PSU EXPERT HELP ADVICE

[edjal]

I have a Pressario 8000T-P8657A P4 3.0 800/mhz  3Gb PC3200 Ram  Asus P4SD-LE Motherboard with 2 Hard Drives, 2 opticals, multiple PCI cards and multiple usb devices.

 I am in the process of upgrading AGP Card and PSU. My OEM ATX PSU Hi Pro pn 5187-1098 had 3.3v 20A & 5v 30A rails with a 12v 14A rail.  Im looking at the 80+ effeciency Corsair 400Cx and the OCZ 400w PSU's and they have considerably less power on the 3.3v and 5v rails and a lot more power on the 12v rails. (Corsair 3.3v  20A and 5v 20A rails, 12v 30A)   The OCZ 3.3v 24A, 5v 15A, 12v1 17A, 12v2 14A.  MY QUESTION IS do I need the power on the 3.3 and 5volt rails that the OEM PSU supplied or will the Corsair or OCZ work well ?   Thank You   Edjal

[tvccs]

I'd suggest you'd have better luck with something that technical at a hardware forum like Tom's Hardware or a graphics forum like Guru3D.  Good luck.

[gkdiamond]

The only place I seen a significant difference is on your old power supplies 5V rail and that 30 amp figure doesn't even look right. When you decide on your graphic card you can look at the requirements but as long as the 400W is enough for your system and the graphics card you should be just fine.

[edjal]

Thank you for your advice. I was concerned after reading some internet info I read stated older motherboards used more 3.3 and 5v power than newer boards. When I saw my oem power supply was loaded on the 3.3v and 5v rails I wondered if my P4 was considerd in the older class or the newer class that didn't require as much power from the 3.3 and 5v rails.  I hate to purchase something then have the hasle and expense of returning.  In any event I really do appreciateyour advice                    Edjal

[c0rnel · Accepted solution]

I recommend you get a single rail power supply with good amperage at least 400W and it will be just fine.

You won't need to worry about connections or voltages.

Both Corsair and OCZ are good power supplies. I think corsair would be a slightly more favorable choice depending which one you pick.

Try checking newegg.com or tigerdirect.com for parts. 

[edjal]

I am happy to reply I purchased the Corsair 400CX PSU and installed. The Compaq computer case was proprietary and had an adaptor plate to PSU. The old and new PSUs had identical bolt patterns but the Corsair 115v receptacle was in slightly different location and the new PSU had on/off switch. I had to modify the HP adaptor plate by cutting away some material to allow for 115v receptacle and the corsair power switch. The Corsair had more area for surface air on back of computer so I cut away more material on the adaptor plate to allow for that. I did the cutting with a Dremel tool and filed it smooth. There were plenty of plugs and long enough leads for all devices. I also installed a new ATI 3650 GPU The computer now runs Quieter and seems to respond much quicker. No more boot ups for no reason.

[gkdiamond]

Glad to hear no more problems and everything worked out for you. Sounds like you did a nice job, I love my Dremel tool!