I just installed a new power supply in my supposedely proprietary Dell Optiplex GX620 and it's acting kinda funny. The actual power supply that I got to replace the stock Dell psu doesn't even fit perfectly into the case, it's actually a bit longer and slimmer but the screws aligned and i was able to attach it without any additional problems. The power supply appears to be working and it is definately giving my video card the extra wattage it desperately needs to perform up to its potential. It's kind of hard to explain or pinpoint exactly what has happened to my computer since I've installed the new psu but it can't be good. Basically, everything just seems a bit laggy(opening and closing applications, even web browsers). Could there be a problem with this new setup?
Here's the power supply that I got to replace the proprietary Dell one.