Sufficient Power Supply?

I'm condsidering an Nvidia 7600 GS AGP.

So far I've seen conflicting system requirements for a minimum power supply rating ot either 300W,,, or 400W.

Can anyone verify what the minimum requirement actually is? I can't find it on the Nvidia site or any where else for that matter. My PC has a 300W supply.

Thanks in advance.

Well, it really depends on what all you have running in your system, but I generally don't put anything smaller than 400W in any "heavy duty" PC I make. IE, gamer rigs, workstations, etc. Anything with a powerful processor, lots of memory, lots of motherboard features, lots of drives, a powerful graphics card (or two!), I wouldn't trust to run smoothly with anything less than 400W.

One thing is for sure: you can't go wrong with more power.

Talarus is right, the more the better. 300W is pushing the minimum limit for a current midrange PC. Especially if you have multiple optical or hard disk drives, you're going to want something more. I'd go with at least 400 to be safe and 500 if you plan to add anything to the system down the road. Better to pay $20 extra for the bigger supply now than have to pay $100 for a whole new one in 6 months.

But to answer your REAL question, most reviews I find say 300W minimum. If you're buying it from a retail store, check out the requirements on the box to be sure. To play it safe, I'd suggest upgrading your power supply at the same time.

I was just checking TigerDirect and was pleasanlty surprised with the prices for a 500W supply.

My only question is which one to get? Of course I'll go and check what type of connectors I have but what about how it attaches to the case? They really don't go inti those kind of specifications.

The PC I have is an older Pentium IV, 1 mg ram, AGP graphics slot, which I'm going to use ONLY for SL. No other add ons, no special drives or accessories. I just wanted to try and upgrade this machine without spending too much on hardware.

My ultimate goal is to build an SLI Nvidia PC for my SL addiction! But that will have to wait for now.

To be perfectly honest, I only ever use Coolmax but that's just personal preference - I've always been happy with their stuff. For other manufacturers I usually depend on the reviews at cnet.com or whatever other buyers on the site are saying. Of course, the old rule of thumb about "you get what you pay for" always applies, so I would stay away from the $9.99 model.

As far as what would fit your case, I would be surprised if you have anything other than an ATX case, so any ATX power supply should work. If you're worried about it just post your PC brand and model number and either I or someone else should be able to tell you what you need.

I was originally going to go with the "Coolmax CX-550B". Then I saw that it didn't have the Nvidia 'SLI Ready' certification. My plan is to use this power supply in the new PC (when ever I'm able to get the additional finances together to build it).

I was considering the "Ultra X2 550 watt ATX". I has the SLI cert and also have modular wires. ( Not that I think that os such a big deal. Supposedly aids in cooling because you only use the wires needed fro installed components.) Is the SLI cert. really advisible? I can get the Coolmax for almost $40.00 less.

My PC is an AOpen mini tower. I don't have the extact model number handy as I am at work right now. I can post it later.

Thanks for all of the answers and support. This forum has proved invaluable regarding the associated hardware to make SL enjoyable!!!!

Keep in mind just cause it says 500watt doesnt mean a 400watt can be better, look at their +12volt amp, if you see lower then 20 dont get it, most come with 25-35+ amp now.

Also get least a ATX 2.2 standard psu -.o

+3.3v/+5v never had issues with, its the +12volt thats for vidcard/motherboard thats usually get issues.

Choosing a power supply is becoming a non-trivial task. Wattage is pretty much useless as a measure. We've got power supplies with 2 and even 3 12V rails. And sometimes they beef up the 5V rail way more than is needed to inflate the overall wattage.

I've got a question and then I just want to relate the problems that I've been having.

Question: if you have a PCI-E graphics card with the 6-pin 12V connector on it, does the card draw its power completely from that connector or does it also draw power from the mobo?

Recent Events

So recently, I upgraded my vid card from an nVidia G-FORCE 6600GT to an ATI X1900XT. The X1900 is an awesome card, but I'm still working through issues with the power supply.

My original power supply was rated 500W, and had worked for over a year with the 6600. But it went up in flames within hours of installing the X1900. There was a loud pop and smoke came out the back. LOL. Luckily, there didn't seem to be any damage to the rest of the computer. It was a $30 power supply that came with an off-brand PC.

So, then I got an Antec Neo HE 550W (http://www.newegg.com/Product/Product.asp?Item=N82E16817103941). It has three 12V 18A rails One goes into the mobo and another into the PCI-E graphics card (the X1900). At first, this seemed fine, but recently I've been having significant problems with it turning off on me unexpectedly. Presumeably this is because it is getting overloaded and the circuit protection is kicking in to shut it down before it blows like my first PSU. Sometimes now, it won't even turn on. I press the Reset button and it starts to power up, but then it turns off. I have to turn it off and try again in a few seconds. Also, when I start doing something graphically intense, it shuts off.

I'm still not sure if it's a problem with my Neo HE or if it's still underpowered for my setup.

But I figured I'd try another one to see if it's better, so this time I bought an APEVIA ICEBERG ATX-IB680W (http://www.newegg.com/Product/Product.asp?Item=N82E16817148028). This has two 12V rails (24A and 22A). This one appeared to be DOA and I've just sent it back for a replacement.

Needless to say, it's been frustrating.

Hardware:

Pentium 4 3.6 GHz (2 GB RAM)
ATI X1900XT 256MB PCI-E Video Card
hardrive and two DVD drives

Good Lord this is getting confusing!!!! lol.

Shack. I hope you get an answer to your question. I'd also like to know the solution to your problem!

