Motherboards, Processors and Recommended Power Supplies?

powerlord asks: "I am in the process of putting together an Athlon based system. While opening up the Motherboard (FIC-SD11) and processor boxes, I was shocked to find a list of 'Recomended Power Suplies ... void of warranty...'. I always assumed that if it was an ATX power supply it should be fine. Is there something special about an FIC and Athlon that make them more 'touchy' than other motherboards and processors? Is this just a legal disclaimer to limit themselves from being sued if the product is used in a way they didn't intend (running from a car adapter)? Is this the start of a new disturbing trend... buy what we've tested with or we won't honor our warranties? "

This is a pet peeve of mine ...

[Anonymous Coward]

Power supplies are supposed to be beefy. This avoids a whole host of problems. I have seen going to a better power supply get rid of "gremlins" with disks, RAM, CPUs, and any kind of writing media (CD-Rs, tape). Any power supply that costs less than $150 for 300 watts is suspect. For a cheap low power (i.e., WinChip 200) IDE box, 225 watts from a small box is OK, if not loaded, and on a big UPS. For anything else, you need a decent supply. Trust me -- your components will run cooler, last longer, and you will have far fewer errors, let alone lock-ups.

These don't have to be new, either -- try scavenging the auctions or places where they break up unsold boxes and get a used power supply -- the good ones are built to last and do so.

Needs a heavy duty power supply

[jeremyphillips]

The Athlon and it's motherboard are picky about the voltage going to them. The Athlon is a power hungry beast, and when it's load is dropped on most power supplies, the voltage tends to sag. So to save space, money, and everything else, they offloaded alot of the voltage regulation off the motherboard and put that responsibility onto the powersupply. Hold a Athlon-approved powersupply in one hand and a regular in the other. You can feel the difference in the weight. The Athlon approved has got beefier capacitors, and it's pretty rock solid on holding the 5 and 3.3 volt lines within a tight spec while heavily loaded. The power supplies aren't the cheapest things either; they're running around $45 here in San Diego, CA.

Jeremy

Not that I know of

[Paolo]

I've used a fair number of FIC motherboards in the past with several different power supplies and it should not matter. I think their reasoning on recommending power supplies is either because of special interest (paid to do so) or just out of courtesy. I would use a 250-300 watt power supply for an Athlon board, simply because the Athlon (along with the PIII) draws a lot of power, and chances are you'll add lots of drives, etc.

Can't say about ATX

[andrewmuck]

But I built an AT supply for a car MP3 player and found that its 100W was a lot more steady than a generic 200W supply. I think the trick is to just over design for what you need so there is a safety margin. Safety margins are cut in comercial products to boost profit margins, the wattage specified seems to be the extreem edge of what they can supply not what they are designed for.

I have yet to build an ATX supply so I am unaware of how critical sequencing is (someone please mail me on that!) but the standby and power-up down should not be hard. Personally I think the standby is just a waste of power (esp. in a car), just optimise your startup scripts and keep most of the FS read-only and the rest mounted sync.

cya, Andrew...

Re:Not that I know of

[slntnsnty]

We have seen problems with the FIC boards and Athlons > 600Mhz... They draw a lot of current apparently, we had a board that would not even power up without a 300W power supply.

Re:Needs a heavy duty power supply

[Bakerman]

Agreed. I have an extremely powerhungry system, a Dual 300MHz PII (Klamath core) with several 7200 rpm drives and a 5" cooling fan connected to the 5 volt line. The processors alone use almost 80 watts. My powersupply isn't quite up to it, so when I load the computer (move some windows around in X, for example), I can hear the fan speed dropping (since the PIIs manage to lower the voltage on the 5 volt line). It has caused no problems so far but it makes me a bit uneasy. This is a standard Enlight miditower case and power supply.

Bottom line, pick a power supply that you know can handle the load.

/Erik

Re:DC Power supplies?

[andrewmuck]

There are plenty around they just cost :( you can get some as kits, or there is an open design on my site [xoom.com] and you can build your own. Look around the mp3car webring, you will prolly see whats available.

cya, Andrew...

Ars Technica Has an article on why

[janic]

Ars went though this a while back at http://arstechnica.com/reviews/4q99/athlonmobo/sho otem-2.html

I will concur with most of their findings. We sell alot of the GVC boards around here and even they are picky about the power supply sometimes. IMO, I don't think that it's payola or anything like that, I just think that the newer, faster mother boards require a cleaner, more powerful P/S.

John.

(Snarfed the appropo. bits from the article below.)
>When I first got this board and plugged her in I was using a "PowerMan"
>FSP300-60GI to deliver the juice. I was able to get the board to boot up,
>but ye olde Win98 install would either BSOD or not boot! After working all
>the mojo I know on the 'board, I decided that I just got a flukey mobo
>that didn't work. When I got the second 'board in and had the same
>problems, I knew something was fruity.
>
>Looking through my materials once again, I noticed a slip of paper
>advertising the "recommended power supplies" for this board. Well, I
>mean, what does "recommended" mean? For me, it meant it was a no-go
>with my current setup. I called up and ordered a Sparkle Power
>FSP300-60GT from The Chip Merchant, and after dropping that supply into
>the box, lo and behold, the machine booted up with no further problems.
>This tells us to double-check the power supply in our machine before
>buying this board, or at least expect to purchase another supply with the
>motherboard. BTW, the PowerMan supply did work with the BCMGVC
>QS-750, so I know that it's a FIC-centric issue. And before you go dissin'
>the PowerMan power supply, chew on this: it's an OEM from Sparkle, one
>of the most well-respected suppliers in the industry, who made the other
>power supply that worked with this mobo. Can you say FICkle? Not to
>worry, though: you can check to see if your power supply is on the list.
>Here's something odd: the list is maintained by AMD!

Athlon

[Mr.Mustard]

My understanding of this issue is that the Athlon needs a highly consistant power supply and the recommended supplies are the ones that have been tested and work. This is documented on amd's homepage in the athlon processor section under "Recommended Power Supplies [amd.com]". Or, to quote from that page:

To ensure reliable operation of AMD Athlon(TM) Processor-based systems, an AMD-recommended 250W or larger ATX 2.01 power supply is required for the majority of system configurations. Recommendations are based on the ability of a supply to provide the power sequencing and current requirements of AMD Athlon systems. The current supplied on the +5VDC power rail as well as the combined current supplied by the +5-VDC and +3.3-VDC power rails has been tested on the supplies listed below.

When selecting a power supply for your system, please refer to the following list of power supplies that have been evaluated and are recommended by AMD for use with AMD Athlon processors. The following power supplies are recommended for their capability to supply appropriate power on both the +5-VDC and +3.3-VDC power rails. In addition, this list is not intended to be a comprehensive listing of all power supplies that support AMD Athlon processors.