I have just fitted an Antec 430W TruePower PSU to my system, and I'm disappointed. Now I'm trying to work out whether for some reason my hearing is finely-tuned to the noise it's making, or whether I have another faulty PSU. The first one I had seemed to be under-delivering on all voltage lines with the effect that my computer would randomly reboot. I know it was the PSU because I swapped it for a spare Chieftec 340W PSU I had, and it worked fine, but it was too noisy, and I thought, and was advised, that the Antec PSU would be better. Here's my system spec: Chieftec DX-01WD midi tower case Antec 430W TruePower PSU ASUS A7V333 motherboard 1 x 256Mb Samsung PC2700 DDR SDRAM AMD Athlon XP 1800+ CPU Zalman CPU flower cooler (heatsink and 92mm fan) GeForce 2 MX400 graphics card SoundBlaster Live! 5.1 sound card Zoom V92 PCI modem TrendNET network card I don't have any other fans except the two built-into the PSU and the Zalman CPU fan. Originally, I thought the noisy culprit was the graphics card fan, but I temporarily stopped it, and the noise remained. I did the same with the CPU fan, and still it made no difference. Sadly, it seems that the PSU fan is the problem. It emits a high-pitched noise, which seems to be mechanical rather than aerodynamic, suggesting that the noise is being made by the physical parts of the fan rather than the air it's shifting. I am running ASUS Probe software to monitor voltage, temperature and fan speed, and the PSU fan speed is being reported as 1600rpm after about an our of uptime. The Zalman fan is running at 1500rpm, and is much quieter. Now I know that the Zalman is a 92mm fan, but it isn't making any mechnical noise, only aerodynamic noise. There are two fans in the PSU - a 92mm inlet and an 80mm outlet fan. I think that the outlet fan is the one causing the problem, but can I do anything about it? I don't really want to take the PSU back again, because other than the noise it's working fine, and I know it's going to supply all the power needs of my system for quite some time to come, but if it's always going to be this noisy, it's going to drive me mad! Does anyone have any experience with this particular PSU, and if so, have you been disappointed with the noise it makes? I'm trying to work out whether mine's faulty, and if it isn't, whether there's anything I can do to make it quieter. Obviously noise is subjective, but I can't believe my hearing is *that* good! I live in the UK - does anyone have any suggestions how I can measure the noise it's making so that I can at least be objective about its performance? I have had a look for decibel meters, but I can't seem to find anything suitable. Please shout your replies - I'm going to put my earmuffs on now..!