i am new to PC hardware DIY assembling, and i want to find out why the PC was overheating. i got a PSU & a motherboard from 2nd hand market, then went ahead to assemble them though my Pentium Dual Core E5300 is only 65W TDP, i still plugged 8 pins in as i wasn't sure if 4 pins would suffice previous build: a 400W PSU + ECS G31T-M7 (with 4 pins port next to CPU) current build: a 620W PSU + GA-P35-DS4 (with 8 pins port next to CPU) (the brand name of the PSU is alien to you guys) after they were all set, i switched PC on, i made 2 weird observations: 1. the CPU fan lag 1-2 second until it start spinning 2. i noticed more heat generated then my previous build (the PC case directly above the PSU was much warmer than before. after leaving PC on for 1 hour, harddisk temperature also raised higher than previous build, about 3-4 degree higher. everything just got hotter) since then i have returned the PSU & obtained a refund as i believed it to be faulty, but would there be anything on my part that could have caused the overheating?
There's nothing wrong in using 8 pins instead of 4 pins. And as long as the overheating does not exceed the components specification, a 3-4 degrees raise of temperature should not worry you. It seems that your PSU is the source of the overheating. Also, the lag in CPU fan spinning is probably related to the PSU quality, but it is only a small lag and, under the circumstances, it is acceptable. You may try to minimize the overheating increasing the case airflow. Just one more fan (of 12 or 14cm) in the frontal part of the case is enough. Check the temperatures of all components (CPU, motherboard, hard disk) before and after the fan installation. As long as the temperatures of all components are acceptable, you'll be fine.
I think most every desktop I've owned had 1-2 second CPU fan lag at turn on - pretty sure that's normal. Your replacement PSU has a 50% increase in capacity. All things being equal, I'd expect it to run slightly warmer. If it were me, a 3-4 degree increase would be perfectly acceptable. You don't state what the actual temps are - there are plenty of programs that will do that. When I shop for a PSU, I stick with known brands having excellent reviews on Newegg, forums, etc. If you are looking for a larger PSU that runs cooler, that would only occur if the original PSU had poor efficiency. There isn't any practical reason to have more PSU than you will ever use, but heck, I'd be lying to claim I never did it. Good luck with the next one - let us know how it turns out.
lag is normal in a lot of fans and the extra heat is the increase in wattage most likely. Seems like a no problem to me as well. But, if it doesn't smoke light it up!
in previous build the fan start spinning once i pressed the power button, and harddisk temperature used to be steadily at 43-44 after using the new PSU for 2 hours harddisk temperature raised to 47 i admit to be harsh but any temperature > 40 is bad for harddisk and i can't take it if an upgrade mean further harm to my harddrive, so i've reverted to my previous build i was tempted to try the higher PSU as i was also upgrading to gtx 650, & i doubt my old PSU holding up to supply exactly 400W. i have just recalled testing the newer PSU on my old build (i.e. just replacing the PSU, keeping all config else the same), and it still generate much more heat. so i went ahead to return it.
Anytime you add new hardware chances are heat will increase as well. The option I would take, would be to add an extra $20 (or less) fan and mounted it for exhaust or intake, depending on how the temps worked each way. Seagate for example have their new drives at a max set to 60c, average running is between 5-50c. You can consult the manufacturer of your hdd to see max-safe-min temperatures to be sure. GL with your build.