Why group regulated units shouldn't be bought/sold in 2019 (and on)

[LukeSavenije]

These days the 12v is known to power almost everything: GPUs, CPUs, fans, part of the motherboard, sometimes DRAM (but is generally still 3.3v) and some PCs already fully work with it (converting it on the motherboard normally). This used to be different, with 5v being much more important than it used to be. From almost everything on the board, these days it's main use is powering storage. In this earlier era the "group regulation" design was made, and used for many years, even today on budget units from various popular companies including at the time of writing:

• Be Quiet - Pure Power 11 (300-350w only)
• Cooler Master - Masterwatt Lite
• Corsair - VS 2017
• EVGA - W1, N1, N2, BT
• FSP Hexa+, Hyper, Hammer, Raider, part of Aurum
• Seasonic - S12ii/M12ii
• Thermaltake - Smart 80+
• Xilence - Performance C

and many others, which are at the time of writing still widely available.

 

Problem 1: Group regulation and crossloads

the main problem with group regulated units is that it regulates 12v and 5v together. as noted above these days the only big use for 5v is part of the motherboard and storage, which keeps the load on it quite low, while modern systems have the heaviest components on 12v. In the PSU world we use the word "crossload" for loading up one rail a lot, while the others little to none (either from 3.3/5/12v). When the 12v is loaded up far enough, the controller can't keep the 5v in control, as they're reported together and starts to go out of ATX specification as the controller thinks it's only rising the 12v. especially since some of the units above don't have undervoltage protection, this can have results from shorter lifespan of components to in very bad cases burnt cables. ATX specification only allows a difference up to 5% between rails. They can also fail ATX specification easily when the minor (3.3/5v) are loaded up, while the 12v is kept at the minimal 0.1a 

 

Problem 2: Low load operation

The PSU is required to output voltages while the 12v is at only 0.05a, which is for most group regulated units impossible to do with the crossloading problems mentioned above. not meeting this is again a fail for ATX specification for Haswell.

 

Examples: Group regulated units failing ATX specification

http://www.jonnyguru.com/blog/2018/11/12/evga-750n1-750w-power-supply/3/

http://www.jonnyguru.com/blog/2018/10/08/cooler-master-masterwatt-lite-600w-230v-power-supply/3/

 

How do I recognize a group regulated unit?

The first way (if you have internal shots) is to look at the number of regulation coils. if two are present, it's a group regulated unit, at 3 it's individually regulated. The big coil is used for 12v/5v, the smaller for 3.3v.

 

The second indication that a PSU is group regulated is to look at the power distribution label. If the PSU says it can output a total a 600w but the 12v says it only outputs 400w, then that's an indication that it's group regulated.

Here's some images which hopefully provide additionally clarity to those that don't know. 

There are two sides to a PSU. Primary and Secondary. Won't go into details on the specifics here, The two coils boxed in red are located on the secondary side. 12v and 5v are regulated on the bigger coil and the small coil has 3.3v. Now a thing to consider here is that there is a secondary topology known as Dual Mag Amp, which has two magamp coils. Better than group regulation from a performance standpoint, but in general, it's not very efficient. I think the most you can achieve is bronze efficiency. Maybe silver. It can be easy to confused the two topologies. Now, sometimes, group regulation could use one coil. I've seen a few very old PSUs with just the one coil. (credit to JonnyGuru.com for this image.)

Below is a Corsair CX450, Boxed in red are the DC-DC converters. Now, this example shows the coils covered. But usually, the coils are exposed and mounted a daughter board(s). These regulate the minor rail outputs while the 12v is independently regulated.

 

Final verdict

If you can, get a DC-DC unit, or at least something individually regulated. If you can't, keept the 12v at a minimal level, for example not combining it with high end or even mid-low GPU's or powerful CPUs. They're simply not made for modern component use.

