Hi all, Around May 2010, I ordered a 27" iMac (Mac OS X 10.6.8) with the following specs: Code: PROCESSOR 2.8GHZ QUAD-CORE INTEL CORE I7 MEMORY 4GB 1066MHZ DDR3 SDRAM - 2X2GB HARD DRIVE 1TB SERIAL ATA DRIVE GRAPHICS ATI RADEON HD 4850 512MB OPTICAL DRIVE 8X DOUBLE-LAYER SUPERDRIVE MOUSE APPLE MAGIC MOUSE-Z APPLE SOFTWARE - IWORK NONE APPLE SOFTWARE - FINAL CUT EXP NONE APPLE SOFTWARE - APERTURE NONE APPLE SOFTWARE - LOGIC EXPR NONE APPLE SOFTWARE - FILEMAKER NONE APPLE SOFTWARE - MS OFFICE NONE APPLE KEYBOARD & USER'S GUIDE WL KYBD & USER'S GUIDE-PO COUNTRY KIT COUNTRY KIT,IMAC 27-INCH-PRT Until yesterday everything was running smoothly, but around midnight the electricity went out, came back for a split second and was gone again. After that, I took out the plug from the electrical outlet and went to sleep. When I woke up this morning and turned on the computer, I noticed it took much longer than usual to boot. Also, it took a few additional minutes for the "I'm doing too many task at once" noise to go away. Besides playing Starcraft 2 on low graphics, using a bit of Photoshop here and there, the occasional Screenflow high definition desktop recording and Premiere video editing, I don't do much cpu intensive tasks these days. A user somewhere recommended to go to System Preferences > Startup Disk > Select Disk and click Restart. And it seems it solved the issue. At least, the boot is faster now. I decided to reset my PRAM and NVRAM. I'm not sure if it helped, but now the boot takes only around 30 seconds. I'm happy. Still, my CPU idle usage is still at 90-100% all the time, even when I have no applications open? Is this normal? I turned off Airport to see if the high % idle CPU usage would go down. No luck. After that, I checked Activity Monitor > All Processes. Everything seems fine, most of the values don't even reach 0.5% CPU usage. The top processes (usually Activity Monitor or Google Chrome) spike at 4-5% usage for a split second. Maybe I'm overreacting, but I just want to be sure this couldn't cause some future problems, especially because the warranty is almost over. Thanks for the help. P.S: Not sure if it helps, but here's a screenshot from iStat Pro with only Google Chrome open. Edit: Added screenshot.