS to around 60 so the CPU can sometimes go into halt and not toast itself. Which option is better for this?

Fullscreen vertical sync : ON
or
Limit frame rate: 60
?

Thanks.

I don't think VSync will get your fps to around 60.

VSync does get it to exactly 59.99, because my monitor is 60Hz (LCD).

I'd say there is no difference if you limit it to 60 or let vsync limit it to 60. As far as I know vsync delays your frames a bit (it waints until he next refresh), whithout this option the frames get immediately send to the monitor.

You can try to go to window mode (shift + f4) and open the taskmanager (ctrl + alt + entf) to see how much cpu power lfs eats.

Then again, we're obviously not talking about GPU-cooling, so the difference is, as far as I know, absolutely minimal. I'm not really a techy guy, but I do know that LFS is more reliant on the power of the CPU than the GPU in many cases.

Limiting the FPS won't change the amount of physics-stuff the CPU has to work with.

I might be wrong though, but I guess that what you get for not posting in the right forum

You are wrong, because the core physics calculations (always at 100 Hz) only takes about 5 % of the CPU power with some more % for multiplayer prediction, ect. The rest are calculations related to the graphics, so limiting the FPS will definatiely cool the CPU.

Ok, you better ignore my post then Sorry!

I'll agree though that this is more of a hardware topic than an LFS topic. Thread moved.

If your goal is to limit CPU usage, I'd say go with the frame rate limiter. When vsync is enabled most drivers will do a busy wait at each buffer swap until the frame is synced with the screen. Basically the CPU wil ask the graphics card "are you done yet?, are you done yet?, are you done yet?, are you done yet?, etc." until the card eventually syncs the frame and tells it "yes I'm done, quit nagging". This pegs the CPU at 100% usage.

Now, if you use the built in frame rate limiter, LFS will calculate approximately how much time it has to spare after rendering each frame, and will put the CPU to sleep until it is time to start the next frame. This frees up CPU cycles, but it may result in tearing (two different frames being displayed at the same time) since the frame rate is not actually synced to the screen's refresh rate.

Obviously, there are bound to be programs that stress the processor so you should really fix the cooling problem (if there is one)..

VSYNC is perfect for LCD screens, you get nice screen buildup with no tearing and a constant smooth framerate, as long as your pc can keep up..

Quote from GP4Flo :

You are wrong, because the core physics calculations (always at 100 Hz) only takes about 5 % of the CPU power with some more % for multiplayer prediction, ect. The rest are calculations related to the graphics, so limiting the FPS will definatiely cool the CPU.

where did you get those numbers ?

What are you guys on about? You can't do this its simply impossible. No matter what your cpu will still be used 100%., unless you have 2 cores then 1 core will be at 100% Limiting your fps will not cool down your cpu or allow "cool'n'quiet" to take effect.

By limiting your fps and turning vsync on you're only hurting yourself because the graphics card has to wait before it draws the next frame and in effect slowing it down.

Quote from Davo :

What are you guys on about? You can't do this its simply impossible. No matter what your cpu will still be used 100%.

Try the frame rate limiter in LFS, and then check the CPU usage. It works. Trust me.

And vsync doesn't hurt anyone. Your screen can't show any more frames than its refresh rate anyway, so if the FPS is higher than your refresh rate you're just skipping frames without even seeing them. As long as your computer can handle the (small) performance hit by using vsync, it will often result in smoother framerate in addition to eliminating tearing.

Click Start/run and enter "perfmon". This tool enables you to monitor CPU load. Personally I run LFS at 100 fps limit (monitor and LFS physics rate) and vsynch on.

Hey you're right. This is the first time I've experienced something like this, every other game has always used 100%. My cpu usage went down to 10% when I limited the fps to 30 but the game bacame very choppy. Somewhere around 60 would be the sweet spot. Vsync had no effect at all, I play with it off and don't notice any tearing. The fps thing is intersting though, I would've though it was more about gpu. This will come in handy when recording stuff with fraps to lower lfs cpu usage so fraps can record properly.

Under any form of load the CPU will remain at full clocks/voltages.

My C2D + LFS = 10-20%, limiting FPS will do sod all.

Thast more than enough to keep it at full clocks + voltages.

The CPU won't overheat unless you have cooling problems, and if you have you must sort them ASAP.

CR.