4+1 vs. 8+2(8+1) Phase Power Design

[Sparky]

Try overclock voltages in bios, see if there vdroop or instability.
Some mobo can't take high vcore for long benching session.

http://img503.imageshack.us/img503/8...shot046uw2.jpg

Ouch.

[gOtVoltage]

Try overclock voltages in bios, see if there vdroop or instability.
Some mobo can't take high vcore for long benching session.

your not alone ,,

Ive made many bagels using a model 770/790gx (ultra self cleaning disposable convection oven) smoke signals when the clean cycle is done

[gOtVoltage]

Bringing this old thread back to life. What about the 8+1 Designs ? The cost between the 8+2 and 8+1 are alot, i could buy the Phenom 955 and a Asus 8+! board for $309 allowing me money to buy a 4890 and memory, whereas the 8+2 design i would be short . How would this affect overclocking tho vs a 8+2 board ?

If you get a 8+1 make shure it has Ramsinks or at least some type of cooling if there is not a heatpipe from the get go.



Ive pushed 4+1 and @1.65volts it isnt pretty compared to 8+1 mobos.




For $100 - $120 there are several new 8+2 mobos that are fantastic. Most of them will handle 1.55v-1.70v fairly easy and qiute stable under preshure.

Now Under $80 you can find some Nice older 8+1 will handle about the same up to 1.6v with a High TDp Oc. You need to have the Fets properly cooled. The 4+1's can still Pop with high volts even with w/B cooling.

Im surprized i have not Popped the TA770 with 1.65v when the 9950 was @3.5ghz. That Mobo Hurt my ears it Screamed so loud

The Ones that dont come with a heappipe just need to be improvised with Ram sSinks or a Fan/Sink cooler of some sort.

The Open Box Mobos EGG,, Are insane right now. Most Mobos will just need a CD or manual . Most the Ones ive ever recieved were exactly that an Open Box with Everything inside

[chew*]

None of these are true 8 + 2 phases......its a gimmick...

[gOtVoltage]

None of these are true 8 + 2 phases......its a gimmick...

There still 4 and or 6 but just name them 8+1 or 8+2 what ever correct.

I mean if you count the fets chokes , at least that what it seems to be anyway.

[chew*]

yes they are 4 and 6 phases, no true 8 phases on any of them....I would just pay more attention to the quality of the components used.

[Mechromancer]

yes they are 4 and 6 phases, no true 8 phases on any of them....I would just pay more attention to the quality of the components used.

You mean to say my Asus M3A79-T Deluxe which clearly states on the front of the box that is it "8+2 Phase Power Design" is only a 4 phase?! That makes me quite angry at Asus.



So this is a blatant lie?

[G.Foyle]

There seems to be a lot of confusion about ASUS 8+2 power circuitry.
Both Crosshair 3 and M4A79T-Deluxe use L6740 PWM controller made by ST Micro.
It's a 4+1 phase controller, which means power regulation is done in 4 phases for core voltage and in 1 phase for NB voltage. ASUS uses double inductors for each phase to split the load to more components and thus increase longevity and decrease temps. It's not a true 8 phase regulation, the same as for example Rampage II Extreme PWM being a 8-phase, double inductor design, not a 16-phase PWM.


Whether it is a blatant lie depends on what does "phase" mean for you. ASUS and Gigabyte seem to think that inductor = phase, but rest of the world knows that "phase" is "one part or portion in recurring or serial activities or occurrences logically connected within a greater process, often resulting in an output or a change." (Wikipedia). Phase is not something that exists on motherboard PCB, it's a parameter of the voltage control process. So for most people, yes, ASUS and Gigabyte and many other manufacturers lie about their PWM designs.

EDIT: The same design is used on M3A79-T Deluxe.

[chew*]

Yep good info man.....

I believe the gigabyte is a 6 phase......but they go about 6 phase a diff way.....

[xdan]

Hello guys, i'm not to expert in phase power design, can one of us please tell me how man phases for CPU have the board in the picture?
5 CPU+ 1chipset ( or4 4+2?)? The board is ASROCK A790GMH/128. I'm planning to buy one, it's PWM seems to be solid even though it has no cooling..
And. i have heard that Asrock MB overvolts the voltage a bit, quite strange...
Opinions if this 90$ can hold a X3 720 at 1.5v?

[chew*]

Judging by the components used I would not plan on breaking any records....An 8 pin input at the PWM would not hurt......seems they only used 4pin....they are likely overvolting to comnpensate for vdroop....

