AM4 and power phases

[coffeemonster]

It's been a while since I've shopped for a decent motherboard. It seems to me there are more power phases on the AM4 line than I remember seeing on FM2+ and AM3+

Do the Ryzen chips need more phases for even moderate overclocking? or do we really even know yet?

they vary from 6 to 10 phases on the B350 range if my info is correct.

If all I want to do is lock a 1700 at 3.5 or 3.7Ghz would I necessarily need to get one of the 10 phase models or would the 6 phase work just fine?

 

[UsandThem]

It's been a while since I've shopped for a decent motherboard. It seems to me there are more power phases on the AM4 line than I remember seeing on FM2+ and AM3+

Do the Ryzen chips need more phases for even moderate overclocking? or do we really even know yet?

they vary from 6 to 10 phases on the B350 range if my info is correct.

If all I want to do is lock a 1700 at 3.5 or 3.7Ghz would I necessarily need to get one of the 10 phase models or would the 6 phase work just fine?

I'd say if you can wait for a couple weeks to allow time for the various reviews to start coming out, it probably would be the best. Since the first reviews were just published yesterday, it will take a little of time for people to get their boards and report back on their findings. A lot of people ended up not getting their CPU or motherboard on launch day due to delays from places like BH Photo and Amazon. There is just too much unknown at this time to really give you an accurate answer on that.

I know from reading the initial reviews overclocking was not good as anticipated, so there will need to be some BIOS updates and other fixes to know for sure where everything stands.

 

[Puffnstuff]

It's been a while since I've shopped for a decent motherboard. It seems to me there are more power phases on the AM4 line than I remember seeing on FM2+ and AM3+

Do the Ryzen chips need more phases for even moderate overclocking? or do we really even know yet?

they vary from 6 to 10 phases on the B350 range if my info is correct.

If all I want to do is lock a 1700 at 3.5 or 3.7Ghz would I necessarily need to get one of the 10 phase models or would the 6 phase work just fine?

Historically phasing is relational to stability so you have to decide on whether or not this is important to you and if it is how much are you willing to pay for it.

 

[coffeemonster]

thanks for the reply

I've been reading on various other forums. Seems these B350 boards are all very capable for moderate overclocks on Ryzen 8 cores.

Even the wraith spire that comes with the 1700 seems to be pretty decent for moderate overclocks

 

[Puffnstuff]

thanks for the reply

You are very welcome. Speaking for myself I tend to use motherboards with more than the minimum requirement for a given socket even though I'm not a hardcore overclocker.

 

[DrMrLordX]

Just an FYI but I'm hearing the Gigabyte Gaming 7 5 has a weak PWM (and no external clock generator). So if you're worried about VRMs, that may not be the board for you.

The Gaming 7 will probably be better.

 

[tcsenter]

Probably more to do with enthusiast or higher-end parts being launched first.

 

[Doom2pro]

AM4 has two power planes, one for the CPU stuff and one for the SOC (Think PCIe, USB, M.2, etc.. and GPU for future APUs).

Some high end x370 boards have a split VRM, like 8+4 (Crosshair Hero) and 6+4 (MSI XGAMING TITANIUM), the larger number is for CPU plane the smaller and second number is for the SOC Plane.

 

[unseenmorbidity]

AM4 has two power planes, one for the CPU stuff and one for the SOC (Think PCIe, USB, M.2, etc.. and GPU for future APUs).

Some high end x370 boards have a split VRM, like 8+4 (Crosshair Hero) and 6+4 (MSI XGAMING TITANIUM), the larger number is for CPU plane the smaller and second number is for the SOC Plane.

What do you think the Taichi is?

6+ 6 doubler + 4?

 

[VenomXTF]

Just an FYI but I'm hearing the Gigabyte Gaming 7 5 has a weak PWM (and no external clock generator). So if you're worried about VRMs, that may not be the board for you.

The Gaming 7 will probably be better.

What about the ASRock Taichi? I'm basically stuck deciding between the Gaming 5 or the Taichi.

 

[DrMrLordX]

What do you think the Taichi is?

6+ 6 doubler + 4?

If ASRock's AM3+ Extreme 9 is any indicator, there's a doubler in there somewhere. But I'm not sure. ASRock claims the board can handle 300W draw to the CPU socket, which is a bit crazy.

What about the ASRock Taichi? I'm basically stuck deciding between the Gaming 5 or the Taichi.

It's an interesting board, and I'm eyeballing it myself since Amazon has told me it could be 2 weeks before they even ship my C6H (while NewEgg will have it in 4 days).

See above, plus the Taichi has an external clockgen for people wanting to use the bclk OC trick.

