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post #1 of 5 (permalink) Old 03-28-2012, 07:49 PM - Thread Starter
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Just wondering. What is the best?

Just as an example: my board has 10 Phase Digital PWM vs the other model FTW 200 which has 12 Phase Analogue PWM.

10 digital or 12 analogue?

I see some boards nowadays with 16+ power phase. Are these analogue or digital? How can you verify this?

From what I've read digital is the best but it costs more. Thus, you can often see analogue with higher number of power phase (VRM I guess). The digital is more precise than the analogue but if you have more analogue VRM you should have less current fluctuation resulting in a steadier current?
So, yea wondering. I guess the precision of digital VRM is good when extreme cooling.

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post #2 of 5 (permalink) Old 03-29-2012, 09:40 AM
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the difference is very small, while digital is more precise, analog is faster and has better transient response. What I tell you to do is to please go and find out what VRM components are being used in the phase. The PWM is 1 chip, and it controls the VRM. Analog and digital PWMs control the same VRM hardware, but that hardware differs per board. The PWM controls the VRM, so it is always an analog VRM, but the PWM can differ in many ways. It also depend which maker of the digital or analog.

PWM isn't so important either, the implementation by the manufacture is as well, aso while gigabyte and asus does excellent with digital now, asrock does terrible with it, and switched back to analog to either save money or increase phase count.

You can have 16 phase digital PWM controlled VRMs, but 12 phase is more common.

the MOSFETs are extreme important, then the chokes and the capacitors. the choke and mosfets will determine how much current can flow as well as some of the ripple and efficiency, and the caps will determine the ripple and transient response. when i say determine i mean limit, these are teh weak points in the system for those things. MOSFETs don't have much to do with ripple, but inductors do.

I wrote this a wahile ago, it tells the difference between analog and digital: http://sinhardware.com/index.php/vrm-articles/101-digital-vs-analog-pwms

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post #3 of 5 (permalink) Old 03-30-2012, 07:15 AM - Thread Starter
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Well thanks, I guess you answered my question thumb.gif +rep

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post #4 of 5 (permalink) Old 03-30-2012, 11:33 AM
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also mate, watch out for lying companies. MSI and ASRock are just plain liars, they put in their marketing materials that they use digital PWMs for Z77, but the truth is asrock is lying 100%, they actually changed from a digital Chil controller to a pure analog Intersil controller, thus rendering their PWM analog and not digital.

MSI likes to say hybrid-digital, but the truth is they never said this pre X79, and they are using the same PWM, they are just lieing, as gigabyte switched to digital now everyone wants to go digital, but they can't because of price and quantity of the chips available for sale. Also digital doesn't allow good phase doubling techniques, they only result in doubled driver oputputs when it comes to digital PWM scheme doublers, so you can't do more than 1 integrated power stage per phase, unless IR makes a new doubler which can, which I think they might. Otherwise they ill have a true 8 or 6 phase PWM with doubled up phases, so 1 phase would have the number of power stages as two, and add a second inductor and it looks like 2 phases but is actually `1 phase.

But who can protect you? reviewers should, however their knowledge of board components is that of a dolphin's knowledge of the universe and space. THey are oblivious. However I review boards, and I don't lie about what type of components are used, i will even link datasheets when needed, however just never take any reveiwer's word for it, always check for yourself, datasheets on everything are available if you look hard enough.

I saw one reviewer take MSI's hybrid digital claim, and say it was fully digital, reviewer even wrote fully digital, i wanted to kill him, and i felt like giving him a curb job for his utter ignorance he deserves not to review motherboards but more importantly shouldn't even own a computer he is so ignorant he might think a Microsoft owns Apple or some outrageous thing like that.

BTW why can MSI claim hybrid digital, well because of SVID. SVID is a digital 3-wire bus which allows the CPU to communicate its requested voltage to the PWM which then controls the phases, however as soon as it enters any analog PWM such as those made by uPI(MSI uses uPI) and those made by Intersil (ASRock uses intersil for Z77 and beyond) it is immediately converted to an analog signal through a analog to digital converter(ADC).

Good luck mate, it really doesn't make much difference if analog or digital is used, analog is a bit easier to implement, more straightforward, and faster, but digital gives more user control, gives better transient load control, and is more precise period.

I guess since asus dropped asrock(asus is selling their 30% of share of asrock), now asrock can't use the 8 phase digital PWM anymore, that is my guess. BTW the fact that asus owns 1/3 of pegatron, that should confirm what I have been saying all a lon that no one wants to observe.

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post #5 of 5 (permalink) Old 03-30-2012, 02:02 PM
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BTw current can be equal in both VRMs, just the digital will be more precise and the analog more quick, but they can use the same exact mosfets, inductors, and capacitors. However newer digital PWMs are faster, and newer analog PWMs are more precise.

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