Low/inconsistent frame rate on HP 1070US G7 laptop

[David O'Neil]

When I initially start Stellarium, the frame rate shown is about 50. After a couple seconds it drops to about 4.6, and Stellarium becomes very 'jumpy.' If I continually move the mouse around, feeding Stellarium mouse movements, the framerate remains about 50. Moving the mouse, then not moving the mouse corresponds to smooth, soon followed by jumpy behavior. Mouse movements will again make a higher framerate.

This is a dual core computer with two additional 'false' cores. I don't know if that has anything to do with the problem but I did check by using the Task Manager to limit Stellarium to just one core and the same problem existed. Also, setting the task priority to 'high' and above didn't change the behavior either.

Looking around, this may be a computer that HP has removed OpenGL from, but I can't tell for certain. Running Stellarium without OpenGL gives the same behavior, so it doesn't seem to be the issue. (And if OpenGL was the issue, I don't believe Stellarium would give the higher initial frame rates to begin with.)

I have the most up to date video drivers installed. This machine has the Intel graphics built into the motherboard, as far as I know.

I have also tested this on another older HP laptop (Win7-32bit) with only a dual core (no false ones), and the issue doesn't exist there.

Running Stellarium 0.12.4, Windows 7, 64 bit. The same issue existed with earlier versions on this computer, but I don't remember which one I last used - I believe it was 0.12.1.

I don't know if this has anything to do with it, but I hibernated my system last night and now Stellarium (which was a running task) is showing a framerate of 5.43e-05 FPS, or other similar numbers. Pressing 'L' a few times to speed up the time rate (and moving the mouse around) proves that it is really about 50 FPS.

[David O'Neil (cppege-david)]

Of course, after all of this I find that I had long ago set minimum_fps to 5 and maximum_fps to 10, in an effort to reduce processor usage when Stellarium is at a standstill. Changing min to 100 and max to 1000 gets rid of the issue, so Stellarium is, except for the bad FPS display, working as it is somewhat designed. Except the initial 40 to 50 FPS when it is set to limit to 10 is confusing. And the fact that Stellarium is throttling to the minimum number, not the maximum number.

[gzotti (georg-zotti)]

Going to minimum_fps if you don't move the mouse is intentional - it saves power.
If your Stellarium survives hibernation, be happy!
G.

[David O'Neil (cppege-david)]

>> If your Stellarium survives hibernation, be happy!

Hmmm. Sounds like an opportunity for an improvement! :) Unfortunately, no time...

And the maximum_fps must also be broken, from your reply, and another bug report I read.

If I did have time, one item I'd really like to see in Stellarium is if the user sets the timerate to 0, and possibly 'twinkle' to off, but not necessarily, I'd make it so the loop simply redrew the last frame and slept for 20 ms. Can't be that hard to accomplish, and I get really tired of seeing a processor going full-out for that situation. But as I said, I don't have time right now...

Best wishes,
David

[Alexander Wolf (alexwolf)]

A fix has been committed as revision 6676 of the trunk branch in Stellarium's Bazaar repository at Launchpad: http://bazaar.launchpad.net/~stellarium/stellarium/trunk/revision/6676