"How many watts do I need"? Check Here!

[Bhav]

5 minutes ago, mariushm said:

Yeah, because the fan doesn't use 1-2 watts to spin. Congrats, you improved efficiency by 0.01% and you have a silent PC but you're keeping your power supply much hotter in return.

 

Basic physics and economics dude.

 

The 550w power supplies have to be sold at some price, there's bigger competition in that segment compared to 1000w and up market where manufacturers can charge more.

 

Why can't you people even read? That's not even what I stated, I stated two separate parameters:

 

A) The fan doesn't switch on until 800+ watts use = silence

B) At the same wattage usage up to 800w, the 1000w unit is approximately 2% more efficient than the 850w one.

[Bhav]

15 minutes ago, mariushm said:

A 550w power supply may use smaller heatsinks relying on air flow

Ok then, spot the difference:

 

850 watt -

 

 

 

1000 watt -

 

 

Why does the 1000w one run cooler even without the fan running at the same loads as the 850w one with its fan running? Maybe because none of you keyboard experts actually understand anything about the physics or chemistry into how these PSUs actually work (I'm not claiming that I do either, I'm simply observing and concluding based on the results).

 

You know what, I'll email EVGA / ask on their forums. I might not be able to today but I'll remember to do so eventually.

[mariushm]

There are differences if you take the time to analyze them.

 

The 1000w uses different fan..  b1402512HH (12v 0.5A 1800 RPM, 70,000-hour MTBF)  vs b1402512m (12v 0.3A ~1200-1300rpm 92.16 CFM, 24.9 dBA, DBB ) .. The 1600w one uses the one with EH at the end, which is 12v 0.6A, 2000 RPM, 153.47 CFM, 39.5 dB(A)

The 1000w uses  12 mosfets for 12v output, the 850w uses only 8 ...

 

Each mosfet has a Rds(on) property and other characteristics which vary with the amount of current that goes through them , and how warm they are... 500w at 12v though 12 mosfets is only 500w / 12 / 12 = 3.5A per mosfet, while with 8 mosfets you have 5.2A per mosfet. The mosfets may be slightly more efficient with 3.5A going through them, compared to having 5A going through them.

 

There's other smaller differences, like the 1000w model using 3 x 390uF capacitors on primary side and the 850w one using 3 x 330uF ... it's not a big difference but the higher capacitance can affect how the active power factor correction circuit works and how efficient it is, and it can also affect the switching frequency through the main transformer which could result in some efficiency values changing. 

 

I picked these up just by reading the text on jonnyguru's review of the two models, you could have done this yourself.

[Bhav]

6 hours ago, mariushm said:

There are differences if you take the time to analyze them.

 

The 1000w uses different fan..  b1402512HH (12v 0.5A 1800 RPM, 70,000-hour MTBF)  vs b1402512m (12v 0.3A ~1200-1300rpm 92.16 CFM, 24.9 dBA, DBB ) .. The 1600w one uses the one with EH at the end, which is 12v 0.6A, 2000 RPM, 153.47 CFM, 39.5 dB(A)

The 1000w uses  12 mosfets for 12v output, the 850w uses only 8 ...

 

Each mosfet has a Rds(on) property and other characteristics which vary with the amount of current that goes through them , and how warm they are... 500w at 12v though 12 mosfets is only 500w / 12 / 12 = 3.5A per mosfet, while with 8 mosfets you have 5.2A per mosfet. The mosfets may be slightly more efficient with 3.5A going through them, compared to having 5A going through them.

 

There's other smaller differences, like the 1000w model using 3 x 390uF capacitors on primary side and the 850w one using 3 x 330uF ... it's not a big difference but the higher capacitance can affect how the active power factor correction circuit works and how efficient it is, and it can also affect the switching frequency through the main transformer which could result in some efficiency values changing. 

 

I picked these up just by reading the text on jonnyguru's review of the two models, you could have done this yourself.

Note that you included a different review I hadnt yet found for the 1600w unit, and I wasnt comparing that one. I've emailed EVGA to confirm if the 850w and 1000w units simply use different fans to maintain 50c at max load, if thats the case then you are correct, they operate at the same temps at same loads. 

 

Also the thing is as per the review you included for the 1600w, while the fan specification may be listed as such, I am yet to find it written in a single such review in plain text that different units of the same type in different capacities simply use different fans. There are also no direct comparison / tests I can find as such comparing identical PSUs of different wattages for their thermals and noise levels, any such tests would easily clear this up if anyone did them.

