300w PSU - help!

[ojpd]

Hi everybody.

Ok so here it goes.. I am building a PC and I have this very simple question but first here are the parts I already bought.

Athlon 64 3500+ Processor "PIB"
EPoX 9NDA3J Socket 939 nForce 3 Ultra
Inno3D 6800 @ 16x6 @ 400/800
2 x 512 MB Geil
80 GB Western Digital HDD SATA-150
Asus CRW-5224A
Mars Orbit ATX Case

The shop included an Antec 300w PSU but I am having doubts that it can run my system? I tried this site:


http://www.jscustompcs.com/power_supply/

As some sort of reference but I need expert opinions. Knowing that I only have 1 optical drive and 1 HD and no floppy I have been thinking that it might be enough. Would a 300w PSU be enough for the specs I mentioned? Or do I really need to get a stronger PSU?

And oh by the way.. This is my first post!!

[Rondog]

Should be big enough. I run an IDE HDD, a SATA HDD, a DVD burner, a A64 3200+, 1gb of RAM and a 9800 Pro on a 350W Enlight PSU.

Hope this helps.

[ojpd]

Actually it helps a lot Rondog. Im not planning on buying and attaching anything else. But a follow up question if you dont mind. What if I add a side case fan? Would it still be ok?

[Favu]

Welcome to AOA ojpd!

You should be able to run your system and an extra case fan OK from a 300Watt PSU, provided it is of good quality, however, I would recommend going for something with more juice - the 6800 are quite power-hungry AIUI. If you are planning on overclocking I would recomend at least a 450Watt PSU for that system

[ojpd]

That's what I thought too. Been googling around and looking at forums.. People keep saying that the +12v rail should not be less than 20a on a 3500+ with a hungy gpu and some fans..

[Pitch]

Favu.. do you sleep? It's 3AM.. Wait.. oh crap.

[SteveI]

Don't worry too much about total wattage. The quality of the PSU is much more important. There are many 450w - 500w PSUs that are absolute garbage. Your Antec should be up to the task. Don't worry about it unless you experience power fluctuation and instability.

EDIT: BTW, I'm running a 300w PSU on a system with a venice 3000+, oc'd to 2.45ghz, 1gig dual mem, and X700 without a hitch. I even have a 200w PSU w/ a tbred1700+ oc'd to 2.3ghz. Both systems run 24/7 folding.

[ojpd]

Originally Posted by SteveI

Don't worry too much about total wattage. The quality of the PSU is much more important. There are many 450w - 500w PSUs that are absolute garbage. Your Antec should be up to the task. Don't worry about it unless you experience power fluctuation and instability.

EDIT: BTW, I'm running a 300w PSU on a system with a venice 3000+, oc'd to 2.45ghz, 1gig dual mem, and X700 without a hitch. I even have a 200w PSU w/ a tbred1700+ oc'd to 2.3ghz. Both systems run 24/7 folding.

Thanks for the info. I tried running it with my Antec everything seems fine. I have been playing oblivion for almost 15 hours now. thanks again.

[dsio]

If you are using an Antec SL300S model 300W PSU, you are living on a knife edge. The +12V rail is what the 6800s are heavy on, while ATI cards are heavier on the +5V rail, so the X700 should be happier than an Nvidia card.

I don't know if Antec has a quality 300W model, but that SL300S is not going to handle a 6800 at stock for long, let alone one at 16/6 and overclocked.

Check what model it is if possible.

[ojpd]

Right you are on this particular PSU. Recently kept getting random restarts on more heavy scenes while running Oblivion. Swapped it just this AM though and I'm glad to say I am finally over this PSU dilemma. Thanks guys.

[dsio]

The SL300S has been responsible for many destroyed 6800s. Its always best to air on the side of caution when it comes to things like video cards.

Some genius around here sold a bunch of them in gaming machines with 6800NUs to a net cafe near here, and the guy who handled the refitting of those machines lans with me.

The 6800 voltage regulators are happy to have an overvolt on the +12V and on anything for that matter.

When the voltage regulation circuit is <severely> overvolted, and I mean by a lot, or if it is browning out, it cuts out as a safety measure.

Glad to hear you are getting another one. 350W on a high quality unit is what I would call absolute minimum for a 16 pipe 6800 card at stock, safely. 400W high quality or better would definately make me sleep better at night, but it has to be a good quality unit. Antec are not bad my any measure, but are not in the same class as others.

Best of luck mate.

[SteveI]

@dsio - I wasn't aware of issues with the sl300s... good catch.

@ojpd - glad you got it sorted out, even with my help. BTW, what psu did you get?

[ojpd]

This forum rocks. I learned quite a lot about PSUs just by posting here. Well I went to all the shops my car's gas could take me to and the only name brand I could find that is being sold here is Enermax so I took the plunge. I may not be able to buy my labrador some decent dog food for the next week and a half but for sure my pc is safe and futurewise hehe I'm sure he'll understand hehehe

Enermax Liberty EL500AWT - This is the best I could come up with it has 22a on each of the 2 +12v rails.

[dsio]

Oh mate, Enermax is absolutely brilliant. And the liberty range, is a top notch piece of equipment.

22A on each +12V rail, and 500W total on a very high quality unit like that is great.

Think about the fact that this has 22A on EACH +12V rail, while that SL300S had a single 15A combined +12V rail.

3 times the +12V current rating. And when Enermax say 22A, they mean 22A.

Great choice.