# Motherboard wattage



## yahn

How do you figure out the wattage a motherboard needs?  The PSU calculators that I've seen just estimate the wattage based on whether it has integrated graphics or not.

Is there a good way to estimate it?  Do ATX, mATX, and ITX boards need different wattages?

Thanks,


----------



## Jc61990

whats your setup?

its usually not much, the cpu and video card usually eat up most of the power

try this http://extreme.outervision.com/psucalculatorlite.jsp


----------



## yahn

> whats your setup?



Well, I'm thinking of purchasing used SFF business computers in bulk, but I need to know how much extra power the PSU has so that I know what I can add to them.

I had an SFF Dell PC a few years ago and added an 64 MB AGP graphics card and memory with no issue.  But, some of these SFF PCs only have a 140W-185W PSU.  I'm wondering what will be left over after the 89W from the processor, 30W from the RAM, and 30W from the HDD.  I read that AGP cards use 30W-50W of power, but I'm not able to find out the wattage on the card either.


----------



## Jc61990

http://www.gpureview.com/videocards.php

this site has a lot of information about almost every video card. it should show max power consumption


----------



## StrangleHold

Really hard to tell. The chipsets dont use much, unless it has onboard video and you are using it. What kind of CPU you use pulling through the CPU power connector. Or what video card you using, most PCIe slots can pull up to or alittle more then 75W, plus if it has PCIe power connectors, but those are really pulling straight through the power supply and not through the board. If you have any PCI cards.

Alot of things will make it vary.


----------



## linkin

Boards don't generally use much themselves, they get it from the power supply and give it to the components through the motherboard. A good way to guesstimate usage is add the TDP of your CPU, GPU, HDD and any other parts that have it listed and there's your maximum power draw if all components are under 100% load.


----------



## yahn

> Boards don't generally use much themselves, they get it from the power supply and give it to the components through the motherboard. A good way to guesstimate usage is add the TDP of your CPU, GPU, HDD and any other parts that have it listed and there's your maximum power draw if all components are under 100% load.



That's what I figured, but I've been looking at PSU wattage calculators and, unless I'm looking at them wrong, they are adding 30W-60W for the motherboard.  That's not a lot, but, at the same time, I'd like to figure out what exactly it is so that I know how much wattage I'll need.

Is 30W-60W a good estimate?  There's a huge difference between the two and it seems way too high.  I don't want to randomly add 60W to every system unnecessarily...


----------



## linkin

That 30-60W is probably for the RAM more than anything else. Generally, I take the TDP of my components and add 150-200w for overclocking/other components.


----------



## MMM

POWER REQUIREMENTS for computers

This guide will give you an idea as to what capacity Power Supply you will require when building your own or upgrading your PC.

Add up the power needs of all your components of your computer to find out what size PSU you need.
Aim for around 50-70% of total capacity which should still leave room for upgrade expansion.

MOTHERBOARD
A small board for compact PC's                25W
An average Desktop motherboard                35W
A high end motherboard                      50W

INTEL PROCESSOR
Core 2 Duo 8xxx                               65W
Core 2 Duo 9xxx                               95W
Core 2 Quad                                   95W
Core 2 Duo Extreme                            150W
Core I3                                       75W
core I5                                       95W
Core I7-8xx                                   95W
Core I7-9xx                                   130W

AMD PROCESSOR
Athlon II X2 'e'                              45w
athlon II X2                                  65W
Athlon II X3                                  45W
Athlon II X4                                  95W
Phenom II X2                                  80W
Phenom II X3                                  95W
Phenom II X4  X6                              140w

Graphics card
AGP or lesser with no extra power             50W
PCI-E with no seperate power supply           75W
PCI_E with 6 pin connector                    150W
PCI-E with two 6 pin connector                225W
PCI-E with 8 pin connector                    225W
PCI-E with 8 pin and 6 pin connector          300W

MEMORY
Single stick of DDR                           6W
Two sticks of DDR                             12W
Four sticks of DDR                            24W
Two sticks of DDR2                            8w
Four sticks of DDR2                           16w
Two sticks DDR3                               6W
Four sticks DDR3                              12w
Six sticks of DDR3                            18w

Fans                                    5w to 10W

Optical Drives                                10W

IDE Hard Drives                               15W

SATA Hard Drives                              10W

Solid State Hard Drives                       10W


As mentioned it will give you an idea of your power supply requiremnts

Brand name Power supplies your choice.

