The Inq reports the Radeon X1800XL and the dual-slot cooled Radeon X1800XT graphics cards from ATI can get quite noisy.
When you boot a Radeon X1800XT you will hear very noisy sound for a few seconds until the board boots but after that you are more and less fine. However the cooler will periodically start spinning faster making the machine noisier although it will get into low-noise state just shortly after. We heard this before with Radeon X850 XT PE cards.More info at The Inquirer.
Same stuff occurs with Radeon X1800XL, the one that you can buy in both USA and Europe as we speak. Visually almost identical to that used on the rival Geforce 7800 GTX, the cooling is periodically spinning faster and therefore acts as noisier solution.