extreme PSU calculator and ATI/AMD certified...reliable?

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smoothjk

New Member
I find that using the online extreme PSU calculator--and even going by what ATI certified tells me--gives me low PSU requirements overall. For instance it tells me that if I were to upgrade to a Phenom quad core, 125W, and a HD 4850, I would only need a 378W PSU. ATI tells me that my Antec TP3 550W PSU is good enough to handle 4850s in Crossfire (or at least two 4830s in Crossfire).

Yet, if I were to ask people on these boards, they would definitely tell me I need to upgrade my PSU. Why are the values so promising and low online? Are they just assuming you'll never use your system to full load or something?
 
I check the wattage needed on newegg on the specs page of the given part

Are you already upgrading? I just got my 9600 gt and 6000+ 3 weeks ago and dont think ill upgrade for a year or so.
 
I don't know when I'll upgrade exactly...it's more or less dictated by the next price drops. =P But I want to know that I'll have options that are realistic, cost-wise. Knowing me and my impatience, if a good Phenom or the ATI cards dropped in price, I'd probably buy it very quickly.
 
Look at it this way. If you knew it only took exactly 1 gallon of gas to get somewhere in a car. Would you leave with exactly 2 gallon of gas to get there and back, thats all. There is nothing wrong at all giving your current P/S a go with it and see if it can pull it, if not 99% of the time all that will happed is restarts. But if your building a new system I would not suggest just getting the Exactly amount of Amps. and Watts you need.
 
I see what you're saying. It's just that even if I'm generous with my estimates for future upgrades, the PSU calculator will tell me I need something like a 460W PSU, so I'm wondering if my 550W one has enough wiggle room. If I asked real-life people instead of relying on the calculator, I know people would say to get a new PSU.

And if I'm not mistaken, the online PSU calculator doesn't say "minimum required," but rather, "recommended."

I'm just trying to figure out why there's such a discrepancy between what people say/think, and what online sites tell you. Maybe ATI tells me I can do Crossfire because they don't want to lose a potential customer from buying two of their cards...so they put out a low requirement so more people will take the dive.
 
the best way to calculate how much you will actually need is throwing a voltmeter up to 12v+ and seeing how much wattage the entire system pulls. also another thing to consider is how the PSU is rated. if it's rated at 550w continuous power then you should be okay, but if it's rated 550w max then there may be some issues. personally i would get at least a 700w PSU to be on the safe side, go with Seasonic or PCP&C for clean reliable power.
 
http://www.antec.com/usa/productDetails.php?lan=us&id=23550

According to that, it's continuous power, not max: "Accurate power rating allows TruePower Trio to deliver its full rated power, 24 hours a day rated at 50ºC".

ATI's site (http://game.amd.com/us-en/crossfirex_components.aspx?p=3#ATI Radeon™ HD 4850) lists my PSU as certified for 4850s in Crossfire, which I find surprising...that is, if I'm reading the chart properly. Not sure what the PCIe 2x3 and 2x4 columns mean.

At the very least, my PSU can handle a Phenom and a single 4850. once I decide to go Crossfire, maybe I'll upgrade then. =)
 
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Just for fun, I calculated to see what my power requirements would be if I added a 125W Phenom, overclocked it, had two 4850s in Crossfire, added an extra HD, added a Blu-Ray drive, and had everything running at 100% peak load. It then recommended me a 548W PSU. =)

I think as long as my 550W one is a quality unit and delivers consistent power--which I think it does--I might leave it alone for a few years. Realistically, I'm not going to be adding all those components and then running them at the same time, full load.

I'll upgrade only if I start cutting it close...money is scarce, even with the new job and pay increasing coming up. =P
 
smoothjk said:
Just for fun, I calculated to see what my power requirements would be if I added a 125W Phenom, overclocked it, had two 4850s in Crossfire, added an extra HD, added a Blu-Ray drive, and had everything running at 100% peak load. It then recommended me a 548W PSU. =)

I think as long as my 550W one is a quality unit and delivers consistent power--which I think it does--I might leave it alone for a few years. Realistically, I'm not going to be adding all those components and then running them at the same time, full load.

I'll upgrade only if I start cutting it close...money is scarce, even with the new job and pay increasing coming up. =P
Click to expand...

you don't want your PSU running at peak power all the time. if you throw a load like that on a PSU 24/7 you're going to pop capacitors. i've known of way too many antecs that have died recently to trust my velociraptors & GTX to them, i wouldn't run crossfire with that PSU. i wish antec was still selling PSU's with the same quality that they had 3-4 years ago, it seems they are relying on their former reputation to sell cheap rebranded chinese psu's. either way, what you do with your money is your choice.
 
Don't get me wrong, when the time comes to run two GPUs in Crossfire, I'm going to upgrade for sure.

It's just that if my PSU can SUPPOSEDLY run Crossfire and some components I don't even have, then running a single card seems like a relatively safe bet. That's all.
 
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