What isthe P9 Connector on my PSU for?


Jan 28, 2010
Are you sure ? P9 connector, could you take one photo of this please ? Normally, you have P8 (2*4) connector for the CPU, 6+2 connector for the GPU, and molex connector for HDD and other.
Must be a misunderstanding. I checked several references. The brand new OCZ Z series power supplies do not come with a P8 or P9 power cable. Instead the OCZ Z series power supplies like other modern psu's come with a 20+4 pin motherboard power cable and a 4+4 pin motherboard power cable.

The P8 and P9 power cables and connectors were common more than ten years ago. Both the P8 and P9 had a single row of 6 pins. They were the primary motherboard power connections. They had to be plugged into the motherboard so that the black ground wires of each were next to each other. When the atx standards for motherboards were revised the P8 and P9 connectors were replaced by the 20 pin connector. Another atx revision led to the 24 pin connector.

Back then some power supplies came with a third P connector power cable. It was used on a very small handful of motherboards just prior to the introduction of the 20 pin motherboard connectors. Most of the time the the third cable was not connected to anything.



Former Staff

I've seen P9 cables on server motherboards that were ATX based, prior to ATX12V. I've also seen them in LPX systems, used to power the backplane. Several of my ATX12V power supplies had these in the past so they could be used in LPX systems, and I used one of those to actually test a server motherboard!


Dec 19, 2009
Since I already have this thread going, I have another question. I have removed my old thermal paste from my cpu and heatsink, and applied some new good qualitiy stuff, similar to arctic 5. DO I need to wait a week or so to get good temps? Because I'm still hitting 60 degrees with my 955 BE at stock speed on Prime95.
Any help?
moopato - Could you please describe the OCZ Z series power cable connector you are calling a P9. How many pins and rows does it have?

The answer to your question about thermal compound is it depends. Some pastes have a curing or break-in period. Some do not. For example, the original Arctic Silver 5 had a curing period of 200 hours. I would suggest running it for a while see if there is any difference. How is your case ventilation, airflow, and cooling?
I'm wondering if perhaps there's a diagram in the manual that labels the various cables starting with P1 and going thru ....

As for the TIM curing question, I found this on bechmarkreviews which is a quote from the AS web site:


Due to the unique shape and sizes of the particles in Arctic Silver 5's conductive matrix, it will take a up to 200 hours and several thermal cycles to achieve maximum particle to particle thermal conduction and for the heatsink to CPU interface to reach maximum conductivity. (This period will be longer in a system without a fan on the heatsink or with a low speed fan on the heatsink.) On systems measuring actual internal core temperatures via the CPU's internal diode, the measured temperature will often drop 2C to 5C over this "break-in" period. This break-in will occur during the normal use of the computer as long as the computer is turned off from time to time and the interface is allowed to cool to room temperature. Once the break-in is complete, the computer can be left on if desired.

to which the author makes the following comment:


So by my estimation of this statement it would take almost a year of normal use to properly cure the AC5 compound, or almost nine days of continuous power cycles to meet their recommendation.

From the same article:

Arctic Silver II Application Instructions(48-hours minimum curing time recommended)
Arctic Silver 3 Application Instructions (up to 200-hours recommended curing time)
Arctic Silver 5 Application Instructions (up to 200-hours recommended curing time)
Arctic Silver Ceramique Application Instructions (25-hours minimum recommended curing time)
IC Seven Carat Diamond Application Instructions (10-minute evaporation time, 2-hour curing recommended)

One thing I noticed with the IC Seven Karat stuff was that once driven to high temp levels w/ some high OC'ing (4.4 GHz) profiles, the regular usage OC profile (3.7 Ghz) dropped a few degrees.