Getting max/min watts and amps

The manufacturers just overstate what size power supply is actually needed for one thing based on a fully loaded maxed out system which you won't have.  Your system with the 375W unit has enough watts and amps for this card.  Your concern with amps is how many you have on your two +12V rails and how many watts on those rails. The sticker information on the side of your power supply will sometimes indicate how many watts are running on the two +12Vs.  Whatever the wattage is you would divide it by 12 to get the number of amps on those rails and not just add 18 + 18 and get 36.  I think this power has 30 amps, but I'm not sure.  Therefore, it would show 360 watts under the two +12V rails.  The amp requirement stated by the manufacturer is what you need for the entire system not just for the card itself just like how they state power supply requirements.  The card would never need 400 watts or 30 amps by itself as you know.    

It does not matter what type memory the video card has whether it is DDR, DDR2, DDR3 or DDR5.  This does not need to be the same as your system ram which might be DDR2.  

Here is a chart showing the power consumption as tested under load such as gaming for the entire system.  It comes out to 175 watts.  Personally, I don't care for a passively cooled video card such as you linked because they tend to run hotter than one that is cooled by a fan.  However, I'll leave this choice up to you.  

Thanks for a great reply!

Your system with the 375W unit has enough watts and amps for this card.

This is a sentence that I've asked for in many places, but never got.

I will admit, I've read  the lines about amps and rails four times now.
And I'm not fully sure what you mean - mostly because I do not know what a "rail" is.

Anyway

I've got a number here, from a "not-very-reliable" source, a foreign sales-page, translated with google translate, about my motherboard:
"Mercado Libre" - Dell Dimension 9150 Model: yc523/fj030

According to this, if I understand it right, this motherboard cannot provide more than 150W to the PCIe-slot.
I questioned this, and dell support told me by phone "This might be true"

So, as the chart shows that the Radeon HD5570 will use 175W as max - it won't work?
Or have I just done "too much" research and got something (very) wrong? ;)

Also, the reason for choosing passive cooling, is that I can be sure that I won't have to plug anything from the PSU to the video card, as Dell support told me that this might be a problem (Wrong connectors)

Thanks for the first explanaiton - but here I bomb you with more questions :emotion-15: ;)

//Mattias

I'm following this post as well because I have the same type of questions: for the card I'm looking at for a Dell XPS 8100 the EVGA site says 450W are required....I hadn't even considered that the motherboard might not send sufficient power.

dg

Pretty much wrong.  The HD 5570 will only use 42.7 watts under load and 9.7 watts at idle.  The 175 watts is for the entire system including the video card.  This card does not require additional power from the power supply and it has no additional connectors on it to supply that power.  No HD 5570 requires the additional power.  The PCIe slot provides 75 watts.  Each additional 6-pin connection if needed provides another 75 watts.  However, you don't need it since the card only uses 42.7 watts at most.  Having passive cooling or fan cooling has nothing to do with needing additional power from the PSU.  Passive cooling is just sometimes used only to have a silent card on lower-end video cards that may not generate a lot of heat like the higher-end cards do.  Fan noise never bothered me, but for some others they just want a system to be as quiet as possible.   I have 7 fans running in my computer and it does not bother me at all.  Heat has definitely ended the life of some of my components prematurely in the past such as power supplies and motherboards so I know to keep things as cool as possible if you subject your system to the stress of gaming.  

Now that's great info, and it makes sense.

Thanks for all the help JMICHAEL!

Hm, as for noice/heat.

This computer sometimes stands on and works on something (not graphical/animation) during nights. As you seem to have experience with fans. If I buy a card with a fan, will it always be on, or just when "gaming"? I mean without overclocking etc.

Thanks again

//M

The fan will always be on because it needs to keep the GPU cool, but will run at a low rpm at idle or not gaming if it is a variable fan.  I don't even hear mine at idle but use software to create a fan profile to increase its speed when gaming.  The default speed of fans vary depending on the card.  Mine idles at 40% and really does not increase until it reaches 70C which is why I created the profile for this one.  My previous card would automatically increase fan speed when gaming so they are different and do have different noise levels so it is worth looking into if noise is a concern as I do not like a noisy cards at idle which is how it is most of the time and I have had some older ones that were.  I have heard of cards that run at 100% all the time because the fan is not variable so to me it is worth a call to the manufacturer if you are unsure just to verify before you make a purchase.