[Bhav]

I did manage to just find this:

 

 

Quote

It is true that efficiency tends to decline as load goes above 50-60%.

 

 

This and just about every such review does confirm that efficiency rating DROPS above 50-60% use. This is exactly as I am claiming that by buying a higher wattage PSU, you will be able to stay within higher efficiency. No one and no information on PSUs discredits this advice, the only thing that some of you pointed out as mentioned already is that some newer PSUs maintain peak efficiency at 20-50%, which completely supports what I am claiming that if you want your PC / PSU to run more efficiently and use less power, then you absolutely should buy a higher rated PSU that allows you stay within its range for maximum efficiency. Lots of people including Linus already do this, and they are correct in doing so for higher efficiency use, which also means LESS power used and lower temperatures if you stay within a PSUs maximum efficient range of typically <60% maximum load.

 

So back to the initial comparison between an identical 550w and 650w PSU. If buying the 650w one instead allows, and it more than likely would, to run the PSU closer within in maximum efficiency range, then for a mere extra $15 there is absolutely nothing wrong with buying the higher rated PSU, and it will actually reduce power usage and thus reduce thermals.

[mariushm]

God ... dude, you can see the fan in the pictures of the power supply.

 

JonnyGuru review : EVGA T2 850w :  http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=462

 

JonnyGuru review : EVGA T2 1000w : http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=459

 

JonnyGuru review : EVGA T2 1600w : http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=410

 

TechpowerUp review : EVGA T2 1600w : https://www.techpowerup.com/reviews/EVGA/SuperNOVA_T2_1600/4.html

 

If you can read (you should cause you're answering to my messages), click on the pictures with the fans and you can see the fan model there.

 

They're using different fans in order to have enough air flow at maximum output to keep the internals below some temperature threshold. 

When the 1600w psu outputs 1600w with 90% efficiency, it will produce over 120-150w of heat which must be pushed out.

The 1000w producing 1000w with around 90% efficiency will only have to deal with 1000w of heat, so less powerful fans will produce enough air flow for that.  Simple physics.

 

Again it's not just the fan, you're stuck there. There's more capacitance on the primary side (the 1600w has 4 capacitors, the 1000w has 3, the 850w has 3 smaller ones), the bigger models have more mosfets on the secondary side (more mosfets = more surface area for heat to be dissipated in air, cooler chips which may mean more efficient chips)

 

I'm not surprised you can'd find such tests because the electronic loads that would pull 1000-1600 watts for hours from such power supplies also have to be cooled and the fans of those electronic loads would be MUCH louder than the psu fans... and most review websites don't have thousands of dollars to invest in electronic loads capable of "eating" 1000w or more.

 

Techpowerup, Tom's Hardware and a few others have access to labs with the proper instruments for them. Techpower up does a good job listing the internal components and showing clear pictures, that's why i link to them and that's the site from where I got the data of each fan (because Globe Fan's website is useless).

 

[Bhav]

12 minutes ago, mariushm said:

God ... dude, you can see the fan in the pictures of the power supply.

 

They're using different fans in order to have enough air flow at maximum output to keep the internals below some temperature threshold. 

This isnt something which is easy to notice when reading such reviews. People dont click on every picture and read all the fine print written on them.

 

But ok, the higher rated units do use higher rated fans.

 

HOWEVER:

 

12 minutes ago, mariushm said:

There's more capacitance on the primary side (the 1600w has 4 capacitors, the 1000w has 3, the 850w has 3 smaller ones), the bigger models have more mosfets on the secondary side (more mosfets = more surface area for heat to be dissipated in air, cooler chips which may mean more efficient chips)

This would therefore support that at equal loads, the higher rated PSUs would be able to remain cooler and thus generate less noise / continue running passively / on a lower fan RPM for longer, which is exactly what I was already claiming. Even if the difference only amounts to 1-2 degrees lower temperatures due to better passive cooling, this would still mean that the higher rated units are able to run at lower temperatures and thus have lower fan use. 

 

This is no different to people wanting to shave off as much of the heat from their CPUs as possible, so if you actually do want a unit that can remain cooler and quieter under the same loads, then this as I was saying all along is also more reason to buy a higher rated PSU.

 

I have just emailed EVGA to ask about any possible thermal / noise / efficiency differences at the same loads on these PSUs, so lets wait for their reply.

