Hi Luis, I fitted one last week. I am very pleased with it. My Cube had a 500Mhz chip. The instructions were OK. The procedure requires that you first upgrade the firmware. A separate CD is supplied for this. I had a self-inflicted problem with this stage - I still use my old SE keyboard through a Griffin iMate in preference to the standard USB keyboard - the firmware update does not happen properly with this KB but worked first time with the USB KB. I have no thermometer to measure temperature accurately, but my subjective judgement is that, if anything, it runs cooler than the 500MHz chip. I concede that I might have a vested interest ! I see no reason not to recommend the chip - as I said. I am very pleased. All my software now runs natively in MacOSX, and for the odd occasion I am content to use Classic - so I have not bothered to run the OS9 software boot patch, which comes with the CD. For those wanting to boot regularly in OS9, there would appear to be no problems other than the certainty of losing the boot patch when Zapping PRAM - which means a reboot in OSX and re-running the patch before rebooting in 9. Happy to answer any further questions. Oh yes, you'll get a quality screwdriver ut of the deal! David On 30 Sep 2004, at 10:47, Luis Meleiro wrote: Hi Listers, Anyone here tried the new GigaDesigns 1.3 GHz fanless CPU for Cubes!? < http://www.gigadesigns.com/productsM71213CN.html >