Question How much Power do I really need?

Nov 17, 2021
53
0
30
So I want to get a new psu, since my old one was always constantly turning off for no real reason. I don't really want to spend too much on a power supply, however, so I need some tips. Say if there is enough connectors for everything I need, does that mean it is enough power? If not, here are my specs:
MB: hp elitedesk 800g1 sff
PSU: Undetermined
Cpu: Xeon e3 1220 V3
Cooler: Stock
RAM: 8gb ddr3
gtx 770 2gb gddr5
2tb 7.2k rpm HDD
256gb (I think) PM851 samsung SSD
5 ~1200 rpm fans
I was thinking if a 550w psu would be enough.
Thanks!
 

AntonyLovric

Distinguished
I think that PSU is proprietary (PSU connector is not standard ATX.) Those SFF PSUs also only provide 240ish watts. You can't easily replace it, but you can buy a new PSU and get the HP PSU adapter for your model like this:

Adapter

You will need to figure out if the case has enough airflow without the PSU installed in it. Work out some kind of tuck tape tunnel for the new PSU maybe? It's that OR you hook up a separate PSU via something like Add2PSU with a spare (or split off ) SATA connector.

Or try to transplant to a larger HP / other case?
 
Your pc is not designed to be upgraded.
Is this is your unit and specs?
https://support.hp.com/us-en/produc...orm-factor-pc/5387475/document/c03832938#AbT4

If so, the supplied psu is 320w.
It is likely to be proprietary as is the motherboard.
Are you looking to install a GTX770?
Not gonna work.
First, you need more power:
https://support.hp.com/us-en/produc...orm-factor-pc/5387475/document/c03832938#AbT4
second, a sff will not handle a conventional graphics card; you would need a low profile card.
GT1030 would be the strongest you could use.
 
Nov 17, 2021
53
0
30
I think that PSU is proprietary (PSU connector is not standard ATX.) Those SFF PSUs also only provide 240ish watts. You can't easily replace it, but you can buy a new PSU and get the HP PSU adapter for your model like this:

Adapter

You will need to figure out if the case has enough airflow without the PSU installed in it. Work out some kind of tuck tape tunnel for the new PSU maybe? It's that OR you hook up a separate PSU via something like Add2PSU with a spare (or split off ) SATA connector.

Or try to transplant to a larger HP / other case?
Oh, I have an adapter. I actually already have the build, but it is annoying since it keeps turning off randomly, and it takes many attempts for it to turn on. Sometimes for 15ish minutes I'll just sit and press the button, hoping it will turn on. In terms of the case I have this, (in white.) https://www.newegg.com/p/N82E16811353203
 
Nov 17, 2021
53
0
30
Not quite. GTX 770 is 230W GPU and bare minimum i'd use with that, would be 600W range PSU, while 700W range would be more comfortable.

Good PSUs to go for, are Seasonic Focus and PRIME series. On Corsair side: RM, RMi, RMx, HX, HXi, AX and AXi.
But would it work? Some people over at linustechtips forums said it would be plenty. (sorry if I sound snobby)
 
Nov 17, 2021
53
0
30
Your pc is not designed to be upgraded.
Is this is your unit and specs?
https://support.hp.com/us-en/produc...orm-factor-pc/5387475/document/c03832938#AbT4

If so, the supplied psu is 320w.
It is likely to be proprietary as is the motherboard.
Are you looking to install a GTX770?
Not gonna work.
First, you need more power:
https://support.hp.com/us-en/produc...orm-factor-pc/5387475/document/c03832938#AbT4
second, a sff will not handle a conventional graphics card; you would need a low profile card.
GT1030 would be the strongest you could use.
I have a mid tower, I managed to swap the case with some nuts to screw into the CPU cooler.
 

Aeacus

Titan
Ambassador
But would it work?

Will your PC work with 550W unit? Well, on idle, yes.
But when you start gaming and putting a load on the PSU, it may result in the same issue you currently have - PC shutting down.

When it comes to PSUs, it's best when load on them is kept 50% to 80% of their max wattage rating, since at that range, PSUs are most efficient. 550W unit is pushing it way too much, working PSU hard, especially when Nvidia itself is suggesting at least 600W PSU for GTX 770.

100W headroom is minimum i'd be suggesting, while ~200W headroom is preferred. Since that also includes hardware power spikes, which are higher than normal wattage rating and it also can sustain CPU/GPU OC.

For example, my Skylake build (full specs with pics in my sig), in there, i have Seasonic PRIME 650 (80+ Titanium) PSU. If i were to add up all the hardware in it, the total load would be ~400W. Making 650W PSU a good fit. Now, i did measure my PCs power draw at full load (during benchmark) and at most, it pulled 212W from the wall. Nice. However, that doesn't mean i'd be downgrading my PSU.

Some people over at linustechtips forums said it would be plenty.

If it isn't plenty, and you need to go with higher than 550W unit, are they willing to pay for a new PSU?

Better be safe than sorry. And 650W or 750W PSU is also good when you eventually upgrade your hardware. Then you can bring over your PSU to a new build and not being stuck with average wattage PSU, limiting what upgrades you can make.
 
Last edited:
Nov 17, 2021
53
0
30
Will your PC work with 550W unit? Well, on idle, yes.
But when you start gaming and putting a load on the PSU, it may result in the same issue you currently have - PC shutting down.

When it comes to PSUs, it's best when load on them is kept 50% to 80% of their max wattage rating, since at that range, PSUs are most efficient. 550W unit is pushing it way too much, working PSU hard, especially when Nvidia itself is suggesting at least 600W PSU for GTX 770.

100W headroom is minimum i'd be suggesting, while ~200W headroom is preferred. Since that also includes hardware power spikes, which are higher than normal wattage rating and it also can sustain CPU/GPU OC.

