Total power system usage



My computer specs are as follows could someone help me figure out how much power my system uses and maybe what the different components use individually? Thanks, I tried doing research but no one seems to have the power usage listed on their websites.

I am using a 350 watt power supply that came with the case, apex is the brand. My system is using the following components:

Amd Athlon64 3500+ Oc at 2312 Mhz
1GB of Ram
Nforce 3 ultra Epox MB
1 system fan in the back of the system
Ati RAdeon x800 xl agp version so it has molex connector
2 dvd writers
Tdk 440N
Plextor 740
Audigy 2 sound card
Logitech 3100 series mouse and keyboard wireless
Epson printer usb
Canon lide 35 usb powered scanner/ no power adapter required
Once in awhile ipod is plugged in to be charged
once in awhile a usb key is inserted
once in awhile a camera is plugged in to load photos.
once in awhile a camcorder is plugged in firewire

The reason I ask is sometimes I have a blue screen system crash that happends once in a blue moon when I eject the cd rom tray in the tdk burner. I also have periods where my system stalls but this also is very rare.

Any help you guys could give would be greatly appreciated! Thanks


A utility like speedfan or everest will give you a better indicator of whether or not you are having power supply problems. Having stable power is more important than total number of watts. Monitor the voltages across the 12v, 5v and 3.3v rails while the system is under load for fluctuation.

Also while troubleshooting, you may consider running your CPU at it’s default clock speed, to eliminate that variable.


Could also try Motherboard Monitor if it’s compatiable with your board. Monitors voltages, temps, etc.


I would say that your power supply is defanatlly a likley cause. I’m pretty sure apex is the same as allied and they are pretty crappy (typical for power supplys that come with most cases).

Here are a couple of power supply calculators to get a ballpark figure

Some more info

Your drives (optical or hard disk) should list power requirements on the label.
I would defanatlly recomend a better and possibly bigger power supply, especially since you are overclocking.

Checking voltages like others have recomended is a very good idea too. If possible, check them with a multi meter, otherwise use software as recomended and check them under load, not just while idle.


That’s exactly what I was looking for, thank you so much ripit!


I checked out the amperage of my psu. the +12v rail provides 16amps it says. Is that enough? When I went through the estimators that were mentioned it said I should only need roughly 330watts at full load. I read somewhere that typically a psu rating is not always accurate. That it is the best case scenario and when it’s cold. As it warms up the effective rate drops considerably? If you have any advice and you want to email me directly it’s


16A on the 12V rail is definitely not sufficient to run an overclocked A64 CPU, X800XL and all the other components in your machine. you’ll need a bare minimum of 20A on the 12V rail and ideally something closer to 30-35A…


cheap power supply ratings are not accurate (and cheap power supplys often don’t supply stable voltage which is very important). That Crappy allied probably puts out 16 amps for a few miliseconds till its own heat starts reducing its power output. In reality it can probably only output half that at operating tempature and you are defanatlly starving your system for power. If the power supply calculators say you actually use 330 watts, I would go with a 400watt or biger. It leaves room for error as the power supply calculators use average values for some equipment, it allows the extra power you need for overclocking, and allows extra power for usb/firewire stuff plus future upgrades. As drpino has pointed out, the 12v line is the most used and most important. It’s as important if not more important to look at that as opposed to total watts. The power ratings on good quality power supplys can be trusted. I don’t think I would run 12v 20 amps on that system overclocked. Thats cutting it kind of close.
How much do you want to spend? If you want to go cheap, fortron is about as cheap as you get for a good one. Maybe something like this

I have one of these and think it’s pretty good for the money.

One thing to check into though is what power conectors it has. For instance if you have a lot of sata drives, see how many sata conectors it has. If your motherboard has a 24 pin conector it’s gotta have that (many have one that can do both but not all do).

some other good brands are enermax, ocz, pc power and cooling, seasonic, sparkle (same as fortron) and others. There are defanatlly plenty of brands to avoid too.

Here are some recomended power supplys.


In regards to finding a power supply that has a higher amp rating on the 12v rail, at most of the power supplies say they are over 400 watts but end up having 12amps at the 12v line. I found that the one in my case seems pretty nice compared to some psu that were 20-40 dollars. The case I bought was only 40. Does anyone have a recommendation for a good psu?


How much do you want to spend? I think I might have edited my post after you read it (there is a link at the end with some recomendations). One other thing to be aware of is some power supplys have dual 12v rails, so look at the label (newegg usally has pics of the label) to see what the total 12v output is.
Looking at all power supplys on newegg in the 401-450 watt range, the cheapest that I would recomend is the fortron that I originally linked to. There might be something a little smaller. I would rather go with something a little smaller and good than a little larger and crappy.


OK, thank you for the advice. So do you think there will be anything noticable with my system if it is receiving enough juice where as before it wasn’t? I will look at getting something with at least 20-25a on the 12v rail hopefully that will be enough.


First off it should stop the crashes unless windows has coruption, which can happen when it has crashed several times. If there is coruption, a repair install or clean install or perhaps if there are only minor problems, just fixing the problems will end it once there is enough power. You might get lucky and windows is fine. Some burners have been reported to have poor burn performance when underpowered (I think lg’s may be one of them but I’m not sure). You might get improvment with your burns, you might not.
The bigest thing you are gaining though, which you might not notice but it matters, is that your equipment will most liklly last longer. Even if they power supply didn’t fail, under powering equipment can cause it to prematurlly fail. Overloading a power supply can cause unstable voltage which can really be hard on your equipment. You might get beter overclocking. You avoid the risk of the power supply (which was being pushed beyond what it could handle) dying and taking parts of your computer with it (I have had that misfortune with a piece of crap generic power supply that claimed to be 500 watts). Beyond it stoping the crashing its hard to tell what you might notice from a good power supply, but trust me when I say the benifits of are defanatlly there. It looks like you have some pretty good and expensive equipment, so why risk loosing it with a crappy power supply?


Stable power is so critical to a PC. I would guess that the random lockups and stalls will be eliminated when you replace the power supply with something more reliable.





The thing I really hate about the epox nforce 3 motherboard I have is that it doesn’t support monitoring the +12v rail. It reads the 5v and the cpu and the chipset and ram and 5vsb even the vgap bus but no 12v rail or 3 v rail. I checked online and others have complained about the same thing. My psu is slightly warm with the air coming out of the back however it seems fairly stable when the probe is monitoring. I have been using the system as is since augest. I very rarely have problems but I do sometimes like I mentioned above. The psu is AUSTIN, DR-B350ATX


would a surge protector do anything?


In this example no, as the problem is confined to within the PC itself. Unless the surge protector offer’s power conditioning, at which point it has not been established that dirty power from the wall socket is a problem… well maybe just no. :bigsmile:


good PSU is everything. tho i managed to get my old dual xeon system running on a no name 320W PSU for 3 weeks till my new PSU arrived :bigsmile:

but now with my brand new Opteron 180 and 2 Nvidia 7800GTX xxx 512Mb cards im taking no risk and installed a server grade 660W EPS PSU :wink:

PSU is one of the last things you should try to safe money on.


It really is the last thing you should try to save money on. With just about anything else in your system, if it dies, it dies. If the power supply dies, it can take other stuff with it, and even if it doesn’t die, it can kill other stuff.