I guess I'll have to do some more research into the amperage stats before I make the leap for a new Power supply. Again,,, thanks for the responces! At least I'll be as informed as possible to make the best selection.

OK,,, here's the spec's of the two power supplies I'm considering. One is SLI certified and the other isn't. Please feel free to comment.

(1) COOL MAX 550Watt

+3.3V +5V +12V +12V -12V +5VSB
30A 50A 18A 18A 2.5A


(2) ULTRA 550 Watt "SLI Certified"

+3.3V +5V +12V +12V -12V +5VSB
25A 30A 17A 18A 0.8A 2.5A

Well, there you have it. The Coolmax seems to have the higher specs but the Ultra has thr SLI certification. Your opinions please!!!

With those stats alone, I would go with the CoolMax. A PSU might not have a "SLI Certified" sticker for a number of reasons; such as not having two PCI-E power connectors, or the manufacturer just not applying to have that model certified by Nvidia.

My personal favs for PSUs are Antec and PC Power and Cooling. Antecs I've found are very reliable and are at good prices for the features and build quality. PC Power and Cooling PSUs can be very expensive, but if you are building a high-end computer that needs the most stable and most reliable PSU, they can't be beat.

Considering your needs, it looks like the Cool Max is the way to go. Even though the other PSU is SLI certified, the 17A 12V rail makes me worry.

Thanks Ketra,

I found an upgraded CoolMax unit for $20.00 more with even higher ratings on the +12V side, (35A). This PS should do the trick in the present PC and hopefully the next.

Carolyn, I posted this up in the other forum....

What I got in mine was a 485w PS Enermax, which was the wattage the guy recommended to handle the additional needs of the graphics card, two hard drives, and a fully loaded set of CD/DVD/Card Reader, etc..

http://www.newegg.com/Product/Produ...N82E16817194009

I went with this power supply because it was suggested to be both quiet and enery efficient.

Thank you Isablan!!!

So many possibilities to check out!!!

overkill 1 (dualcore/sli)
< 720watt > +12v (1-2-3) cpu 28 | gpu 28/30 amp

overkill 2 (quad core/quad gpu)
< 1000watt > +12v (1-2-3-4-5) cpu 17/17| gpu/17/17/17 amp

o.O the new 8800cards are way...to hungry on power, reminds me of first gen 7x00 nvidia cards.

I always recommend anyone who buy a new pc case/pc replace the psu , its not very quiet compared to the one you can buy, well some namebrand pc's are ok (but just about enough to barly run it tho -.- so not so good when its upgrade time)

My Antec case came with the Neo HE 430, and the problem of turning off was NOT because it was overloaded. Exactly the opposite. There wasn't *enough* power draw on each rail to keep the PSU functioning properly.

I had to switch around my power cables until there was at least 1amp draw on each rail, and that cured the problem.

Interesting! Got my attention.

So how did you do this?

On the NeoHE 550, there are five modular outlets in which you can plug cables. Initially, I had fans and drives going into the first 2 and the video card going into the fifth.

I must admit the whole rail thing has me a little bit confused. I know there are three 12V rails, then there are other voltages such as +3.3V and +5V. Actually, looking at the 430, it seems like there are two +5V rails maybe.

Well, just looking at the 12V rails. I know that one goes to the mobo and another to the video card, but I'm not sure what to connect the 3rd one to. LOL

I have the NeoHE 550, and its been working fine for just over a year.

I don't know if the two power supplies map in the same way, but let's assume that they do. The notes I read on NewEgg customer reviews were very helpful:

http://www.newegg.com/Product/CustRatingReview.asp?DEPA=0&Type=&Item=N82E16811129166&SortField=0&SummaryType=ALL&Pagesize=&=0&=10&Page=7

>> The Antec Neo HE PSU included in this case has to have a minimum current draw on each 12V rail or it just turns off and will seem like a defective PSU. So if you're computer is not turning on , just add more stuff in your case to consume power and its best to put some power consuming device attached to the first and last slot. You need a minimum of 1 amp on each rail, the mobo is rail 1, slots 1-3 (left to right looking straight at them) are on rail 2, and slots 4-5 are on rail 3. Then when you try to power on the computer, it works! Hopefully it will stay that way.<<

Let me know if this works for you.

Getting back to Carolyn's original question: I'm running a PNY 7600GT (256MB) on a 300W system , and it works just fine! ( not to mention doing 10x the frame rate, with *everything* maxed-out, compared to the original on-board chipset).

Regan, thanks so much for posting this!

It didn't solve my problem, but it was tremendously helpful to realize what's really going on. After reading your post, I did a search and found a thread on silentpcreview that talks about my issue at length.

http://www.silentpcreview.com/forums/viewtopic.php?t=27863

and I also pulled up the full specs on the Antec Neo HE 550. From that you can see that it has a minimum load requirement of 1A on each of the three 12V rails.

But going through the silentpcreview thread, the issue seems fairly complicated. Some people have been able to distribute the load and get it working. Others have added a resistor to create artificial load and get it working.

There also seems to be two parts to the problem. One is the failure to start and the other is turning off under load. I'm actually experiencing both, but the failure under load is what is really killing me. So far, the only solution that I've seen reported for failing under load is to replace the PSU through the manufacturer.

Failure to start appears to be an incompatibility with some motherboards, although I don't have the motherboard that has been most affected. It's unclear if the failure under load is a manifestation of the same problem or if it is separate.

In any event, it's really helpful to have this information. Once I can get another PSU that works, I'll pursue replacement with Antec.

Thanks so much for your help!

You're welcome!