Howq to keep up voltage on the 5v rail

wvjohn · Post by **wvjohn** » Wed Feb 05, 2003 9:09 pm

this was never really an issue for me until I got into the 2100+ tbreds - I seem to be having a recurring problem when overclocking 2.4 GHZ plus, that I will get spontaneous reboots - everything else is well within spec - temp 42C under load @2.3, 1.85 v. - using a medium quality 450W ps my 5v rail is down to an average of 4.87 at 2.26Ghz and a little lower at 2.4 ghz+

system 8rda+ rev 1.0, 1 gig mixed pc2700/3200 60gb maxtor 7200, 80 gb maxtor 5400, dvd , cdrw, 8500 - except for mouse, usb devices are run off a powered hub

there is an interesting article on the from page at overclockers.com (not linkable) which discusses the relationship between more memory and more power usage

if there is a way to get the 5v rail back in line without spending a huge amount of money on a 550 w top of the line ps, i'd love to hear about it

I have extra power supplies laying around and wonder if it would be possible to take one, short the on off pins, and use it to power the drives and fans

anyway TIA

been surfing around coupla interesting links -

http://www.8rda.com/

http://members.cox.net/psj4/

it seems that the steppings on the northbridge also make a difference in the oc potential of this board - i have a new one and i will have to check

PreDatoR · Post by **PreDatoR** » Wed Feb 05, 2003 9:47 pm

i'm having that problem right now too John...

with my 480W True Blue Antec i hover at 4.81 at 2.2 gig

with this 420W Vantec Stealth i'm at 4.73

this is on the 8k3a+ and its hard on the 5V rail so i'm hoping this 8RDA isn't as rough. even at 2.2 gigs about once every 3 days i get a spontaneous reboot out of no where..

honz · Post by **honz** » Thu Feb 06, 2003 1:09 am

so spontaneous reboots are usually caused by bad 5v rails?? reason i ask, is a friend has a prob with it. tried everything, but he couldn't figure out what it was, lol.

b-man1 · Post by **b-man1** » Thu Feb 06, 2003 1:23 am

get one of the super power supplies coming out from antec...tweakable voltages!!

antec PS

Antec TrueControl 550 PSU:

(Blade posted this link in a previous thread of mine...thanks Blade!)

PreDatoR · Post by **PreDatoR** » Thu Feb 06, 2003 1:37 am

that would be nice but if you ask me that panel looks ghey... i'm thinkin' about opening up my 480W and seein' if there is a pot in there i can tweak to getthe 5vup... wanna see what it does on teh Nforce2 first... but i'm waiting on a couple chipset coolers for it first before i can install it

Lmandrake · Post by **Lmandrake** » Thu Feb 06, 2003 1:45 am

Run, don't walk, to here

These are new old stock Compaq 300w server power supplies. Very cheap and well built. The bonus is potentiometers inside that allow you to adjust voltages.

I have one, and it has a stronger 5v rail than a more expensive Antec....

At this price, you can buy two for each of your pc's...

N0 P4 connector though...

wvjohn · Post by **wvjohn** » Thu Feb 06, 2003 10:12 am

hehe - I ordered 2 - i'll puck up some wirenuts on the way home ...thx

Pugsley · Post by **Pugsley** » Thu Feb 06, 2003 2:21 pm

even if there isnt a POT... you can still adjust it. just find the resistor that is attached to the adj leg of the regulators that are for the 5v. its a bit of an advance mod but it can be done.

RubberDuckie · Post by **RubberDuckie** » Thu Feb 06, 2003 10:17 pm

I was having the same problem. Did some research and found that some Epox board with Enermax Power Supplies have a 5v problem. I am running 4 HDDs and would get R/W errors all the time. I purchased a new Power Supply and now I am getting good voltage and my problems are gone. I installed the new Power Supply just yesterday. Im happy with it.

BTW I got the CoolMAX 470W from Newegg HERE

Tomuchtime · Post by **Tomuchtime** » Fri Feb 07, 2003 2:13 am

I wonder if it's possible to put a cap in there to hold things steady.Ive done similar things like that with 2 way radios
and had pretty good results.I'm not sure if the +5 rail and ground would be the place to start or if there's an issue with the -5v. The thinking behind this is that you don't have to kick up the voltage but it's stored for a moment in the cap and has the current to boot. 5v = 25v electrolitic @ say 220uf for starters(not the correct figure but you get the idea)
Just a thought.
Bill

PreDatoR · Post by **PreDatoR** » Fri Feb 07, 2003 2:42 am

caps help smooth out a ripple they wouldn't increase the voltage at all... they only store the amount of volts that is put into them... only way to up the voltage is to change the resistance....

Tomuchtime · Post by **Tomuchtime** » Sat Feb 08, 2003 4:54 am

Originally posted by PreDatoR
caps help smooth out a ripple they wouldn't increase the voltage at all... they only store the amount of volts that is put into them... only way to up the voltage is to change the resistance....

I'm not trying to imply a voltage increase
in my suggestion. Storage - if only temporary of the 5v is what I had in mind
to keep an even steady flow to the load.
The ripple effect has been mostly taken care of at the p/s itself by design. I'm just suggesting a secondary storage area that would also handle the current demand for the fraction of the cost of an upgrade.Like I said it's just a thought.
bill