Precision Boost 2 and Precision Boost Overdrive

[Relentless81]

Can someone please clarify this for me it's driving me nuts

I'm looking at a 2600X, I'm not manually OCing, I'm thinking pairing it with an MSI Tomahawk or Pro Carbon but read that PBO doesn't work too well on these boards.

Have I got the following right

PB2 is a default feature for all core boost so a 2600X will all core boost to 4.0ghz with default settings, no messing around it's just standard

PBO is an additional feature that needs to be enabled that pushes the ranges of PB2 even further over and above 4.0ghz in the case of the example of a 2600X

So basically I wouldn't care for PBO because it's a form of OCing?

I also read that PBO was 2nd gen Threadripper only but there's loads of talk about it working on X series Ryzen 2 CPU too

If anyone who understands this better than me be could clarify I would appreciate it

Thanks

 

[kitfit1]

PB2 or XFR 2 to give it it's proper name is the bog standard method used by the CPU to boost both it's all core clock and it's single core clock. The ability to do this is embedded into the CPU microde and will be the same for all motherboards.
PBO is very similar in that it boosts all core clocks and single core clocks. It does have to be enabled in the bios though because it's not using the microde embeded into the CPU. PBO and how high it clocks is completely dependent on CPU temps, how strong the mobo's VRM's are and how much Vcore it has to use.

I've always used PBO with my CH6 along with PE level 4, it gives me an all core boost to 4.25Ghz and a single core boost to 4.35Ghz. Vcore under stress testing goes to 1.39v and temps vary rarely go above 60c.

 

[opethdisciple]

Its very confusing.

You are correct in your understanding of PBO and PB2.

I would say the way it's meant to work is with a 2000 series CPU and an x470.

The waters get muddy when you run a 2000 series CPU on x370. Support is there but it can be partial or non-existent.

As an example. My 2700x on my 370 board. At one point Asus released a BIOS that allowed us to enable the feature. (that was the only option. On or off)

However 6 months later they removed it. Can't really say it did much tho. Didn't seem to boost speeds (all core) over 4Ghz which is what it does with it turned off.

 

[kitfit1]

Its very confusing.

You are correct in your understanding of PBO and PB2.

I would say the way it's meant to work is with a 2000 series CPU and an x470.

The waters get muddy when you run a 2000 series CPU on x370. Support is there but it can be partial or non-existent.

As an example. My 2700x on my 370 board. At one point Asus released a BIOS that allowed us to enable the feature. (that was the only option. On or off)

However 6 months later they removed it. Can't really say it did much tho. Didn't seem to boost speeds (all core) over 4Ghz which is what it does with it turned off.

I think you'll find that PBO along with PE (Performance Enhancer) has only ever worked to it's full potential on the CH6, which is why i kept mine and didn't change to an X470. As i said, the mobo needs strong VRM's and good cooling to get the best result.

 

[opethdisciple]

I think you'll find that PBO along with PE (Performance Enhancer) has only ever worked to it's full potential on the CH6, which is why i kept mine and didn't change to an X470. As i said, the mobo needs strong VRM's and good cooling to get the best result.

On my Prime Pro x370 there never was any Performance Enhancer settings. PBO has been removed completely from the bios now however.

 

[Relentless81]

Thanks for the info, as long I was right in thinking PB2 is default and 4ghz out of the box I'm not really bothered about PBO

I'm not sure I understand why the MSI boards are stated to not support PBO very well though, will this affect PB2 on an MSI board?

Depending on what you read it's only the MSI boards that struggle with it

 

[KungFuSpaghetti]

Just leave it all auto, enabling pbo on my taichi does increase the clock speeds a bit, but the vcore went higher than I was comfortable with. Difference in performance in gaming was negligible.

 

[Relentless81]

Just leave it all auto, enabling pbo on my taichi does increase the clock speeds a bit, but the vcore went higher than I was comfortable with. Difference in performance in gaming was negligible.

But your still getting the full use of PB2 right? What I'm asking is, in the case of the MSI Pro Carbon and Tomahawk, if they aren't recommend to use with PBO which I've read multiple times, how does it affect PB2 on those boards? Maybe they don't hold all core boost for quite as long as some other boards

 

[Murphy]

FWIW Precision Boost Overdrive can be thought of as doing the same thing people do when they increase the thermal & power targets on GPUs, you're basically giving PB2/XFR2 more headroom.

For example, PB2/XFR2 will keep increasing the clock speed of individual cores until it reaches either X degrees or Y voltage, PBO basically increase those limits by a certain amount (i can't remember by how much)

 

[Orange Nexus]

Just leave it all auto, enabling pbo on my taichi does increase the clock speeds a bit, but the vcore went higher than I was comfortable with. Difference in performance in gaming was negligible.

Aren't you able to set a negative offset on the vcore? Like -0.1v?

