Concern about a power supplies wattage

[AmpLighter]

We're in the market for a new computer, but I have a concern after searching the HP site. It would seem that designated pc's show video cards like the Raedon R7 require a power supply of 350 watts or better. The Pavilion 570 xXxX with the Raedon R7 has a power supply of 300 watts. How would can this lesser power supply handle a video card that requires a power supply of 350 watts or greater to function properly?

Please explain to me why several of the HP systems have lesser  power supplies yet are suppose to support dedicated video cards.

[erico]

You posted this in the notebook section. I can move it for you.

[AmpLighter]

Thanks for moving the topic  as I'm currently using a very small tablet to access this page & the old eyes aren't able to see the entire page.

[erico]

If you are asking about a prebuilt product the answer is simple.

HP Engineers design the complete system. They ensure that the installed video card that has the specifications that will work with the motherboard and PSU that is installed in it. That is a requirement before putting a desktop PC in the marketplace.

They know how many watts a specific video card will require. THey are aware of how many watts all of the components of a PC require.

The video cards that HP uses are built to the specifications required by HP from the basic design provided by the manufacturer.

[AmpLighter]

Thanks as I am aware of the manufacturing process nd how engineers select the computers components accordingly. But the issues remains. If the video card manufacture requires a 350 watt or better power supply in conjunction to a particular video card for it to perform correctly, then why is this card installed in a system that has a lesser power supply? 

I also assume that the video card would not draw a constant 350 watts, but still it baffle me to think a lesser power supply would be placed in a computer with a video card that requires a greater power supply. 

[erico]

It is clear that, as you stated, it baffles you.

Your concern is not really warranted. They work and are guaranteed to work.

The video cards that are installed are of a design specification called for by the engineers who match their requirements with a PSU  and motherboard which will be installed in a destop PC. If you looked up the part number of the video card  an HP PC is delivered with, you might notice that generally there is also an HP part number on the card.

That is it, plain and simple.

If you were building a custom PC, as I and other experts here do, you would looking at candidate component requirements.  You are not doing that. You are looking at prebuilt and designed desktop PCs and wondering why they are the way they are.

Why would you think that a mainstream Radeon r7 video card would draw 350 Watts?  If it did that at any time, there would have to be something terribly wrong with the card. 😉

A 350 Watt PSU supplies current to various components of the PC not  only the video card.

  "I also assume that the video card would not draw a constant 350 watts, but still it baffle me to think a lesser power supply would be placed in a computer with a video card that requires a greater power supply." 

If it bothers you then you could always upgrade the PSU to something beastie. I usually install PSUs in the 750 W and greater class.

[CF4]

Hi

Here is a suggestion... 

AMD Radeon R7 370

500W (or greater) power supply with 1 x 75W 6-pin PCI Express power connector recommended
600W (or greater) power supply with 2 x 75W 6-pin PCI Express power connectors recommended for AMD CrossFire™ technology.

So my explanation is...

The PSU runs the TOTAL machine, the Radeon probably uses 100 watts max. 

Efficient cooling reduces the load by eliminating extra fans.

GPU's are more efficient the CPU's so the Load is lowered for the CPU.

It is Tailor Made, the motherboard tracks are not made to carry that kind of current, hence the 6 pin plugs.

Surely adding another another R7 370 would add 350 watts and the PSU spec would jump from 500W to 850W.

So AMD dont really give the power consumed, but make a statement as to their expectation.

[AmpLighter]

All then, last question let's suppose that I'm interested in the up pavilion 570 p017z computer. According to the site it says the video card is an AMD Radeon R7 but does not give what model it is IE: 260, 260x 250 230 etc. I've reached high & low for this information. Does anyone have a link the the cards series number?

[Big_Dave · Accepted solution]

@AmpLighter

The HP OEM Radeon AMD card is the R7 450 2GB that is provisioned in the 570-p017z.  COSTCO offers the 570-p017z.

@CF4

The Radeon AMD R7 370 is rated at 100 watts.

You also need to consider the PSU efficiency.  Some of HP newer 300 watt PSUs are equipped to handle graphics cards requiring a 6 pin PCIe auxiliary power connector.  This would be the 90% efficient 300 watt PSU models, but perhaps not all of them.  The older HP 300 watt PSUs were in the 60-70% efficiency range and didn't supply PCIe auxiliary power connectors.

[AmpLighter]

Thank you @Big_Dave  just what I wanted to hear.

As  follow up, I went to an AMD reference site just to find out where a R7 450 cards fits into a manufactured time frame. According to a wiki site, the 450 was manufactured June 2016 so it is really new. If one wanted to research when card is better than an R7, in sequence, the RX series numbers would be next. Knowing the series number which Big_Dave helped locate is just part of the puzzle as I didn't want to buy an already outdated computer. 

Again thanks to people like Big_Dave for his support.