[xdan]

Judging by the components used I would not plan on breaking any records

I'm not planning to break any records , i'm planning a decent overclock 3.7-3.8GHZ no more than 1.5v..
Actually from a 90$ Mb it will be quite good...

[G.Foyle]

Gigabyte 790FXT-UD5P has similar 4+1 phase, double inductor design with Intersil controller (I cant remember the exact model)

[chew*]

Ahh that must be the intels they run 6 phase on then.....

[Tomasis]

I'm not planning to break any records , i'm planning a decent overclock 3.7-3.8GHZ no more than 1.5v..
Actually from a 90$ Mb it will be quite good...

maybe 1.45v is possible.. biostar am2+ can not go far above 1.45v Asrock and Biostar pwm looks similiar. 720be 3,7ghz is doable on v1.425 there you have hope

[nr4]

xdan i'm not sure, but at a first sight of the motherboard i would say that is a 4+1 phase pwm.
The 6th "phase" is for the 790GX chipset.

I would also say that the cpu VRM is pretty weak because it has only 2 mosfets on a phase. Nowadays a good motherboard has 3 or 4 mosfets (4 on ASUS motherboards ex: M3N78PRO motherboard).

[xdan]

would say that is a 4+1 phase pwm.
The 6th "phase" is for the 790GX chipset.

+1 for what ?,if the six is for chipset? memory has it's PWM.

Nowadays a good motherboard has 3 or 4 mosfets (4 on ASUS motherboards ex: M3N78PRO motherboard).

That has no Amd 790GX/FX/XT chipset and neither SB 750 or 710.
This Asrock is the cheap 790GX(SIDE PORT MEMORY)+SB 750(ACC) i've found.
For what i want the cheaper Asus mb is 30$ fo for 4 mosfets it doesn't worth. And Biostar MB i can't buy because i can't find near bye.

[nr4]

No, you didn't understand:

The CPU VRM is composed of:
-4 phases for the CPU(cores) (4 coils + 8 mosfets)
-1 phase for the memory controller embedded into the cpu(1 coil + 2 mosfets)

The A790GMH/128MB is the chipset of the motherboard with diverse functions. It's vrm is that 6th pair of 1 coil + 2 mosfets.

I reffered to ASUS M3N78PRO as having a solid CPU VRM for it's price and an example of a motherboard with 4 mosfets on phase.
For OC AMD790XX chipset + SB750 is the best option.

[G.Foyle]

+1 for what ?,if the six is for chipset? memory has it's PWM.

Most PWM controllers for AMD platforms have 4 phase regulation for core voltage and 1 phase regulation for NB and L3 cache (uncore) - that's what 4+1 means.

EDIT: ninja'd by nr4

[Entropicity]

So much talk and none about MSI's DrMos?

MSI is one of the top tier companies that have refused to join the phase marketing game. How would a 5 phase DrMos fare vs the Asus/Giga monster phase power?

[xdan]

Ok, i understood, thank you very much nr4 and xoqolatl for explications, anyway i will still buy that board because i'm making an ultra performance budget system -220$ i mean the A790GMH/128-90$, an X2 550(instead of x3 720)-103$ may be i get@quad?!, a 2GB DDR2 1066 kit of memory-30$. And i want that video on board because i'm waiting the 4770 to restock, or the 4730 to appear .....
Still if that it's not hapening soon i will buy an 4850 at 110$....

[chew*]

So much talk and none about MSI's DrMos?

MSI is one of the top tier companies that have refused to join the phase marketing game. How would a 5 phase DrMos fare vs the Asus/Giga monster phase power?

According to initial reports and tests it has blown up ( under extreme testing )......however not being one to follow the crowd I will test it myself with proper insulation and a bios that works right this time......I personally have had no issues pushing it hard on air or water.....

[Entropicity]

According to initial reports and tests it has blown up......however not being one to follow the crowd I will test it myself with proper insulation and a bios that works right this time......

OUCH! I better be careful with mine then. I guess it should be ok for "normal" overclocking.

One thing I do notice is it DOES run cooler.

[G.Foyle]

Dr. MOS is, in short, a technology where a pair of mosfets (high & low) and a mosfet driver are integrated into one circuit. Instead of three (driver, mosfet low, mosfet up) you have one. They have nothing to do with phase count, but MSI says they run cooler and output less ripple. MSI is not the only company that uses integrated mosfets; Gigabyte has them too, for example on GA770T-UD3P.

[Tomasis]

So much talk and none about MSI's DrMos?

MSI is one of the top tier companies that have refused to join the phase marketing game. How would a 5 phase DrMos fare vs the Asus/Giga monster phase power?

probably phase 5 means 4+1 after all..