I just bought a asus 5870 video, i looked online and it must be new because there is no mention of it anywhere, i have multiple pci xpress slots i pulled my nvidia out and replaced it with this overly obnoxious card and a paycheck to boot, it makes this high whistle sound like a thin piece of paper next to a fan, needless to say i turned of pc right away, not sure if its an alarm or what, i looked at the manual and they have a short 4 step installation with a pic of a 10 year old video card on it, has nothing to do with what im doing, and the 2 disc that came with it are totally different. the old nvidia i had wanted you to install the drivers first, and this card wants me to install em after i install the card.
My question is if i have multiple pci slot, could the nvidia driver be programmed to that specific pci slot and i need to hammer the 300lb asus card in the slot below it or what? and i dont know where you go to buy this card for $399 like on you post, but it was much more than that, i should tell you what i have before you respond so i hope its something simple so here i go.
asus m4A.. deluxe
asus eah5870 graphic
maxtor 80, seagate 320
Coolmax 950 watt
That "whistle sound like a thin piece of paper next to a fan" Im thinking is the fan on the 5870 just running at 100% from what I can tell from your description, but I could be wrong. Try booting into windows and if the sound dose not lessen by that time then something is wrong.
To answer your question about installing the card, and since you are switching from an Nvidia card to an ATI card it is best that you uninstall the Nvidia drivers and use driver sweeper to clean the residual drivers before you take out the Nvidia card and put in the 5870.
And you question about running both the 5870 and the 9400gt in the same computer, It is possibe but only if you are running Windows 7 as it is the only OS that can handle running two sets of video drivers.
I heard a similar sound installing my new HD5850. have an ASUS P5Q mobo. It was a high pitch whistle sound. Turns out it was an alarm that went off because one of the 2 6-pin connectors was not completely plugged in. I pushed it in again, and it went away. I thought it was my fan at first. Make sure all your connections are good. IF you can get it running, change the fan speed on the card and see if the pitch changes.