Power Supply: 3.3V@40A/12V@15A or 3.3V@30A/12V@34A?

[alkemyst]

I am debating a new power supply to solve loop problems in my via motherboard.

I heard the 3.3V line is the line you want to make sure is high, and that combined with the 5V rail puts out close to at least 250W+.

I am looking at the PC Power & Cooling 425W and 510W...the 425W has 40amps for the 3.3V and 15A for the 12V, but the 510W has only 30amps for the 3.3V but a whopping 34amps on the 12V.

I am swaying to the 425W one (it's $55 cheaper too and on sale).

I currently have a PCP&C TurboCool 300.

Thanks

Chris

 

[Blastman]

A P4 CPU draws its power from the 12v rail, whereas an Athlon and P3 draw from the 3.3v and 5v rails. So the better psu depends on what processor you intend to run. Check this post out ...

here

Athlon motherboards only require ATX power supplies. The board connects to the power supply using a single, 20-pin connector.

Pentium 4 boards require ATX12V supplies. These have three connectors, a 20-pin, an extra 4-pin 12V connector, and a 6-pin AUX connector.

Strictly speaking, you can use a Pentium 4 power supply with an AMD board. It has the same 20-pin plug the Athlon boards need (plus two extras), so you can just plug that in, and leave the other two disconnected, and you'll be able to boot and run fine.

HOWEVER. The reason the P4 boards have the extra 12V connector is that the P4 draws its power from the 12V rails. Thus, extra 12V power is needed to the motherboard. In contrast, the Athlon boards deliver power to the processor using the 3.3 or 5V rails (which are powered via the 20-pin connector). P4 boards still use 3.3 and 5V power, but for things like memory, AGP and PCI cards, etc.

As a consequence, Pentium 4 boards require MUCH less current from the 3.3 and 5V lines, since they're not feeding the CPU from it. As a result, most Pentium 4 power supplies have rather low 3.3 and 5V ratings (cause they're not necessary). A *GOOD* AMD power supply will have a much higher rating on the 3.3 and 5V rails. Thus, while your P4 power supply should technically work with an AMD board, and allow it to POST, it's probably not optimal, and may have trouble with higher speed Athlons (the current draw increases with CPU speed).

As rough figures only, a good Athlon supply should have a total combined output of at least 200W on the 3.3 and 5V rails, whereas on a Pentium 4, 150W is probably more than sufficient. ? ? ? ?

 

[alkemyst]

Cool, thanks, PIII-S for me so the 425W is going to be the ticket...$143 , I just hope it solves the freaking infinite loops.

Chris

 

[Blastman]

Looking at the combined 3.3+5v ratings on a psu is important for the high end Athlons as they can draw a lot of power from those rails. In your case that 425w model will be tons of power for a P3-S as they only draw half the power (~ 32watts) compared to a high end Athlon XP 3000+ (~ 65 ?70 watts).

I?m currently running my Celeron-T 1.0A @ 1.33 with a 350w Enermax 365FMA (185watt combined 3.3+5v) and my psu probably hardly even gets warm.

but the 510W has only 30amps for the 3.3V but a whopping 34amps on the 12V.

34amps!!!. That is huge. Good psu for a high end P4?s which feed off of that 12v rail.

 

[ElFenix]

i think you're overkilling with either

 

[alkemyst]

I thought my 300W was sufficent, but it only puts 14A to the 3.3V rail and the combined rails are less than 140W.

I think going to less that 425W would be stupid right now.

I also have 2 HD, 1 CD, 1 CDRW, 1 DVD, 1 Dual PCMCIA reader, LS120, 3 PCI, 1 8500, 1 high power USB, 6 Fans including PSU and CPU.

 

[Jhhnn]

I rather doubt that your looping problem is from the psu, more likely from the soundcard, which has known issues with via chipsets. I didn't realize that there were XP drivers available for it, anyway. Uninstall the drivers and remove the card physically and in device manager. Try it- the price is right.

Your 300w is probably a rebadged Fortron/Source, extremely stout, conservatively rated. If you're not having boot problems, and the voltages are within specs, you're barking up the wrong tree.

 

[alkemyst]

At viaarena there is a big writeup on all this. The power supplies putting out less than 200W across the two rails are the culprits...so far I think everyone that upgraded decent PSU's to really decent PSU's have now had no problems.

Removing the sound card, memory, changing agp settings to minimum, going to pci video, etc are not solutions, they may stop loops, but you also have a crippled machine.

Audigy does have XP drivers, always had them, however, they were stopped mid development. The original XP drivers are the best and there is even an update to get control panel back.

The latest XP drivers cause you to lose EAX. With the originals I have had no problems in any game's sound effect/music not working.

The VIA motherboards are unique in some things.

The only time I am getting problems is during huge game screens with a ton of independent things going on.

While the PSU replace is the most expensive solution it's also the easiest....so many have spent hours and hours trying to tweak settings, change slots, etc to still have to swap the PSU.

 

[Blastman]

I thought my 300W was sufficent, but it only puts 14A to the 3.3V rail and the combined rails are less than 140W.

Those really aren?t very good ratings for a 300watt psu. Normally I would think you still should have no problem running just a P3-S with that psu, but with all the stuff you?re running and that low 3.3v 14A rating, you may be taxing that psu.

I have a few psu ratings from another post, my Enermax 350watt ? (EG365P-VE FMA) 1 year old) ? is rated ?

3.3v ? 32A ? ? ? (3.3 and 5 combined 185watts)
5v ? ? 32A
12v ? 17A ? ? ?-> 204watts

the new Enermax 300/350watt ?
3.3v ? 28/32A ? ? ? (3.3 and 5 combined 170/185watts)
5v ? ? 30/32A
12v ? 22/26A ? ? ? -> 264/312watts

Now the Antec Solution series ?smartpower ?
300/350watt
3.3v ? ? 20/28A ? ? ? (3.3 and 5 combined 220/230watts)
5v ? ? 30/35A
12v ? ? 15/16A ? ? ? -> 180/192watts

Interestingly enough, the new Enermax?s have bumped their 12v rails substantially (better for P4), whereas the Antec?s have a much better 3.3+5v combined rating (better for Athlon).

 

[Jhhnn]

Alkemyst- you never mentioned an Audigy soundcard, I took it from your profile that you were using the Aureal Vortex- Monster sound mx300, which has well documented issues with via boards.

Do what you want, of course, but there are more compatible audio solutions than the audigy available, too.

 

[alkemyst]

sorry was doing a million things at once...its an aureal vortex I have a Diamond MX300.

I also asked about upgrading in a different thread and many said they wish they kept the MX300....

A soundcard is a cheap upgrade, but the consensious said keep what I have.