 

License:

Spoiler

These works by Luke Savenije et al. are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

 

Credit:

@PSUGuru

[Oalei]

3 minutes ago, LukeSavenije said:

The easiest way (if you have internal shots) is to look at the number of coils. if two are present, it's a group regulated unit, at 3 it's individually regulated. The big coil is used for 12v/5v, the smaller for 3.3v

Can I have some pictures example pls with some pointers so I can Know betters

[Fasauceome]

I take it this will be linked on the PSU tier lists?

 

And of course, "muh sources," linking some kind of data showing the negative side effects of that crossload would be nice so people get a good quantifiable representation of the impact that a group reg unit has on your PC, since it's not something you can see when you plug a 2080 ti into a VS 650 and turn it on.

[LukeSavenije]

7 minutes ago, Oalei said:

Can I have some pictures example pls with some pointers so I can Know betters

i'll see what i can do... i might use my realpower for it, don't think i have any other group regs in house

 

7 minutes ago, Fasauceome said:

I take it this will be linked on the PSU tier lists?

nope, this is just a spontaneous effort from me to explain why i don't like group regs

 

7 minutes ago, Fasauceome said:

And of course, "muh sources," linking some kind of data showing the negative side effects of that crossload would be nice so people get a good quantifiable representation of the impact that a group reg unit has on your PC

 i'll see what i can find... something to add in a bit too, maybe with the pictures of a group reg, though Aris does talk about this what i'm writing in his PSU 101

 

until then... time for more additions to it

[Vejnemojnen]

@LukeSavenije If you have some spare time, could you please add FSP "Hyper" S-K-M& FSP and older FSP Hexa+ series to the group regulated list? These are incredibly popular "here", just because they are FSP units. (same for Chieftek cheap units.. )

[LukeSavenije]

Just now, Vejnemojnen said:

@LukeSavenije If you have some spare time, could you please add FSP "Hyper" S-K-M& FSP and older FSP Hexa+ series to the group regulated list? These are incredibly popular "here", just because they are FSP units. (same for Chieftek cheap units.. )

oh, that one i can do right away, the other stuff requires some more research, but i didn't know FSP was still that popular, as it isn't around here

[Oalei]

1 minute ago, LukeSavenije said:

ll see what i can do... i might use my realpower for it, don't think i have any other group regs in house

I have some really old PSU maybe I can just open them up with my shoes on so I have lesser chance of getting electrucated to death.

[Fasauceome]

3 minutes ago, LukeSavenije said:

nope, this is just a spontaneous effort from me to explain why i don't like group regs

I'm at my 10 link limit for my sig  seems like there would be a place for a spoiler with relevant PSU related links to learn more?

[LukeSavenije]

Just now, Fasauceome said:

I'm at my 10 link limit for my sig  seems like there would be a place for a spoiler with relevant PSU related links to learn more?

i'll give it a thought... maybe something for rev 5, can't say for sure though

 

3 minutes ago, Oalei said:

I have some really old PSU maybe I can just open them up with my shoes on so I have lesser chance of getting electrucated to death.

oh, it's fine, i have one laying around

 

look at tier e and you'll understand what i meant with realpower

[Vejnemojnen]

1 minute ago, LukeSavenije said:

oh, that one i can do right away, the other stuff requires some more research, but i didn't know FSP was still that popular, as it isn't around here

Guess it's some post soviet block/Warsaw pact land phenomenon. 

[OrionFOTL]

Big mistake or misinterpretation of terms here:

25 minutes ago, LukeSavenije said:

Problem 2: Zero load

For C6/C7 specification, introduced with Haswell (4th gen Intel), the PSU needs to be able to meet a certain 0 load efficiency.

C6/C7 power states have nothing to do with neither 0 load, nor efficiency. They require the PSU to maintain output voltages when the load on 12V is only 0.05A, they don't specify any efficiency requirements and it's not 0 load either.

