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Max 5 metro vs. qmetro FPS differences with 4.6

May 6, 2008 | 7:39 am

This is with Max 5.01 on a PC with XP.
After all sorts of weird behavior with a big video patch and overdrive, I did a little sanity check with metro and qmetro.

In 5.0 a metro of 33.333 settles out to roughly 30.0 fps.
In 4.6 a metro of 33.333 settles out to roughly 30.0 fps.
in 5.0 a qmetro of 33.333 settles out tot roughly 27.5 fps
In 4.6 a qmetro of 33.333 settles out to roughly 29.99 fps
This is with a metro or qmetro attached to a FPS object, with a toggle to start it… nothing else.

Moreso, I normally notice an increased FPS in my patch when I enable Overdrive… but in 5.0 my fps drops from 27.5 fps using a qmetro to like 17 fps. Obviously there is a lot of patch dependency here… but the general issue is previously overdrive sped up my patch.. now it slows it down a LOT.

I didn’t think 4.6 and 5.0 were supposed to be that different under the hood, but what I’m seeing is a bit frightening.

Why would qmetro vary that much from metro?


May 6, 2008 | 7:49 am

Have you looked into the refresh interval scheduler preference? Sounds like you might want to investigate it.

David Z.


May 6, 2008 | 6:46 pm

– Pasted Max Patch, click to expand. –

The fps in my example are with all the scheduler settings at defaults. The only really major difference in those value occurs when I change event/scheduler intervals, or turn overdrive off and on. So refresh settings aren’t changing things at this simple level.


May 12, 2008 | 7:09 pm

Is this expected behavior?
I can use a smaller value for qmetro and get a higher FPS, so I’m not "capping out".

Id like to know if other people get the same variation, or if something is wrong with my system.

metro 33.33 = 30 fps
qmetro 33.33 = 27.5 fps

And sure, these are arbitrary values, but it makes me feel like I’m using something approximating appropriate video framerates and shuts up gadflys that check out my patch over my shoulder.


May 12, 2008 | 7:49 pm

I agree based on your example there might be something wrong with qmetro in Max 5, although timing accuracy is not really a reason to use it. I’ll investigate further.

David Z.


May 12, 2008 | 8:33 pm

qmetro’s long-term accuracy (better) and short term variability (worse) will be restored to 4.6 levels in the next post-5.0.2 update.

David Z.


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