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What signals that you need more power?

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GTac02

Member
Joined
Aug 7, 2003
I mean, people always ask is ***w enough? Well has anyone ever reached the potential of a 300w psu? for example. I really dont think a 400w+ psu is necessary if you are running 2 cd roms, 2 hdds, 4 fans, and oc's p4, i mean 400w is ALOT! am I wrong?

Well, what happens when you need more power? anyone experienced a case where they needed more Watts? how did you know you needed a better PSU?
 

dalilman52

Member
Joined
Jun 26, 2003
Location
Houston
what happens when u need more power is that for me, my +5v drops down to about 4.83 (not very good) and the +12v goes a bit higher to around 12.29 volts

and actually 400w is not that much, 350w is basically the bare minimum when running an oced system, especially with extera stuff like fans and more than one HDD

watts isnt that big of a deciding factor of buying a psu, the volt rails, and the quality of the psu is a bigger factor than just wattage, in most cases a generic 500w may not even put out 400w

read HERE and ull see what i mean, some good brands are fortron, antec and PC P&C, pc power and cooling (the cadillac of psu's)
 

L337 M33P

Member
Joined
Jun 5, 2003
Location
TEH INTERNETS
When you load a PSU to the max several things can happen

  • Blowing hot air out of the back - the heatsinks are getting a little warm as they were only designed to dissipate x amount of heat
  • Noticeable sag in voltage rails confirmed with a DMM at a Molex between idle and load
  • a more thorough method of testing would be to calculate the current draw on each rail, then vary the OC/number of hard drives and plot a graph of measured voltage versus load. If the line of points starts to sag at the end then you are overloading the PSU
  • noise coming out of components - squealing or whistling - high amounts of current with high-frequency components can cause all manner of noises.
  • the PSU emitting smoke and flames?
  • Occasional poweroffs - i.e. when burning CDs, gaming and defragging all at once - the PSU shuts off because it detects an overload

Most desktop systems draw ~200W for high-end P4s, but overclocked systems typically take much more juice.

My own personal experience was this:

I have a 300W Sirtech that came with my OEM system. Runs great, decent PSU but after I upgraded and started to OC I noticed a little sagginess here and there - went to the almighty Goopsulator and calculated my wattage consumption at it was about 240W - hmm :-/ so as I am going to overclock a hell of a lot more and add lots of stuff I bought a 400W Fortron.
 

larva

Inactive Moderator
Joined
Jul 12, 2002
I need to revise my power supply sticky linked above, it is now a full year old and is a bit out of date in some respects. When I wrote it I hadn't seen the need for a 400W supply yet, but have since. Here's the scoop:

It doesn't really matter very much how many drives or fans you have. Everyone here has a ton, and they don't draw much power anyway. So having a couple of optical drives and a couple of hard drives hardly makes a special case.

What does matter is the cpu. These day the power drawn by the cpu is immense, and tends to dominate the power-consumption picture. Both P4s and AXP's are powered off the 12V rail these days, but the P4s are drawing more. All but the most extreme AXPs run fine off a 350W fortron, but there are some that do benefit from a 530 fortron or 430 True Power.

P4s on the otherhand, really need the bigger supplies if OC is important. As you exceed 3GHz the load on the 12V rail generated by the cpu exceeds the capacity of the 350 forton and makes the 530 or TP430 essentially mandatory. And let's face it, if you have a recent P4 that isn't running in excess of 3GHz, you have a real under-achiever.
 
OP
G

GTac02

Member
Joined
Aug 7, 2003
Well, thats what i mean, you can run a 350w but the lines will go "unstable" then I guess?.
 

wanna_b_rich_13

Member
Joined
Dec 15, 2003
I seen a site a while back where it had a huge list of many components that you could have in your PC and once you chose everything it gave you a gernal idea of how much power you used and what was recommeneded. If I can find it I will post it unless someone else seen it.
 

gungeek

Member
Joined
Sep 4, 2003
Location
USA
After putting together a watercooling system, I started pushing the xp2500 overclock.

At [email protected] V , the system is Folding stable for weeks without a reboot, dropped WU, etc using either air or water cooling. With water, when I push it to [email protected] V, I get random reboots after 20 minutes or so but it seems entirely stable until the reboot. CPU temps aren't the problem as the die was warmer at 2.4GHz on air than 2.5Ghz with water. Setting the cpu voltage to 1.83 V makes the random rebooting start after 5-10 minutes which is the opposite of a stability problem needing more Vcore.

I'm speculating the Enlight 300W power supply is heating up causing the rebooting. I haven't put a DMM on the +5V and +12V rails since watercooling, but may soon just to verify the cause.

Maybe santa will bring a 350W Fortron PS for Christmas. Until then, I'm stuck at 2.4GHz.
 

JohnnyTheRed

Member
Joined
Aug 9, 2002
Location
Brockton MA
wanna_b_rich_13 said:
I seen a site a while back where it had a huge list of many components that you could have in your PC and once you chose everything it gave you a gernal idea of how much power you used and what was recommeneded. If I can find it I will post it unless someone else seen it.

http://www4.tomshardware.com/

They had a list a while back. not sure where exactly. But it was somewhere there.