[mariushm]

13 minutes ago, Bhav said:

This would therefore support that at equal loads, the higher rated PSUs would be able to remain cooler and thus generate less noise / continue running passively / on a lower fan RPM for longer, which is exactly what I was already claiming.

Sure, if you have to be stubborn and feel that you need to twist everything to "win" an argument, i give up.

13 minutes ago, Bhav said:

I have just emailed EVGA to ask about any possible thermal / noise / efficiency differences at the same loads on these PSUs, so lets wait for their reply.

Good luck with that. Wait by the phone or computer, I'm sure their high paid engineers will rush to answer your email with thorough explanations to your frankly ridiculous questions.

[Bhav]

41 minutes ago, mariushm said:

Sure, if you have to be stubborn and feel that you need to twist everything to "win" an argument, i give up.

Good luck with that. Wait by the phone or computer, I'm sure their high paid engineers will rush to answer your email with thorough explanations to your frankly ridiculous questions.

I think you'll find it's called 'customer service' and EVGA are typically very good at that.

 

The only reason why this argument happened is because you lot can't accept that specifying a higher PSU for just a little more cost is actually beneficial and completely fine. Like there's such a huge problem getting a 650w unit over a 550w, especially if doing so demonstrably leads to higher efficiency and less noise.

 

It's funny really, Ive read just about every single other technical forum's take on this issue, not one single one will claim any negativity, and rather the opposite to overspecifying the PSU, except for you few keyboard warriors on this one.

[mariushm]

I only contradicted one of your statements, because it was incorrect. You couldn't let it go even though i corrected you time and time again trying to explain why you're wrong, yet you keep going on...

I never discussed at any point whether it's beneficial or not to specify a higher psu for just a little more cost, and at this point I don't want to.

[Bhav]

Just now, mariushm said:

I only contradicted one of your statements, because it was incorrect. You couldn't let it go even though i corrected you time and time again trying to explain why you're wrong, yet you keep going on...

I never discussed at any point whether it's beneficial or not to specify a higher psu for just a little more cost, and at this point I don't want to.

Because nobody else in the world makes mistakes,  everyone is perfect and already fully understands 100% of all knowledge. 

[seon123]

12 minutes ago, Bhav said:

Because nobody else in the world makes mistakes,  everyone is perfect and already fully understands 100% of all knowledge. 

And accepting any mistakes is a weakness, and should never be done... /s

[Bhav]

1 hour ago, seon123 said:

And accepting any mistakes is a weakness, and should never be done... /s

I prefer to make mistakes and learn.

 

I don't accept mistakes because I was raised by hardcore Asian parents that punished me for only 99% on a test due to a single spelling mistake for panc(h)reas, and then didn't even bat an eyelid when I actually got 100% on my next test, only to again repeat the above punishments for only getting straight Bs and not a single A grade in my final exams, oh and likewise for playing a single note wrong in a 5 minute piano recital.

[Stefan Payne]

1 hour ago, Bhav said:

The only reason why this argument happened is because you lot can't accept that specifying a higher PSU for just a little more cost is actually beneficial and completely fine.

You have to see the context. And that is what you are missing. You assume a rule that the higher wattages are always better - wich is wrong. And that is what you don't want to see right now.

 

In Germany, when someone wants to get a be quiet Dark Power Pro for two graphics card, everyone recommends the 850W instead of the 750W.

While for Corsair HXi, they don't. Because the HXi uses the same plattform, the Dark Power doesn't.

 

As for the 550 to 650W version: Nobody recommends that. Because the people know about the diagram where the 550W P10 at 100% has lower fan RPM than the 650W at 10%. And be quiet uses many different fans for many different unis.

The same for Bitfenix Whisper M, 550W is recommended, 650W is not because of the changed fan (0,6A instead of the 0,45A one).

 

1 hour ago, Bhav said:

Like there's such a huge problem getting a 650w unit over a 550w, especially if doing so demonstrably leads to higher efficiency and less noise.

Yes it is because there is no advantage in this area. Most 550 and 650W units use the same plattform, the Change in Plattform happens either with the 750W or 850W depending on how the series is made and the wattage of those. 

For Corsair RMx/RMi the change is at 750W wich uses a different plattform than the 650W. and with the be quiet Dark Power Pro P11 it is 850W.

And that fact changes everything. Because we are essentially talking about two completely different PSU.