For example, my Skylake build (full specs with pics in my sig), in there, i have Seasonic PRIME 650 (80+ Titanium) PSU. If i were to add up all the hardware in it, the total load would be ~400W. Making 650W PSU a good fit. Now, i did measure my PCs power draw at full load (during benchmark) and at most, it pulled 212W from the wall. Nice. However, that doesn't mean i'd be downgrading my PSU.



If it isn't plenty, and you need to go with higher than 550W unit, are they willing to pay for a new PSU?

Better be safe than sorry. And 650W or 750W PSU is also good when you eventually upgrade your hardware. Then you can bring over your PSU to a new build and not being stuck with average wattage PSU, limiting what upgrades you can make.
Okay then I have been using 600w. I think that should be good then, right? I mean the rtx 3060 ti with a ryzen 3600 can run at 600w, so it must be good, right?
 

Aeacus

Titan
Ambassador
I think that should be good then, right?

With PSUs, it's more to do with build quality than max output wattage. E.g good quality 550W unit will always outperform 750W junk PSU, since with good PSU, you can be sure that it does deliver what it is rated for + having all the needed protections; while junk PSUs often fail long before even reaching what their max output wattage is claimed for, and often lacking built-in protections as well.
 
Nov 17, 2021
53
0
30
So I did some calculations, and it seems like everything in total is about 315W, excluding the MB and CPU cooler, since I couldn't find info. You sure a 550W psu would be too little?
 

Zerk2012

Titan
Ambassador
So I did some calculations, and it seems like everything in total is about 315W, excluding the MB and CPU cooler, since I couldn't find info. You sure a 550W psu would be too little?
In general you can figure the TDP of the processor and video card under full load then add about 70 watts for everything else.

Unless your using a ton of drives or liquid cooling.

From their you would pick a quality PSU that would be using about 75% of the rated power.

Having some overkill is not a bad thing allowing for future upgrades.
 
Nov 17, 2021
53
0
30
In general you can figure the TDP of the processor and video card under full load then add about 70 watts for everything else.

Unless your using a ton of drives or liquid cooling.

From their you would pick a quality PSU that would be using about 75% of the rated power.

Having some overkill is not a bad thing allowing for future upgrades.
Aight, so I COULD definitely play intensive games with 550W, right? In terms of upgrades, I plan on getting a better PC in a year or 2, when the cough Gpu shortage ends
 

Zerk2012

Titan
Ambassador
Aight, so I COULD definitely play intensive games with 550W, right? In terms of upgrades, I plan on getting a better PC in a year or 2, when the cough Gpu shortage ends
I'm not going to look up the watts, you said 315 so 70 more for the rest and leave a little error room would put you about 400 watts so a quality 550 watt would put you in the 72% area is fine to me.
 

Zerk2012

Titan
Ambassador
Aight, so I COULD definitely play intensive games with 550W, right? In terms of upgrades, I plan on getting a better PC in a year or 2, when the cough Gpu shortage ends
I'll add one more thing don't cheap out over 15 or 20 bucks, you said upgrading in a couple years it would be better to spend a bit extra now and not need to buy a new one again 2 years from now.

59 bucks with some overkill but decent quality.
https://pcpartpicker.com/product/PV...d-semi-modular-atx-power-supply-cp-9020132-na

41 after the rebate, acceptable quality.
https://pcpartpicker.com/product/R2mxFT/corsair-power-supply-cp9020103na

EDIT when you get into a power supply discussion here your going to open a can of worms.
I'm using a Seasonic G series 650 watt with a overclocked 10600K can pull about 160 watts under full load with a RTX 2080 about 220 watts.

Also using extension cables that to most here is a big no.

Good quality power supply but not the best they had and it's 7 years old.

If you really look a lot of times the 650/750 watt models can cost less than the same 550 watt one.
 
Last edited:
Some graphics cards, particularly newer ones,
have power spikes well in excess of the nominal amount.
Such a situation is very hard to diagnose.
A psu will not draw more power than what is demanded of it, regardless of the max capability.
Usually going a step up will cost you perhaps $10-$20 more.

DO NOT buy a cheap psu.
Such units deliver advertised power only at room temperature.
Not at 50c. which you might find in a case.
The power may be delivered on minor voltages, not at 12v where modern processors and graphics cards need them.
Should a cheap psu fail when overloaded, it can damage all of your other parts.

Consider a quality psu as a long term investment.
 
Nov 17, 2021
53
0
30
I'll add one more thing don't cheap out over 15 or 20 bucks, you said upgrading in a couple years it would be better to spend a bit extra now and not need to buy a new one again 2 years from now.

59 bucks with some overkill but decent quality.
https://pcpartpicker.com/product/PV...d-semi-modular-atx-power-supply-cp-9020132-na

41 after the rebate, acceptable quality.
https://pcpartpicker.com/product/R2mxFT/corsair-power-supply-cp9020103na

EDIT when you get into a power supply discussion here your going to open a can of worms.
I'm using a Seasonic G series 650 watt with a overclocked 10600K can pull about 160 watts under full load with a RTX 2080 about 220 watts.

Also using extension cables that to most here is a big no.

Good quality power supply but not the best they had and it's 7 years old.

If you really look a lot of times the 650/750 watt models can cost less than the same 550 watt one.
hmm, nice psu for the second one. Probably going to get that.
 
Nov 17, 2021
53
0
30
I would get the first one cost you the same out of pocket, better quality and a 7 year warranty.

EDIT your money and either will work for what your building.
And like I said when you ask a PSU question here you open a can of worms.
Aight so do you think a 650W 80+ Bronze Aresgame PSU would be Okay? It's brand new.