Will my (450watt) PSU survive in a Dually AMD System?

[Tim_axe]

I am going to be getting my computer from NewEgg sometime next week. (Specs provided in Takaman's calculator link) I did the very slow payment method... Anyways, I have a 450 watt Rhycom PSU. (My friend gave it to me, it came with his $30 case...) It delivers:
+3.3 - 26A
+5 - 35A
+12 - 15A
-12 - 0.8A
-5 - 0.5A
+5VSB - 2A

I think that the amperage for the +12 is rather low at 15A. According to Takaman's PSU Calculator ( My Link: http://takaman.jp/D/?M=PbbHKcHARLgHJTzUJUaXhYBYaZBZavPHOP&english ) I need to be safe somewhere around 25A on the +12.

But, if I select the option without the 12V ATX connector (The P4 2x2 Plug?) my +12 is nice and low at 8A, but the +5 is around 45A. ( http://takaman.jp/D/?M=PabHKcHARLgHJTzUJUaXhYBYaZBZavPHOP&english )


The total power requirements come in at about 350 watts. But with an unearthly amount of load on either the +5 or +12. Will my 450watt PSU survive this without releasing the magical smoke? What PSU do people with Dually AthlonMP rigs run?

I don't want to spend too much money on the PSU, but I might consider this one ( http://www.newegg.com/app/ViewProductDesc.asp?description=17-104-968&depa=1 ) if it is recommended. And how do you adjust the pots to get the right amperage for that +12?

[Koslov]

mate, don't settle for a crap PSU. It will come back haunting you for the rest of your life.
Antec Truepower or the newest Enermax series are pretty good. You might als want to consider Fortron 530watts PSU, Strong and very reliable!

[Ice Czar]

a good read
A Different Perspective on Power Supplies (http://sysopt.com/articles/PSU_Perspectives/)

How much power do you need? Looking at UPS readings from various high-end P4 systems, I’ve found 200-250W is the norm. Lesser systems use less power. So why must people buy power supplies of 350W or more rated capacity? Factors include:

When you turn on your computer, the drives and fans draw more power as the motors try to spin up to full speed.

Some applications use parts that otherwise sit idle; when these parts become active, they draw more power.

Most power supplies are rated at peak output and will overheat quickly if forced to maintain those outputs for more than a few seconds.

Some power supplies have too little output on the 12v line for the latest hardware.

The 3.3v and 5v lines of a power supply are often combined. Drawing too much power from the 5v line with devices such as CD burners and other drives can reduce the output of the 3.3v line below what is needed for devices on the motherboard.

and most power supplies are rated at 25C whereas your operating temperature is going to be closer to 40C
that represents a decrease in actual capacity of approximately 30%

especially on a dually board, dont get cheap with your power



What PSU do people with Dually AthlonMP rigs run?
ATX12V (2.01 or 2.03), EPS12V, ATXGES

you really need to triple check this ;)
they aint cross compatible
what board is it?

I have to go right now, but when I get back I'll run down exactly what you need
and give you a hand picking a supply ;)

[Vertigo Acid]

The FAQ has info about the ATX-GES, and the differences.

I run a Vantec Stealth 520w EPS12V in my dualie, and many people over at 2cpu.com run heroichi and tagan units.

[Tim_axe]

The board is a Gigabyte "GA-7DPXDW-P" -> 760MPX chipset

I never knew there are a ATX-GES or all of that before :eek: Looks like I'll definatley need more help with the powersupply than I thought... I still don't know what the gigabyte board uses since none of the web sites I've run across mention anything about it. Thanks Ice Czar, good read.

I guess it wouldn't be a bad idea to be willing to spend $80-90 on the PSU if it will last me a long time and be around with me some time down the road for other upgrades. I just thought that the cheaper ones could last fairly well, just with bad voltage regulation...guess not...

