I have a GTX 680 with two DVI ports and an HDMI. well lately my HDMI stopped working properly on my monitor, and the only port left on my monitor was a VGA, so i used the DVI/VGA adapter that game with my gpu and am now using VGA cable instead of the HDMI, but i notice no difference at all. i do a bunch of hardcore gaming and i was wondering, is there any real visual difference between the two? i know about sound, know that VGA is analog and HDMI and standard, etc... but like is there any actual picture quality differences between the two? google has not been very helpful with this question.
To the best of my knowledge VGA/DVI/HDMI (pre 1.4) support comparable resolutions. VGA isn't so much limited by the size of the pipe as it is the condition of it. Meaning DVI and HDMI are digital and not really affected by signal degradation whereas VGA, being analog, it can be affected by everything from PI filters, DAC bandwidth, cable bandwidth, connector quality etc....especially at higher resolutions.
Not to say the picture won't be comparable as seems to be your case.
I didn't want to muddy the issue with talk of HDMI 1.4 and later with it's much higher resolutions/bandwidth (4096 x 2160 if you can believe that!)
If you don't notice any difference, you should be fine. One thing to note, with VGA (or any analog signal), you cannot do aspect ratio corrections through your graphics card driver. Basically, if you use a 4:3 resolution (like 640x480, 1024x768, or 1280x1024) in full screen, it would be stretched to fit a widescreen monitor. Using HDMI will allow your drivers to avoid stretching and put black bars on the left and right side of the image. You should consider this only if you play lots of old games (that don't support widescreen) AND have a widescreen (16:9) monitor.