Not mine but saw this in another forum.https://imgur.com/a/ZGOyduX

 

[Relentless81]

FWIW Precision Boost Overdrive can be thought of as doing the same thing people do when they increase the thermal & power targets on GPUs, you're basically giving PB2/XFR2 more headroom.

For example, PB2/XFR2 will keep increasing the clock speed of individual cores until it reaches either X degrees or Y voltage, PBO basically increase those limits by a certain amount (i can't remember by how much)

Yeah but the way I've started to think of it is PB2/XFR2 is capped, PBO just kind of basically removes that cap

Negative Offset, I think thats whats missing from the MSI boards, is that just an OC feature and doesnt affect PB2?

 

[tamzzy]

I'm thinking pairing it with an MSI Tomahawk or Pro Carbon but read that PBO doesn't work too well on these boards.

just to clear up any misconceptions.
you were right to say that MSI wasn't good for PBO - if you said this in november 2018. As of december 2018, they've released their latest bios which does support negative offset voltages.
this negative offset voltage was the only thing holding back their motherboards - as their VRM implementation is the best for the B450 series.
hence, there's no reason now, not to get the MSI boards, except for petty reasons, such as "oooh i don't like MSI"

 

[tamzzy]

PB2 or XFR 2 to give it it's proper name

not quite.
PB2 and XFR2 are two totally independent things.

PB2 is the newer implementation of...you guessed it...PB1, which gives finer granularity over core clocks depending on how many cores are loaded. in contrast, PB1 only had this implementation for the first 2 cores.

(source: https://www.anandtech.com/show/12625/amd-second-generation-ryzen-7-2700x-2700-ryzen-5-2600x-2600/5)

XFR 2 is temperature dependent, ie, if your CPU is cool enough, then your all core speeds will be boosted, but vcore stays the same

PB2 and XFR2 is implemented in CPU microcode, so is independent of the mobo

PBO is different from PB2 and XFR2 in that it requires mobo compatibility (ie, not all boards support it). PBO takes into account temperature and voltages and boosts voltage for a higher clockspeed, if both temp and voltage are not at its limits.
the issue with PBO is that it tends to give too much voltage, hence the CPU will hit its temperature limit faster - therefore if one uses PBO, one will preferably require a negative offset (anywhere between 0.05v to 0.1v) to hit the max PBO boost clocks.
(see my previous post for why MSI wasn't the best - but now is)

shamelessly stolen image, but i think explains PB2, XFR2, PBO very well.

source: http://www.xanxogaming.com/reviews/gigabyte/b450-aorus-pro-wifi-english/4/

 

[Murphy]

Just to add to the pretty pictures.

(Sauce)

 

[Relentless81]

Cheers for the informative posts everyone, there is lot of misinformation on the internet I think people get PBO and PB2 confused

I'm not interested in PBO, I simply want the best board that will maintain the PB2 and XFR2 for the longest but also use the 3200 XMP of my RAM

My previous B350 Gigabyte ran the XMP no issues what so ever so I'm tempted by another gigabyte board but the MSI seems better specced, any thoughts on this?

just to clear up any misconceptions.
you were right to say that MSI wasn't good for PBO - if you said this in november 2018. As of december 2018, they've released their latest bios which does support negative offset voltages.
this negative offset voltage was the only thing holding back their motherboards - as their VRM implementation is the best for the B450 series.
hence, there's no reason now, not to get the MSI boards, except for petty reasons, such as "oooh i don't like MSI"

How is the RMA process for MSI compared to Gigabyte?

 

[tamzzy]

I'm not interested in PBO, I simply want the best board that will maintain the PB2 and XFR2 for the longest

the board with the best VRM

XMP no issues

that's RAM, not CPU
also, gigabyte boards are a bit more picky with ram

I'm tempted by another gigabyte board but the MSI seems better specced, any thoughts on this?

you already have my thoughts on this issue, MSI wins this round, hands down

How is the RMA process for MSI compared to Gigabyte?

MSI RMA is in netherlands IIRC, GB is in england.
how this will work after brexit? dunno.

 

[HRL]

Just leave it all auto, enabling pbo on my taichi does increase the clock speeds a bit, but the vcore went higher than I was comfortable with. Difference in performance in gaming was negligible.

I use PBO on my 2700X, along with a bit of a BCLK increase. What is a comfortable vcore on these chips as even at stock it would top 1.5v when boosting briefly using XFR2?

 

[tamzzy]

What is a comfortable vcore on these chips as even at stock it would top 1.5v when boosting briefly using XFR2?

1.4v
hence using negative offset

 

[tamzzy]

Just to add to the pretty pictures.

shows PB1/XFR1, but nice comparison to PB2/XFR2 though

 

[HRL]

1.4v
hence using negative offset

I'll have a play around tonight and see if I can reduce it a bit. Getting all cores boosting to 4.5Ghz isn't too shabby though.