 

Here some pics:
http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=467 850W Dark Power P11

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=469 550W

 

Corsair RMx/i:

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=445 550/650W

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=432 750W

 

It should be obvious why the bigger one in those cases can be beneficial and offer more advantages in every way while the same plattform often is not.

In many cases the electrical performance gets worse with the higher wattage models.

But also you have either no advantage at all so pay money for nothing or you loose something like quieter Operation wich the lower wattage versions sometimes have.

 

So what I'm saying is that you have to look at the units you are reommending.

But a rule of the Thumb:
650W is Nonsense in 9 out of 10 cases. Only with High End Desktop systems with (Ultra) High End graphics card and OC the 650W makes sense. 
Everyone else can not use it...

 

 

1 hour ago, Bhav said:

It's funny really, Ive read just about every single other technical forum's take on this issue, not one single one will claim any negativity, and rather the opposite to overspecifying the PSU, except for you few keyboard warriors on this one.

Yes, because they don't know shit about PSU and didn't read up on it or think about it like I do.

If you take 5minutes of time, it should be obvious why two units that use the same heatsinks, have about the same efficiency can not have any positive differenca at any load!

 

You have to change one of those mentioned factors go get a change - increase the size of the Heatsinks or Increase the efficiency for it to be different.

 

If those factors are the same - there can not be any advantage in the noise department.

 

I really don't understand why people think that less load = less noise because that violates the rules of thermodynamics...

[sendgik2]

Hi all,

 

I built my current system about 4 years ago and I am pretty sure the power supply is a very low grade unit. Here is my system:

 

Cpu:
    Intel i5 4690K 3.5GHz

GPU:
    ZOTAC GeForce GTX 970 4GB, ZT-90101-10P

PSU:
    ULTRA LSP750

Motherboard: 
    ASUS Z97-AR

RAM: 
    CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMZ4GX3M2A1600C9B

CPU cooler:
    probbaly cooler master hyper 212 (evo?) but not sure

Case:
    CM 690 NVIDIA Edition

HDD:
    Western Digital Blue WD5000AAKS 500GB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive Bare Drive
    WD Black 1TB Performance Desktop Hard Disk Drive - 7200 RPM SATA 6Gb/s 64MB Cache 3.5 Inch - WD1003FZEX

SSD: 
    PNY Optima SSD7SC240GOPT-RB 2.5" 240GB SATA III Synchronous-Mode Internal Solid State Drive (SSD)

 

I have tried figuring out what type of PSU I should replace my current with. I have looked at the high load requirement for  CPU/GPU added plus 100 and get 88+145+100 = 323W. But looking at similar setups everyone recommends at least 500W, 600 to be safe/ideal.

 

I have also looked at Corsair/CoolerMAster/EVGA and other websites to estimate the power my system  pulls but the results range form 300 to 500. Needless to say I am confused.

 

I am rather new to all of the technical specifications but do understand how electricity/rails/efficiency works.

 

Suggestions? I am thinking a 500W for mild overclocking since I am not looking to upgrade till 2020.

[Stefan Payne]

On 19.1.2018 at 12:54 AM, Bhav said:

I prefer to make mistakes and learn.

 

Then stop going into a discussion guns blazing, if you don't know enough about a subject and just believe what some random people on the Internet said.

Sometimes its better to just ask and not act like you are the right one - because if you are not, the backlash will be rather uncomfortable-

 

11 hours ago, sendgik2 said:

I built my current system about 4 years ago and I am pretty sure the power supply is a very low grade unit. Here is my system:

PSU:
    ULTRA LSP750

 

I have tried figuring out what type of PSU I should replace my current with. I have looked at the high load requirement for  CPU/GPU added plus 100 and get 88+145+100 = 323W. But looking at similar setups everyone recommends at least 500W, 600 to be safe/ideal.

 

 

Suggestions? I am thinking a 500W for mild overclocking since I am not looking to upgrade till 2020.

400-550W is enough, 500-550W to be on the 'safe Side', no need for 600W wich is nonsense anyway because there isn't any practical use for that - except if you do sledgehammer overclocking without any regard for your components lifetime.

 

But wattage is irrelevant, quality of the PSU counts!

 

So you can be better of with a 450W Bitfenix WhisperM or Formula instead of a 600W EVGA B1 or something like that...

 

 

So what PSU are you thinking about? What's available?

[sendgik2]

On 1/20/2018 at 8:47 AM, Stefan Payne said:

 

So what PSU are you thinking about? What's available?

