Issue with PCI_Express slot?

Check that your power supply is properly grouding to your case; many PSUs are anodized aluminum, and the damned screw holes get anodized as well - looks pretty, but anodizing is an insulator - I always do this:

Thanks for the answers,I have had my power supply for about 2 months and the problem has gradually gotten worse so it makes sense it would be the power supply I tried grounding it out like you said and switching connections and still had the same effect,what power supply would you reccomend so i wont have this problem again

Something I was wondering about in BIOS I have PCI express frequency option to set the clock between 90mhz-150,default is 100.
Also I have a clock drive setting that is default at 700mv in the owners manual it says default is 900mv so i set it to that it made a little difference but still the waves on my screen,do you think adjusting these will help?

If you're not OCd, the PCIe will work correctly at 'auto'; if you do OC, I recommend setting it to '100' (not 'auto'), and the auto divider does not work correctly for some chipsets at higher than stock Bclk...

Don't know about adjustments, as I haven't yet fathomed what might be wrong. My only experience with noisy components has been limited to bad, or poorly wound, inductors, and ground loops. You say you hear and see this playing games - does it only happen in games? Does it happen in every game you have? Do you ever get it in the OS, say when you're crolling a PDF? Are you sure it's 'comming from the slot'? The fans are usually PWM'd at a high audio frequency, and they might 'ring' at the switching frequency...

I don't know that it can really be a power issu, as tou get it with both cards, and the 4830 should lessen, if not eliminate it, if that were the issue. Have you tried changing to the other PCIe x6 or x8 connector on your power supply?

It only happens when I play games, and my HD4830 originally didn't have to problem but it recently started doing it.Al the fans normally run at a low rpm do to the case i have. The 4830 doesn't make the sound as bad and if I put everything on
low settings theres no sound so after hearing its a
psu issue it makes sense that would be it
I picked out Corsair CMPSU-750TX 750-Watt TX Series from the ati/amd website as being about the cheapest i can afford right now,is it a good psu?

Leaving 'headroom' for another vidcard in Xfire, a CPU overclock, and four DIMMs, I get around 500 watts, so a 750 should be great plenty... Whether you get a 650 or a 750, I would look for something with four PCIeX6, or two PCIeX6 and two PCIeX6+2 or 8's, just so you're 'covered' in case you want to add a second 5870 someday, either to Xfire for gaming, or to do this:

Corsairs are great, but a bit pricey...

I borrowed my cousin's roswell500w power supply and put it in tonight and it fixed the problem I was having so i ordered a new power supply thanks for the help.

Best answer selected by bran101010.