Merc
March 27th, 2007, 12:24:09 PM
Ensuring that you get steady, solid DC voltage to your CPU, RAM and other components is vitally important. The NF4 boards are notoriously picky about power and if the current fluctuates greatly or is below a certain threshold (which is WAY above the +/- 5% ATX spec) then you can get all kinds of weird and seemingly unrelated problems plaguing your system. This is why the first question anyone asks regarding strange system behavior is "What PSU do you have in there and what are its specs?" Total watts and amps on the 12v rail(s) are the primary data they are looking for with this question but the 3.3v and 5v rails are also important, although not usually as critical as most PSU's can supply plenty of DC on those rails.
So how can you tell what current your PSU is supplying and if there are any fluctuations on the rails? Well, the mobo itself has sensors that provide this info and you can read what those sensors are seeing in BIOS or via Asus Probe. Simple enough right? Wrong. Take a look at what Asus Probe is reading on the 12v rail. Is it 11.76v? A 12v reading at that level would immediately get my attention with this board but your system is probably running fine right? The A8N SLI Deluxe sensors are not at all reliable and give false readings that make them fairly useless except for seeing fluctuations.
In order to get a real reading of your voltages you'll need to get a voltmeter and go probing. This is not as daunting a task as it sounds and a voltmeter comes in handy for all kinds of things. Neither does it need to be expensive. You can pick up a pocket size multimeter (mm) at Radio Shack for about $20 http://tinyurl.com/az7hb. LCD readout, small size etc. It's a nice piece of gear and plenty for this job.
The first step is to be aware that you are using metal probes around live traces so BE CAREFUL. The second step is to remember the wire colors and the voltage they relate to:
Orange = 3.3v
Red = 5v
Yellow = 12v
Black = ground
There are two ways to measure the actual voltages:
1. You can plug into an empty molex and get a fairly good reading. Just stretch the empty molex outside the case and test away.
or
2. You can plug right into the back of your 24 pin power connector and get the true enchilada. This is very hazardous though and not worth the risk.
On your empty molex stick the red probe into the the socket with the color wire related to the voltage you want to check, stick the black in black wire socket and if testing a 12v rail set the mm to 20vDC. Now play BF2 or something else that will stress your system (a benchmark or encode a DVD etc) and watch your mm readings as the system works. Expect to see some drop in line voltage but how much is where the judgement call comes in. My PC P&C drops 1/100th under stress but it is a remarkably strong and efficient PSU. Most will drop more than that but you don't want to see more than a couple of 10ths of a volt.
The ATX spec states that +/-5% of the rated voltage is an acceptable amount on the 12v rail. This equates to 11.4v to 12.6v You really want to be at 12.1v. If you aren't sure then write down your readings and post them here and we'll take a look.
Good luck
So how can you tell what current your PSU is supplying and if there are any fluctuations on the rails? Well, the mobo itself has sensors that provide this info and you can read what those sensors are seeing in BIOS or via Asus Probe. Simple enough right? Wrong. Take a look at what Asus Probe is reading on the 12v rail. Is it 11.76v? A 12v reading at that level would immediately get my attention with this board but your system is probably running fine right? The A8N SLI Deluxe sensors are not at all reliable and give false readings that make them fairly useless except for seeing fluctuations.
In order to get a real reading of your voltages you'll need to get a voltmeter and go probing. This is not as daunting a task as it sounds and a voltmeter comes in handy for all kinds of things. Neither does it need to be expensive. You can pick up a pocket size multimeter (mm) at Radio Shack for about $20 http://tinyurl.com/az7hb. LCD readout, small size etc. It's a nice piece of gear and plenty for this job.
The first step is to be aware that you are using metal probes around live traces so BE CAREFUL. The second step is to remember the wire colors and the voltage they relate to:
Orange = 3.3v
Red = 5v
Yellow = 12v
Black = ground
There are two ways to measure the actual voltages:
1. You can plug into an empty molex and get a fairly good reading. Just stretch the empty molex outside the case and test away.
or
2. You can plug right into the back of your 24 pin power connector and get the true enchilada. This is very hazardous though and not worth the risk.
On your empty molex stick the red probe into the the socket with the color wire related to the voltage you want to check, stick the black in black wire socket and if testing a 12v rail set the mm to 20vDC. Now play BF2 or something else that will stress your system (a benchmark or encode a DVD etc) and watch your mm readings as the system works. Expect to see some drop in line voltage but how much is where the judgement call comes in. My PC P&C drops 1/100th under stress but it is a remarkably strong and efficient PSU. Most will drop more than that but you don't want to see more than a couple of 10ths of a volt.
The ATX spec states that +/-5% of the rated voltage is an acceptable amount on the 12v rail. This equates to 11.4v to 12.6v You really want to be at 12.1v. If you aren't sure then write down your readings and post them here and we'll take a look.
Good luck