To highlight what I mean I've attached two images.
As the title suggests, the apparent quality of the model seen in the viewport is better (specifically, less jagged lines) when we are rotating the model or at least while holding down the middle mouse button and just slightly moving it, not even necessarily rotating it all around. This 'increased quality' stays until you release the mouse button at which point the lines become jagged again.
This happens on two different systems here, both with SW 2017 SP5 but one system has an Nvidia GeForce GTX 650 video card and the other a Quadro K2000. It's my understanding the two cards (coincidentally) have about the same graphics chips but the Quadro performance for CAD should be significantly higher than the consumer or gaming card. However, my question has nothing to do with the two cards (or maybe it does?), it's just that that is what we are using.
Despite the highest quality settings being used in SW, at least with the GTX 650 card we can use Nvidia Control Panel > Manage 3D Settings > add Solidworks under Program Settings and significantly tweak the settings to get a MUCH smoother line quality. However, these settings, although they dramatically improve the apparent quality, do so by blurring the lines making them look smoother on the screen although this is without SWs internal help, which we ultimately want. The result, and the reason we don't use this method, is that EVERYTHING is smoothed/made 'fuzzy'/blurred including text on drawings or dimensions and that's just unacceptable.
As I said, the image quality settings are maxed in Document Properties > Image Quality.
If anyone has the same problem or if it's not an actual problem just a misunderstanding of what we're seeing, I really would appreciate your input.
The images are closeups of a simple steel rod part from an assembly that has the 'Nickel' appearance applied but different materials or appearances do not seem to matter, the issue is the same whatever we try. I apologize if the question is already answered somewhere here but I searched and didn't find a duplicate.