 

25 minutes ago, LukeSavenije said:

In the PSU world we use the word "crossload" for loading up multiple rails (either from 3.3/5/12v).

No, crossload is exactly the opposite of what you wrote. It's heavily loading one rail, while not loading the others. 12V-heavy crossload is when you put a big load on 12V and almost none on minor rails (like in modern computers without hard drives), and minor-heavy crossload is when you put a big load on the minor rails, and almost no load on 12V (doesn't happen).

I think this is just a phrasing error.

 

25 minutes ago, LukeSavenije said:

How do I recognize a group regulated unit?

The easiest way (if you have internal shots) is to look at the number of coils. if two are present, it's a group regulated unit, at 3 it's individually regulated. The big coil is used for 12v/5v, the smaller for 3.3v.

This is not specific enough - power supplies have many coils of many kinds in many different places, like the PFC coils, pi filter coils, input filter coils, and more. I can count 8 coils in a group regulated Corsair CX600M People who don't know what to look for may count them in.

Some power supplies also have two regulation coils, but aren't group regulated.

 

14 minutes ago, LukeSavenije said:

21 minutes ago, Oalei said:

Can I have some pictures example pls with some pointers so I can Know betters

i'll see what i can do... i might use my realpower for it, don't think i have any other group regs in house

I don't see why you'd have to make your own photos of it, there are tons of power supply photos on the internet which we've seen hundreds of.

[LukeSavenije]

2 minutes ago, OrionFOTL said:

C6/C7 power states have nothing to do with neither 0 load, nor efficiency. They require the PSU to maintain output voltages when the load on 12V is only 0.05A, they don't specify any efficiency requirements and it's not 0 load either.

i should have some fun with 2.32 and 2.4 soon... i got it sent today, probably something on my side

 

2 minutes ago, OrionFOTL said:

I think this is just a phrasing error.

i'll update that part soon-ish with the other stuff

 

2 minutes ago, OrionFOTL said:

don't see why you'd have to make your own photos of it, there are tons of power supply photos on the internet which we've seen hundreds of.

well... there's something called copyright unfortunately... so i might as well since i have one laying around, grab my nikon or my mi8 and mark some stuff down

 

guess to... just give me some time to edit some stuff out and note whenever i'm done 

[OrionFOTL]

12 minutes ago, LukeSavenije said:

i should have some fun with 2.32 and 2.4 soon... i got it sent today, probably something on my side

What do you mean "got it sent"? It's public on Intel's website

 

12 minutes ago, LukeSavenije said:

well... there's something called copyright unfortunately... so i might as well since i have one laying around, grab my nikon or my mi8 and mark some stuff down

Copyright law allows partial use of copyrighted materials for purposes of review, commentary, citation and similar; a single photo from a review with a credit link is completely fine. Look up "Fair use". I mean, if it really was so strict, then you wouldn't have movie/game/show reviews on youtube, couldn't use GIFs from those, and Youtube would have to be completely original content (that could be a good or bad thing, depending how you look at it lol)

But if you really wanna use your own PSU for that, go ahead! Nothing wrong with it.

[LukeSavenije]

1 minute ago, OrionFOTL said:

What do you mean "got it sent"?

awesomegamer sent it to me via timemachine, i could only find 2.52, not the older ones

 

3 minutes ago, OrionFOTL said:

Look up "Fair use".

european rules are different on that iirc... of course there's a fair use limit and i would first reach out if i actually needed some shots

 

but i can probably do on my own shots this time, saves me the headaches too

[PSUGuru]

Another indication that a PSU is group regulated is to look at the power distribution label. If the PSU says it can output a total a 600w but the 12v says it only outputs 400w, then that's an indication that it's group regulated.

Here's some images which hopefully provide additionally clarity to those that don't know. 

