Panel rendering performance with Stretchctrl

[DustyPorViva]

I've been recently messing around with DrawingPanels and I'm a bit curious.

If I render a 800x600 canvas Panel(one the size of the player's Graal window, for example), and in a timeout clear it repeatedly and draw an image, it lags. That's understandable, it's a fairly large canvas and a lot of canvas to constantly fill.

However, if I render a 320x240 canvas and do the same thing, the lag is decreased significantly... almost none at all for my shoddy computer. That's great! It makes sense too, it's much less canvas to render and fill.

However, why if I use a guistretchctrl to stretch the 320x240 canvas over the screen, it lags just as bad as the first scenerio? At first I thought maybe it was my graphics card not being able to render transparency well, but I remember that seteffect does the same thing, and even with the whole screen being filled black(no transparency at all), it still lags.

Is this a bug, an oversight or something or just the way it's going to work?