I went with CORSAIR TX Series TX750M 750W 80 PLUS Gold Modular Power Supply because it was on sale and will allow for upgrading my system down the road. Also runs just over 10 db

[Illbefrank]

So, I used multiple PSU wattage calculators and am still not certain on the amount of watt I need.

Some websites don't even account for any display(s) used, which I believe is relevant?

 

My system:

Case: NZXT H440 New Edition (comes with 4 fans: 3x 120mm & 1x 140mm)

Mobo: Asus ROG STRIX Z370-F Gaming

CPU: Ryzen 5 1600x

CPU Cooler: Scythe Mugen 5 PCGH Edition

RAM: 2x 8GB G.Skill Trident Z 3200 MHz RGB (F4-3200C14D-16GTZR)

GPU: Asus ROG STRIX GTX1070-O8G

SSD1: Samsung 960 EVO MZ-V6E250BW (250GB)

SSD2: Random 1TB SATA-SSD

Display: Asus ROG Swift PG258Q

 

Additional info:

• I intend to overclock a little.
• I intend to add another screen later
• No intentions to add another GPU, only upgrade it to a 1080 (Ti) when stock and prices allow me to (probably 2019Q2)
  • at that point I will have upgraded my display also

The PSU I've been looking at is the: Be quiet! STRAIGHT POWER 11 550W

Of course I'm afraid of underpowering my system and rendering it unable to elect a new pope (emitting a puff of black smoke).

On the other hand, why put a 750W PSU in my case, if it will never use 1/3 of it...?

 

You lot sound pretty smart, or at least have a lot more experience than me, with my first 'decent' build...

[mariushm]

The motherboard will use around 20-40 watts.

The processor at stock frequencies will use around 60 to 80 watts. 

Ryzen processors peak at around 140 watts for 8 cores at 4 Ghz and 1.42v voltage (the maximum) so around 18w per core. If you overclock to extreme, your 6 core Ryzen will use up to around 100 watts and the voltage regulator on the motherboard will waste around 20w as heat, so around 120w in total. 

The GTX1070 uses up to 150 watts, if you overclocking it a lot, you may get up to 200 watts.

The memory uses 2-3 watts per stick

The fans use around 2 watts each

The cooler will use maybe 5-10 watts

A hard drive (mechanical) averages around 5-8 watts

A SSD averages around 2w (jumps to  5-10w for milliseconds at a time when it's writing data to flash chips, othewise reading and idle-ing takes less than 1w)

 

So without overclocking, your system probably uses around 200 watts when gaming. When watching movies, browsing etc you're probably looking at 50-80 watts at the mains socket.

 

[Illbefrank]

50 minutes ago, mariushm said:

The motherboard will use around 20-40 watts [....] So without overclocking, your system probably uses around 200 watts when gaming. When watching movies, browsing etc you're probably looking at 50-80 watts at the mains socket.

Thank you for the detailed information on wattage per part, as well as in case of an overclock. Very helpful indeed.

I'm surprised at how little the estimated power consumption is for my system.

I can get a deal on the aforementioned PSU, so I'm comfortable with ordering it now.

 

Thanks again

[Delta-c-tech]

500 Watts Would be a good Start For Any Pc

[turkey3_scratch]

3 minutes ago, That One Kid said:

500 Watts Would be a good Start For Any Pc

Not necessarily.

[Stefan Payne]

2 hours ago, turkey3_scratch said:

Not necessarily.

Yes,  if we talk about extremes like PCs without Graphics cards and HEDT systems with High End Graphics cards.

But usually 500W +/- 50W is a good start.

 

You must NEVER EVER make rules for the exceptions ever!!

[Aniallation]

Just here for my 20,000th post.

[ZhangirDuyseke]

How many watts do i need for this system? 
Processor: Intel Core I7-8700K (i am going to overclock it to 5.2Ghz)

Motherboard: Asus ROG MAXIMUS X HERO (Wi-Fi ac)
CPU Cooler: Corsair H150i
Memory: Corsair Vengeance RGB 32Gb(2x16Gb) 3600Mhz

Graphics Cards: 2xAsus ROG Geforce GTX 1080Ti oc(SLI) going to overclock it as well

Storage: Samsung SSD 960 Pro 2Tb m.2

Fans: 6 LL120 RGB Corsair fans

I've ran some tests, and used power supply calculators but they give different results. Is HX850i Corsair Power supply enough for this rig, or do i need 1000W?