[Ice Czar]

the good news is that it uses a standard ATX power supply
the bad news is why it does...cost

AMD requires ATX12V, or ATXGES for all Athlon MP SMP capable motherboards
and so that isnt an AMD recommended board
in addition it seems that a number of people have issues running XP on that board
most I read all reverted back to W2K and the istability problems disappeared

http://www.amd.com/us-en/Processors/DevelopWithAMD/0,,30_2252_869_965^978,00.html
http://www.amd.com/us-en/Processors/DevelopWithAMD/0,,30_2252_869_965%5E3238,00.html
under the circumstances Id recommend as powerfiul and as stable a PSU as possible
in an attempt to forstall any issues, and that would be all that cheap
Id say get a PC Power & Cooling 510 ATX Deluxe

Id do some heavy reading
http://forum.oc-forums.com/vb/showthread.php?s=&threadid=238422
http://forums.2cpu.com/search.php?action=showresults&searchid=580078&sortby=lastpost&sortorder=descending
http://forums.2cpu.com/search.php?action=showresults&searchid=580086&sortby=lastpost&sortorder=descending

[Tim_axe]

The PC Power & Cooling 510 ATX Deluxe, at $200, is definately out of my budget. I must have been too trigger happy for the PSU calculator and wanting the overhead of a +12 @ 25A. I guess a more reasonable +12 would be @ 21A or 20A. I could loose a CD-ROM drive if it would bring down the cost of the PSU enough.

Can you please decypher this output for the Fortron PSU - "+3.3V@30/17A,+5V@44/24A,-5V@0.3A,+12V@16/28A,-12@0.8A,+5VSB@2A"

Does it mean that if the +5 and +3.3 volt rails are at their minimums (24A and 17A respectively) that the +12 rail can be at 28A?

And would you recommend the 530 watt Fortron PSU in my situation? Quite a few people seem to love it, and I'd be willing to spend the $75 on it and $6 shipping from the Egg...



PS, thanks for those links. I have heard that the Promise RAID controller is pretty buggy on the GA, and found some other stuff I didn't know about. But I'll stay with it, and just hope that mine works with stability...

[Ice Czar]

the fortrons are good budget PSUs
however at nearly the same price point for amp distribution you can get into the Antec True Power Line
where youd get 3% volyage regulation (compared to the Fortron 5%)
and dedicated rails for the 3.3v & 5v (whereas they are combined in the Fortron)

Does it mean that if the +5 and +3.3 volt rails are at their minimums (24A and 17A respectively) that the +12 rail can be at 28A?
there should be a note where it says something like
+3.3V, +5V and +12V total output cannot exceed _________
It means they tested that rail when there was next to no load on the other rails
(but the 24A & 17A arent the minimums)

(The following isnt a slam of Fortron, but gives you an idea of how other manufacturers test PSU and would often reflect the typical proceedure, Fortrons when tested in most reviews underestimate thier amps and total watts)

from dansdata (http://www.dansdata.com/top420p4.htm)

Unethical PSU Marketing 101.

Here's how to make overly optimistic power supply specifications. It's really simple.

First, power the thing up. You can make an ATX power supply that isn't connected to a motherboard turn on by grounding pin number 14 on the big motherboard power connector. It's easy to spot that pin, because it's the only one with a green wire going to it.

Use any handy bit of wire - like the paper clip in this picture - to connect pin 14 to any ground contact. The ground contacts are the ones with the black wires going to them. Presto, the PSU will turn on.

Now, break out your brick-sized power resistors and load the heck out of one of the output rails - the +5V rail, for instance. Measure the current as you increase the load, until the voltage sags unacceptably far below the rated voltage.

How do you tell what an unacceptable voltage sag is? Well, you could choose a nice conservative small permitted sag - say, 0.1 volts - so that your results are genuinely useful to your customers. Or you could just ignore the voltage and say that when a fuse (or some other component...) blows, that must have been the limit, right there.

OK. Now you've made a big fat amperage number for the +5V rail. If you blew up the PSU in the process, get another one, and repeat the process for +12V and +3.3V, and for the low current rails as well.

On no account, though, should you test more than one rail at a time. This is the key to the whole scam.

A big beefy PSU may be able to deliver 50 amps (say) on the 5V rail when nothing else is under load, and 25 amps (say) on the 12V rail when it's similarly all alone. But the 12V and 5V rails together may only be able to deliver, say, 350 watts between them, when they're both under load. Watts equals amps times volts.

In a real PC, all of the power rails will always be under load together.

But you're not testing what the PSU can really do - you're making pretty numbers for the sales brochure!

So test all of your rails alone, get an amperage figure for all of them, multiply that figure by the voltage of the rail it came from (the nominal voltage, not whatever the voltage had sagged to as the PSU pumped electrons through the dessert spoon you'd soldered to the circuit board), then take all of the resulting wattage figures and add 'em up. That's a wrap, folks. Ship it!

