Audacity Forum

steve wrote:What I guess is happening, is that your high performance dedicated graphics card is also doing its own caching. (Running two Hi Def monitors requires a huge amount of data). Unfortunately it seems that your graphics card is not quite "smart enough", and can be tricked (by rapid scrolling) to hold old cache data longer than it should, and so sometimes display low resolution (pixelated) waveform data rather than the most recent waveform data.

I think it would be kind of extraordinary if this problem shows up only in Audacity, while all other applications work absolutely flawlessly - many of which are much more demanding for the graphics card.

Until I spot a similar problem in another application, which I have not (so far), I have to suspect that it must be a problem on Audacity's side. Triggered only under certain conditions...

steve wrote:A driver update for your graphics card (if available) may solve the problem

As mentioned above, I already use the latest WHQL drivers.

steve wrote:or making less demands on the card (for example, running only one monitor, or using lower definition, or a lower refresh rate).

For LCD screens you don't have much alternative to running on the "native" resolution (anything else will be interpolated to the "native" resolution by the screen anyway). And you certainly wouldn't want that

Same about the refresh rate. Pretty much all LCD screens run at 60 Hz. Some of those fancy new "4K" screens can do only 30 Hz (because of a bandwidth limitation of the DVI connection) and the result is that the mouse cursor doesn't move smoothly anymore.

Gunnar wrote:I think it would be kind of extraordinary if this problem shows up only in Audacity, while all other applications work absolutely flawlessly - many of which are much more demanding for the graphics card.

Yes but you are describing a very specific problem involving cached data.

Gunnar wrote:I have to suspect that it must be a problem on Audacity's side.

Except that your other machines with the same version of Audacity do not produce the problem, my machine does not produce the problem, none of the Audacity developer's machines produce the problem, none of the thousands of forum users have reported the problem, and none of the millions of other Audacity users worldwide have reported the problem, which would lead me to think that it is something to do with your machine.

I have once come across a similar issue (about three years ago), and that turned out to be a problem with the video drivers.