Stefan: Yes. The 'outlines' are indeed too closer. Mine was a PL 1,35GHz. Here's the horror story: (already published @ the list, so apologies to those of who've read it again and again) First of all, I've backed up my entire internal HD drive first, followed the manuals and VideoCD provided by PowerLogix, pressed CUDA button once, started up the Mac and both Mac OS 9 (firmware patch needed) and Mac OS X worked fine. Testing the hardware I faced the terrible issue that would lead me to corrupt my internal Seagate 80GB HD, my external FW 160GB HD and my internal iBook 20GB HD. EACH and ANY FireWire copy was corrupting my hard disks. I must underline that this took place ONLY when in Mac OS X. Everything worked FLAWLESSLY when in Mac OS 9 (including several FW copies, go figure!). YES, I've tested it with several independant FW disks and cables. Procedures (after persistent negative results)... 1. Had to run DiskWarrior on each and every hard disk in order to repair my precious and lifetime data. 2. Had to format/repartition/reinstall Mac OS 9 and X in my internal Seagate 80 GB. 3. Fresh(es) OSs now. Still no difference. FW copy crashing in Mac OS X Finder, Spinning beach ball of death, etc... 4. Removed my internal Seagate 80GB and swapped it for a Western Digital 120GB. Reistalled. No go. FW not working. 5. Downclocked Seagate 80GB to ATA66. Reinstalled. No way Jose. 6. Removed firmware patches. Put back original CPU (stock 450MHz). No FireWire issues when in Mac OS 9 or X. Cube works like a genuine swiss quartz swatch now. 7. I might consider a GigaDesigns or Sonnet next time. Not sure yet... honestly. LM >>> no-spam at punkt-x.de - 2004/12/13 13:19 PM >>> Hello friends, after a long time of waiting I decided to buy a Powerlogix 100 1.3 GHz 7457 Upgrade. Nervous and with a feeling like christmas I waited and built it into my cube. In fact: about 3x times faster than my 450 MHz CPU I could measure with Xbench. Heureka!!! But than the problems began: crashes, defect and even dead harddisks followed and so on. Be sure, I did everything like the instructions told me. Three days and tow defect HDs later I ask myself, what might be the reason. So I couldn't install more than 10.3: 10.3.2.dmg couldn't be mounted, same with installation of other software. (I made a clean install, therefore I can't imagine, that owner rights or preferences can be the reason...) As I remarked, my cube had and has Boot ROM Version 4.1.9 "f". No, back to 450 MHz, my cube works stable again. I'm quite sure, the CPU is OK. In fact it Has anybody of you had similar problems? Very interested Stefan