In addition the temperature at which most testing is done as I pointed out before
of course since other manufacturers are producing numbers like this, its alot easier to follow suit than to educate the consumer about what your proceedure is to arrive at realistic numbers, so most test the same way, even if they are a reputable supplier
at least that way you can try to compare apples to apples

could you link me to that PSU?
at Fortron Source the only PSU I see in the 500 watt range is an EPS12V
(FSP550-60PLN with minimum load amps at 0.4A for the +3.3V, 3.0A for the +5V)

[Tim_axe]

I can't find the "FSP530-60GNA" at Fortron Source, although NewEgg carries it. Judging from the "60GN" it should be ATX 12V, since the only other 60GN is a "FSP400-60GN(12V)". NewEgg lists it as ATX though... Since I can't be sure if it is ATX or ATX12V, I'll stay away from it.. (NewEgg Link - http://www.newegg.com/app/ViewProductDesc.asp?description=17-104-968&depa=1)

I think I'd like to look at the Antec True Power line then. Adding up the Rails * Amperage I get a number much higher than what it is sold as. So I guess that what it is sold as is some safe continuious max wattage.

Anyways, I can get the Antec True 480 ($83). And even the True 550 ($105) if I need to. Since the 480 delivers 22A which should be enough, my biggest concern is how long the cables are. I am hoping these have long and even thick cables. Otherwise I'll definately need to get some extensions. I'd be appreciative if you could find this out for me, although you've already shown me so much.

Thanks for your help. Thats some scarry insight into how a PSU is rated. I don't even want to put the 450 up to my mobo with just 1 CPU in it to test it for defects. :eek: I hope that everything is good, because I'll probably pass the CPU RMA period waiting for the PSU to arrive when I finally order it. I guess that is better than blowing up everything with that cheap feather weight of a PSU...

[felix88]

i have a that particular Fortron PSU in an Asus A7M266D with 2 x XP1700s running at 2.25GHz. the rails are solid and i have no complaints.

i think it's a great choice.

*edit* also, if you want to save a few bucks, the Sparkle "FSP530-60GNA" is identical, and sells for $5 less.

newegg link (http://www.newegg.com/app/ViewProductDesc.asp?description=17-103-489&depa=1)

Sparkle product page (http://www.sparklepower.com)

as for Antec True Power/True Control PSUs, i can't suggest them. i've had a bad experience with all of their new PSUs. the most recent, the True Control 550 had horrably weak rails and they were far from solid.

[Vertigo Acid]

I can't find the "FSP530-60GNA" at Fortron Source, although NewEgg carries it. Judging from the "60GN" it should be ATX 12V, since the only other 60GN is a "FSP400-60GN(12V)". NewEgg lists it as ATX though... Since I can't be sure if it is ATX or ATX12V, I'll stay away from it.. (NewEgg Link - http://www.newegg.com/app/ViewProductDesc.asp?description=17-104-968&depa=1)


All fortron PSUs sold on newegg are ATX12V (except on 550w EPS12v), as are most all power supplies sold now-adays. No one sells PSUs w/o the P4 connector anymore.

Also, Aopen supplies are FSP, and may be even less expensive, although there aren't any on Newegg ATM

[Tim_axe]

So ATX12V is simply the ATX powersupply with the P4 connector? From my reading I got the impression that the motherboard connector was different between the ATX and ATX12V and EPS. I think the Gigabyte board I'm going to use has a P4 connector. If the ATX12V is compatible with the P4 connector, then I might get the Fortron...

I'm going to read up on the Antec and decide if the rails hold well on average, otherwise I might just go for that Fortron 530. I wouldn't mind saving the money if the Fortron can handle it well.

[Ice Czar]

ATX (http://www.formfactors.org/developer/specs/ATX_ATX12V_PS_1_1.pdf) = 20 pin plug, your Pentium III's ATX connector and PS

ATX12V v1.1 (http://www.formfactors.org/developer/specs/ATX_ATX12V_PS_1_1.pdf) = 20 pin atx connector + 4-pin plug for "Additional 12V" (same pdf as above)

ATX12V v2.0 (http://www.formfactors.org/developer/specs/atx2_2.pdf) = 24 pin atx connector + 4-pin plug for "Additional 12V"

EPS12V (http://www.enhanceusa.com/documents/EPS12V_v1.6.pdf) = Power supply with 24-pin EPS12V connector, plus one 8-pin "additional 12v connector".

