EggXpert

I'm saving my pennies for a Radeon HD 4870 and a 1680x1050 monitor. Right now I have a 7900GS (Great card, OCed to 590/824 rock solid) and an old IBM G78 CRT monitor. I'm not sure of the exact power requirements of the 4870, but my system (See my sig) doesn't draw too much power, and my Antec TruePwer Trio 430W has been good so far. Do I need a new PSU? If not, that's good. If I'm going to be stressing my PSU, I'd like to get a new one so I can make sure my PSU doesn't die on me, since I know that can be a nasty thing. If I need a new PSU, I'm looking at the:

PCP&C Silencer 610W or the

Corsair 650W

I know they are both good, and might be overkill, but having a bit of headroom is never bad, right?

P.S. Does the 4870 need both of the PCI-E power connectors? Or will it run on just one? Granted, with either PSU I'll have both of the connectors, so I'm good, just a bit curious, though. 

Inplabth:

I'm saving my pennies for a Radeon HD 4870 and a 1680x1050 monitor. Right now I have a 7900GS (Great card, OCed to 590/824 rock solid) and an old IBM G78 CRT monitor. I'm not sure of the exact power requirements of the 4870, but my system (See my sig) doesn't draw too much power, and my Antec TruePwer Trio 430W has been good so far. Do I need a new PSU? If not, that's good. If I'm going to be stressing my PSU, I'd like to get a new one so I can make sure my PSU doesn't die on me, since I know that can be a nasty thing. If I need a new PSU, I'm looking at the:

PCP&C Silencer 610W or the

Corsair 650W

 

I know they are both good, and might be overkill, but having a bit of headroom is never bad, right?

well, if we consider your computer with the CPU running at stock speed, it draws about 350watts at full load(the Radeon 4870 video card draws 150watts at full load).  So, your computer with the new graphics card would likely work fine on that power supply.  Also, the Antec Earthwatts power supplies are good-quality Seasonic made units.  If you were to give it a load more than it can take, it has over-power protection built in, so it will just safely shut off(many cheap power supplies do not have this). 

However, I don't know how much extra power that CPU draws when overclocked.  So, getting a higher wattage power supply would be a good idea. It'll give you more headroom for upgrades and overclocking. 

While the two power supplies you picked up there are both very good, you can certainly get a high quality power supply for cheaper than that.  The OCZ StealthXStream 600watt power supply is currently on sale for only $54 w/ free shipping at newegg.  According to a review of that power supply at HardwareSecrets.com, that 600watt model is actually capable of putting out about 728watts of power, amazingly enough. And, it can provide 52 amps of 12v power.  So, that power supply should be plenty for your computer. 

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Well, my CPU is still on stock voltages at 3.0 ghz, so it's not really drawing any extra power.

EDIT: Well, according to the ExtremeTech PSU calculator, my computer is using 211W right now, and it would be 309W with a 4870. 

Inplabth:

Well, my CPU is still on stock voltages at 3.0 ghz, so it's not really drawing any extra power.

 

EDIT: Well, according to the ExtremeTech PSU calculator, my computer is using 211W right now, and it would be 309W with a 4870. 

that's around what I'd estimate.  I put a little extra in my calculations just to be sure that the power supply will cover it, and because I don't know, say, how many case fans you're using, or how many PCI cards you have. 

Hoghauler: is there any reason that you put in 35% for the capacitor aging?  Do you know what amount of running time corresponds to that percentage of aging? 

Just to note, when I do my power estimations, I generally use one hard drive and one optical drive for the base wattage.  If you have more of those drives(or are planning to add more of those drives), just add in 25watts for each additional optical drive, and 10watts for each additional hard drive. 

That OCZ StealthXStream 600watt power supply selling for $54 that I linked above is a good choice, you may want to get that before the sale expires. 

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HOGHAULER:

No I do not know precisely what amount of running time 35% aging is but going by the parts he has I would estimate the build to be about 8-12 months old and not knowing how he runs his computer I would rather over estimate than under estimate it to be on the safe side plus adding the possibility of high end gaming to this neither I nor you know how good ashape his PSU is in.

well, just throwing an arbitrary percentage in isn't a good way to get an accurate answer.  35% could be one year of usage, or ten years.  You can throw in a different percentage there, and get a vastly different answer(for example, put in 50% aging and you get 560watts).  So, unless you can at least have some factual basis upon which to base the number you're putting in there, you should just leave that out.  For all you know 35% might correspond to ten years of usage. 

 Let's look at some real world testing of an older Antec power supply, this one even with cheap, and known low quality Fuhjyyu capacitors.  From JonnyGuru.com:

JonnyGuru.com:

The dreaded "F" word, Fuhjyyu caps populate the secondary side. Before you go running around the room with your arms waving over your head and screaming "OMG!" bear in mind that from personal experience I've had two CWT based Antecs with the Fuhjyyu caps in them that lasted for over three years of 24/7 usage. In fact, out of curiosity I popped my True Blue 480 on the load tester and cranked it up to its full rated wattage and it held up perfectly fine with good stability and held its rated 3% voltage per rail. I've always been an advocate of good case cooling and this just reinforces that if you don't overheat these caps you're fine as far as reliability goes. That said, I'd avoid using this PSU if you're cooling impaired and you're relying on the PSU for a major portion of your PC cooling.

So, as you can see, even with low-quality capacitors, an old antec power supply has lasted for over 3 years of 24/7 usage, and is still able to put out it's full rated wattage.   So, apparently, you should not be putting any of that calculator's "capacitor aging" into the calculation. 

HOGHAULER:

his specs told us what fans he has plus the CPU HTSK&FAN he installed.

You are correct.  So, it would seem that my calculation overestimated the power a bit.  The number that he got from the wattage calculator seems to be pretty accurate. 

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Inplabth:

Well, guys, my budget is a bit tighter than before and I've decided to go with a 4850 and a 19" monitor. Does anybody know what the amperage requirement is on the 4850? I ran my system through the PSU calculator and I should be able to handle a 4850, but the calculator doesn't give amperage requirements.

well, that should be all right then.  Your power requirements will be around 300watts or so with that card(or perhaps a bit less), which is certainly within the capabilities of your power supply. 

Also, your power supply, the Antec TruePower Trio, actually only has a single 12v rail.  It says it has three 12v rails on the packaging, but according to testing, it actually only has a single 32amp 12v rail.  This is a good thing, because you will not have to worry about balancing this load across the rails, which becomes harder to do when you come closer to the limits of the power supply. 

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