Cheers


----------



## linkin

MMM said:


> POWER REQUIREMENTS for computers
> 
> This guide will give you an idea as to what capacity Power Supply you will require when building your own or upgrading your PC.
> 
> Add up the power needs of all your components of your computer to find out what size PSU you need.
> Aim for around 50-70% of total capacity which should still leave room for upgrade expansion.
> 
> MOTHERBOARD
> A small board for compact PC's                25W
> An average Desktop motherboard                35W
> A high end motherboard                      50W
> 
> INTEL PROCESSOR
> Core 2 Duo 8xxx                               65W
> Core 2 Duo 9xxx                               95W
> Core 2 Quad                                   95W
> Core 2 Duo Extreme                            150W
> Core I3                                       75W
> core I5                                       95W
> Core I7-8xx                                   95W
> Core I7-9xx                                   130W
> 
> AMD PROCESSOR
> Athlon II X2 'e'                              45w
> athlon II X2                                  65W
> Athlon II X3                                  45W
> Athlon II X4                                  95W
> Phenom II X2                                  80W
> Phenom II X3                                  95W
> Phenom II X4  X6                              140w
> 
> Graphics card
> AGP or lesser with no extra power             50W
> PCI-E with no seperate power supply           75W
> PCI_E with 6 pin connector                    150W
> PCI-E with two 6 pin connector                225W
> PCI-E with 8 pin connector                    225W
> PCI-E with 8 pin and 6 pin connector          300W
> 
> MEMORY
> Single stick of DDR                           6W
> Two sticks of DDR                             12W
> Four sticks of DDR                            24W
> Two sticks of DDR2                            8w
> Four sticks of DDR2                           16w
> Two sticks DDR3                               6W
> Four sticks DDR3                              12w
> Six sticks of DDR3                            18w
> 
> Fans                                    5w to 10W
> 
> Optical Drives                                10W
> 
> IDE Hard Drives                               15W
> 
> SATA Hard Drives                              10W
> 
> Solid State Hard Drives                       10W
> 
> 
> As mentioned it will give you an idea of your power supply requiremnts
> 
> Brand name Power supplies your choice.
> 
> Cheers



May I ask where you got that info from? Handy to know.


----------



## MMM

linkin said:


> May I ask where you got that info from? Handy to know.


Two magazines in Australia worth reading with wealth of knowledge for computers phones and any thing else to do with the latest technology.

PC Tech&Authority and PC User, have been reading these for years and also a good book for you to read is Upgrading and Repairing PC's by Scott Mueller which by now would be releasing his 20th Edition.... one of the best reference books available... must have for any one.

I have been building and repairing computers since 1990, but not much these days as I only do it for a hobby now.


----------



## linkin

MMM said:


> Two magazines in Australia worth reading with wealth of knowledge for computers phones and any thing else to do with the latest technology.
> 
> PC Tech&Authority and PC User, have been reading these for years and also a good book for you to read is Upgrading and Repairing PC's by Scott Mueller which by now would be releasing his 20th Edition.... one of the best reference books available... must have for any one.
> 
> I have been building and repairing computers since 1990, but not much these days as I only do it for a hobby now.



Alright cheers, might check that out.


----------



## yahn

> That 30-60W is probably for the RAM more than anything else. Generally, I take the TDP of my components and add 150-200w for overclocking/other components.



I've also read that you only want to use 80% of your PSU.  I don't know if this is just a warning to keep you from going over, but it made sense when you look at the efficiency of the PSUs.



> Two sticks DDR3 6W
> Four sticks DDR3 12w
> Six sticks of DDR3 18w



Memory wattage is directly related to the amount of bytes of storage it has -- unless I've been disgustingly misinformed.  It also apparently matters on the type of components inside the chip.  I've read that some 4 GB sticks operate at 8W, so those figures could be way off.  But, seeing as I have no idea how that term was actually calculated, you could be right on the money.


----------



## linkin

> I've also read that you only want to use 80% of your PSU. I don't know if this is just a warning to keep you from going over, but it made sense when you look at the efficiency of the PSUs.



If it's a quality PSU it should be able to handle 120% load  But yes, the less you stress them, the longer they last.


----------

