Remember it's not just the memory that gets effected. Yeah your PCI clock will change on my old PC I got it to 36.6 MHz. You can actually seriously fuck up the PCI, if you go to high. Go up in small increasements at a time, until your PC crashes for the first time. I was messing with my PC the other day, I got a bit worried because I wanted to see how far it could go. I was changing some jumpers around, playing with them. Then every time I turned on my PC everytime when it tried to go passed the BIOS it fucked. I set the settings back to normal, I thought I had completely blown the chip. I turned on my PC again and it kept on making beebing sounds. Seriously I was worried because my PC wouldn't start. I left it for a while, let everything cool down and that. So I waited for 1 hour. Fuck it still wouldn't start up. I took out the battery on the mobo and cleared the CMOS, hoping this would work. No, I now thought my PC was truely dead. I left it over night having nightmares about it. Started up in the morning. Yes!!! It worked fine. Sweet eh? Information seems to get stored for a while.
Don't be stupid and do what I did, go slowly. OK!