There are two sides to a PSU. Primary and Secondary. Won't go into details on the specifics here, people like OrionFTL and JonnyGuru are better able to explain that if they wish. The two coils boxed in red are located on the secondary side. 12v and 5v are regulated on the bigger coil and the small coil has 3.3v. Now a thing to consider here is that there is a secondary topology known as Dual Mag Amp, which has two magamp coils. Better than group regulation from a performance standpoint, but in general, it's not very efficient. I think the most you can achieve is bronze efficiency. Maybe silver. It can be easy to confused the two topologies. Now, sometimes, group regulation could use one coil. I've seen a few very old PSUs with just the one coil. (credit to JonnyGuru.com for this image.)

Below is a Corsair CX450, arguably the best budget PSU on the market for most areas. Boxed in red are the DC-DC converters. Now, this example shows the coils covered. But usually, the coils are exposed and mounted a daughter board(s). These regulate the minor rail outputs while the 12v is independently regulated. I think it's regulated with a switcher or something. Near the transformer. (If someone could confirm, that'd be nice. (credit to Tomshwardware.com for image)

This is to the best of knowledge, so I hope this gains some insight on what to look for.

[Guest]

I agree it's better to look for the DC to DC in a PSU to determine if it's not group regulated, rather than counting coils.

 

[LukeSavenije]

@jonnyGURU @OrionFOTL @PSUGuru @Vejnemojnen @Fasauceome @Oalei i did some changes according to suggestions, see if you're happy with the result or have any further suggestions to bring up

 

and for Fasauceome, i'll bring it into the group today if i can 

[Fasauceome]

Very nice indeed, thread improved.

 

Still, the meat of the topic should be addressed: "why group regulated power supplies are bad." You do explicitly say that they're old and we've got modern designs that are better, but old things aren't intrinsically bad. To my knowledge, it's bad because it forces the vrm components on your other parts like video card or motherboard to overcompensate due to bad power delivery, but I'd like to know if there's more to it.

[LukeSavenije]

9 minutes ago, Fasauceome said:

why group regulated power supplies are bad

because they force a rail out of atx spec and can't use modern sleep states, as said above... it's clear to me, but i could be wrong

[Fasauceome]

2 minutes ago, LukeSavenije said:

because they force a rail out of atx spec and can't use modern sleep states, as said above... it's clear to me, but i could be wrong

Think about someone who doesn't know anything about PSUs. They'll read that and say "so what," or "what does that mean," because like I said, these are not problems that you can see when you build a system and turn it on. It helps to say what the end result of going out of ATX spec does to your PC, and what failing those sleep states results in.

[LukeSavenije]

Just now, Fasauceome said:

Think about someone who doesn't know anything about PSUs. They'll read that and say "so what," or "what does that mean," because like I said, these are not problems that you can see when you build a system and turn it on. It helps to say what the end result of going out of ATX spec does to your PC, and what failing those sleep states results in.

ah... now it makes more sense what you meant

 

i'll see what i can make out of it later... another update i guess

[Fasauceome]

Just now, Tegos said:

I got one of those atm. Should I be rushing out to buy a new PSU and throw my current one in the trash?

Depends, what are you powering. Your sig?

[LukeSavenije]

Just now, Tegos said:

I got one of those atm. Should I be rushing out to buy a new PSU and throw my current one in the trash?

that's a bit extreme, as vs at least has UVP and actually is one of the few that meets c6/c7, just barely

 

but if you can replace it soon-ish with a good deal on a decent dc-dc, i would recommend you do

[Fasauceome]

3 minutes ago, Tegos said:

Yeah, that's what it's powering for now

Well, a moderate CPU like that and very moderate GPU are not likely to have big problems, like noted in the original post the best use for group reg units is for lower power draw hardware like this.

 

Like you mentioned, it's best to throw the baby out with the bathwater and just get a new PSU when you system upgrade.

[Guest]

14 minutes ago, Tegos said:

I got one of those atm. Should I be rushing out to buy a new PSU and throw my current one in the trash?

Having any problems now?  No?  Don't worry about it.