 

[unseenmorbidity]

plus the Taichi has an external clockgen for people wanting to use the bclk OC trick.

What is this?

 

[DrMrLordX]

http://www.asrock.com/mb/AMD/X370 Taichi/

Hyper BCLK Engine II

An additional external base clock generator that supports PCIe frequency overclocking. It provides a wider range of frequencies and more precise clock waveforms, allowing any user to get most from their CPU investment with precise, stable overclocking.

What that really means is . . . well . . .

https://www.techpowerup.com/220703/...tors-to-circumvent-intel-non-k-bclk-oc-limits

Some platforms require an external clock generator to allow users to tweak bclk like in "the old days" such as s939, AM2, LGA1366, etc.

Boards like the Gaming 5 do not have an external clock generator, so you can not budge bclk at all.

 

[unseenmorbidity]

http://www.asrock.com/mb/AMD/X370 Taichi/

Hyper BCLK Engine II



What that really means is . . . well . . .

https://www.techpowerup.com/220703/...tors-to-circumvent-intel-non-k-bclk-oc-limits

Some platforms require an external clock generator to allow users to tweak bclk like in "the old days" such as s939, AM2, LGA1366, etc.

Boards like the Gaming 5 do not have an external clock generator, so you can not budge bclk at all.

That is interesting, but aren't the Ryzen chips fully unlocked?

PS: I haven't done AMD OC'ing.

 

[DrMrLordX]

They are. BUT! But. If you get stuck in OC Mode, you lose some power saving features and other . . . things.

Plus if you set memory speeds to anything higher than DDR4-2400, subtimings are loosened which can hurt memory performance, so you get more performance from setting DDR4-2400 in the UEFI and then raising bclk to increase memory speeds.

 

[tamz_msc]

Not all the phases are meant for the CPU - the extra ones are there for the APUs when they are released later in the year - for powering the GPU inside them.

 

[unseenmorbidity]

They are. BUT! But. If you get stuck in OC Mode, you lose some power saving features and other . . . things.

Plus if you set memory speeds to anything higher than DDR4-2400, subtimings are loosened which can hurt memory performance, so you get more performance from setting DDR4-2400 in the UEFI and then raising bclk to increase memory speeds.

Some info I found regarding this,

Overclocking the base clock (BCLK) on AM4 platform is possible, however generally not recommended. This is due to its frequency relations with other interfaces, such as the PCIe. Unlike with Intel's more recent CPUs, there is no asynchronous mode (straps / gears) available, which would allow stepping down the PCIe frequency at certain intervals. The PCIe frequency relation is fixed and therefore it increases at the same rate with the BCLK. Gen. 3 operation can generally be sustained up to ~107MHz frequency and higher speeds will usually require forcing the links to either Gen. 2 or to Gen. 1 modes.

motherboards have the external BCLK generator (you can't change BCLK without it).
Also I heard BCLK clock = PCIE clock (AM4 platform uses 100MHz BCLK as opposed to 200Mhz of previous AMD platforms, PCIE speed wasn't linked to BCLK in those) which can lead to many problems, from simple instability to data corruption.
Higher memory ratios are only available on a few motherboards and even on those they're very dodgy and unstable. Also ryzen runs very loose memory subtimings at higher ratios, defeating the point of higher frequency memory and sometimes causing instability not because the subtimings are too tight but quite frankly because they're too loose.
Overall to achieve these kits' advertised speeds you will need a high end motherboard with external clock generator (only ASUS C6H is validated by G.Skill at the moment - the board that is currently plagued by a BIOS issue that can randomly brick it), a ryzen sample that works fine at nearly 120MHz BCLK (I heard not everyone was able to reach that value, someone somewhere mentioned having issues with going past 107MHz, unfortunately I can't remember who) which also means that you need a good ryzen sample in general because manipulating BCLK or multiplier disables boost and XFR so unless you can achieve the boost/XFR speed on all cores you're losing single threaded performance.

 

[os2wiz]

It's been a while since I've shopped for a decent motherboard. It seems to me there are more power phases on the AM4 line than I remember seeing on FM2+ and AM3+

Do the Ryzen chips need more phases for even moderate overclocking? or do we really even know yet?

they vary from 6 to 10 phases on the B350 range if my info is correct.

If all I want to do is lock a 1700 at 3.5 or 3.7Ghz would I necessarily need to get one of the 10 phase models or would the 6 phase work just fine?

Actually Ryzen only requires 6x4 power phase for good overclocking of cpu and memory. There are those who believe otherwise since it would be very difficult for them to prove their case as the highest overclock without LN2 belongs to a board with 6x4 power phase the MSI X370 Xpower Titanium. I have one and the vrms never get too hot.