SSI (http://www.ssiforum.org/) = Intel spec, which, among other things, defines the "EPS" "enhanced" ATX specification

FormFactors.org (http://www.formfactors.org)

the GA-7DPXDW-P can use either a ATX or ATX12V v1.1 PSU with a 20pin main power connector, there would be nowhere to plugin the "additional 4 pin 12V connector" however

[felix88]

the Fortron has tweakable rails IIRC.

i'd take it over an Antec any day. i guess thats just personal preference.

[Ice Czar]

and just to muddy the water some more :p
Power supplies become increasingly expensive (http://www.theinquirer.net/?article=11279) June 13, 2004

He explained that the later P4 CPUs take their power from a 12 Volt feed and, using the onboard voltage regulators, generate the high current, low-voltages they need to operate (anywhere from ~ 1.6V to around 2.7V). So the first requirement is a PSU that has plenty of power available from the 12V supply. Since the older ATX compatible PSUs didn't supply much current from the 12V section you have to ensure that your new PS delivers enough current (or power in Watts) from the 12V section. That's why using your old P3 ATX PS is a big "no-no".

He then described the history of the post-P3 power supply mess:

The earlier Athlon motherboard manufacturers decided to solve the 12v problem by using an additional 4-pin square connector to get the extra 12V those CPUs required. However many older PSUs didn't provide the 12V 4-pin square connector.

The motherboard makers then wised up and decided that there was nothing magical about a square 4-pin connector, so they put a normal hard disk type socket on the motherboard and provided the 12v power via a standard hard disk (4-pin inline) connector. Problem solved - you may now use your older PSUs provided they supply sufficient 12V current (many did not).

Further confusion came from PSU manufacturers not specifying the capabilities of the PSU in a way that allowed the end user to verify it's 12V power output rating.

In the meantime the ATX spec was saying "use the new 6-pin" inline connector - and very few motherboard makers implemented it.

Just to be sure, some motherboard makers, implemented *both* the hard disk style 4-pin inline connector and the square 4-pin connector. They said "use either or both in any combination you like".

The spec then evolved to the 24-pin main connector. Again, most motherboard manufacturers did not wish to make their customers mad by mandating that they replace their power supplies. This might cause their customers to avoid motherboard upgrades. Some used a "special" 24-pin connector with the extra 4-pin connection blocked off, or colored so that the user could plugin a 20-pin plug into the correct end of the 24-pin socket on the motherboard. Many others simply ignored the 24-pin requirement in the specs. Again - problem solved - use your older PSU.

[Tim_axe]

Judging from the pictures @ Newegg, the motherboard (Gigabyte ga-7dpxdw-p) does have a place for that aditional 4-pin 12-volt connector. This is ATX12V v.1.1 right? And is that image accurate? I noticed that some pictures don't actually match the product 100%...

http://home.steven.murphy.name/cliff/files/misc/photos_newegg_gigabyte_ga-7dpxdw-p.jpg
(Image Copyright Newegg.com, Hosted image on my own server)


I read some reviews, and came across the Vantec 520 "VAN-520A". It supplies 28A on +12v, and sacrafices some +3.3v that I wouldn't use much of anyways to bolster some +5v. It seems to meet my power specs for +12v, and even enough +5v (with +3.3v combined)) if I have to run my CPUs off of +5v. The review I read said it was estimated to cost $150 before it was officially released, but Newegg has it for just under $100. NOW, I am considering this Vantec 520 to be the solution to my search for a PSU. (It does have conversion cables for the 24->20 pin)

I do have one question about it though. Will my Gigabyte "ga-7dpxdw-p" 760MPX motherboard work with the Vantec PSU? According to this review ( http://www.tech-report.com/reviews/2002q3/psus/index.x?pg=4 ) Tyan's Dual Athlon boards (760MPX) are not compatible with it! Why is this? Because of this, I'm worried about compatibility with my motherboard...

[Vertigo Acid]

Tyan used the ATX-GES standard for their AthlonMP boards, which was designed for them, and is what everyone should use except the whole cost thing.

Anyway, i'm running a Vantec Steath 520 on a K7D MP board, and it works great.

AFAIK, all MPX boards use 12v for the CPU

[Ice Czar]

According to this review ( http://www.tech-report.com/reviews/2002q3/psus/index.x?pg=4 ) Tyan's Dual Athlon boards (760MPX) are not compatible with it! Why is this? Because of this, I'm worried about compatibility with my motherboard...

well the Tyan Thunder K7X (S2468GN, S2468UGN) and Thunder K7 (S2462UNG, S2462NG)
use ATXGES (http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/25823.pdf)

edit > Damn Beat me
but i got better linkage :p