Ok so every game I've installed and played has crashed over and over some less frequent that others. One game popped up and said I only had 3600MB of Ram and it requires 4096mb. I have installed 8GB of RAM. I've pulled up my PC performance manager and it's reading the full 8192Mb and have 4610 reserved I know the last stick I bought is a slower speed than the performance 4GB i put in was just on a budget and thought any more couldn't hurt the system or was I wrong and need to buy the same brand and speed?