標題: [主機板] RYZEN 超頻電壓問題 [打印本頁]

---

作者: KK83512    時間: 2017-8-30 14:21     標題: RYZEN 超頻電壓問題

本帖最後由 KK83512 於 2017-8-30 15:45 編輯

剛入手左R7 1700x + Asus B350-F+240水冷
可能唔係太熟AMD底板關係，要用到1.38v先勉強超到3.9Ghz (用Offset mode)
我用HWInfo睇返的電壓數字會發現,只要我一用Prime95等STRESS TEST軟件去到Full Load時,
個底板個Vcore會即時上到1.41-1.42v附近,但CPU Package VDD個電壓會相反跌到去1.33-1.34v
我睇過文章話咁係正常,通常會用Load Line Calibration去平衡返,
但我已經試過調整Vcore Load Line Calibration,但似乎無野可以阻止個CPU Package VDD下跌咁多
究竟以上情況係正常,定係我底板供電有問題呢?

---

作者: 98a    時間: 2017-8-30 15:33

本帖最後由 98a 於 2017-8-30 21:34 編輯

Mobo CPU Voltage = the voltage given by mosfet
CPU VDD = current CPU voltage

CPU Voltage - CPU VDD = vdorp
LLC is to try minimize the vdorp, which will push harder on the mosfet. LLC↑, mobo Vcore↓

However, to stabilize the vdrop, LLC is not the only variant. Mosfet quality , circuit design will also affect the efficiency of LLC. For most of the B350 mobo, they are not using high-end VRM. Basically, B350-F Gaming is a RGB+ROG-based BIOS of B350-Plus. Nothing had changed on the design and component which help to improve OC ability.

I won't say your broad is defected. Also, LLC level should not be over Lv3.

VRM info:
https://www.hardwareluxx.de/comm ... -liste-1155146.html

---

作者: KK83512    時間: 2017-8-30 21:02

本帖最後由 KK83512 於 2017-8-30 22:21 編輯

回覆 2# 98a

Thx for the link, which is quite informative.
From what I see, Asus X370 Gaming is using the same Mosfet as that of Crosshair VI Extreme which is supposed to the new flagship of X370's line. Isn't it a great deal for stable O/C if I dun want to spend necessary amount of money on a Crosshair.

Yet, even with X370, it seems to me that the potential extra speed that I could get from a new board will be fairly limited, as many of the o/c'er are getting 4.0-4.1 Ghz with reasonable Vcore given.
Looks like there is nothing I can do now to push further unless with a new board.

---

作者: 98a    時間: 2017-8-30 21:34



The marjority of Ryzen can reactch 3.9~4.0 ghz with 1.4v ~ 1.45v

The OC-ability of X370 and B350 are similar. Not really suggest people to change there broad just for OC. I would rather wait for 3rd generation of ZEN. It may be have more hard room for OC.

I always avoid "Gaming" mobo as it most likely will be just a gimmick.

---

作者: jason060188    時間: 2017-8-31 11:38


你個情況我都研究左好耐，發現CPU溫度越低，vdd個電壓就越高，待機時CPU溫度30度左右時vdd個電壓會接近CPU電壓，但一full load CPU溫度上到60度時，vdd電壓就會跌(比如我行3.85ghz, BIOS set CPU  電壓1.33v，行p95時CPU電壓會上到1.363v，溫度60度，vdd就會跌到1.288v 至 1.293v，如果CPU溫度高過65度vdd電壓就會跌到1.27v 以下，咁電腦就會重啟，所以溫度對超頻幾重要，之餘點解會咁，有Ching話因為溫度高電阻高！

via HKEPC Reader for Android

---

作者: rockie520    時間: 2017-8-31 11:54

i used B350 asus , before , and i oc to 3.9 (v1.35 and never can made it to v1.38) still have fps dropped issue with some retarded game. so i changed to c6h the electricity supply to CPu can pump up to 1.5v... with auto.... and i oc to 4.0 which has no issue with the suddenly FPS drop issue......

---

作者: 98a    時間: 2017-8-31 12:00



   
温度↑ = 電阻↑

假設 VRM 輸出電壓一樣 (1.3v)，

idle: CPU 30c, mobo 42c。由於溫度較低，電阻較低。由 VRM 經過 circuit 時電阻較低，所以最終到達 CPU 時會流失較少電壓, i.e. CPU VDD=1.25v

Full load: 60C CPU &Mobo。由於温度較高，電阻增加。由 VRM 經過 circuit 時損失較多，所以最終 CPU 只係接收到 1.2v


所以 full load 時 VRM 亦會提高電壓。

via HKEPC Ionic Reader v1.7.0 - Android

---

作者: 98a    時間: 2017-8-31 12:04

回覆 6# rockie520

You mean you are using 4.0 with AUTO voltage?

I suggest you apply the same value on both board to verify whether it is luck or mobo issue

---

作者: rockie520    時間: 2017-8-31 12:06

本帖最後由 rockie520 於 2017-8-31 12:08 編輯

mobo issue , cuz b350 cannot use high Voltage....   but c6h auto voltage is too high.... i think

now i set it to 1.358 and Oc 3.75   since i do not trust my diy watercool . i dont have balls to oc 4.0 with high temperature water ...

---

作者: 98a    時間: 2017-8-31 12:16



Nope. B350-Plus still can supply 1.4v.

In BIOS, if the Vcore is reported as 1.2V, you can +0.16v in offset mode which in total 1.36v.

---

作者: rockie520    時間: 2017-8-31 12:26

回覆 10# 98a

i can't with asus b350 plus Asus . it's offset can't more than 0.xxx something which i forgot

thats why i pissed off and switch to c6h

---

作者: 勁爆小朋友    時間: 2017-8-31 15:41



I am pretty sure you can alter the vddcr voltage in BIOS of b350plus to 1.4v using offset mode. Default voltage is 1.23750v. By selecting offset mode, mode sign "+", then you can input the offset voltage amount to achieve the desire voltage. E.g. for 1.4v, you only need to input 0.1625. Therefore you are right about the offset cannot go any higher than 0.xxxv because the max voltage input you can have is 0.2v (which is over AMD's recommended voltage anyway, giving you 1.23750+0.2= 1.4375v).

No doubt c6h is a better motherboard, sure you will like it over B350plus. But it looks like you mis-interpreted how B350plus BIOS works, which the board itself is already quite capable to achieve your desire voltage.

---

作者: KK83512    時間: 2017-8-31 17:59

本帖最後由 KK83512 於 2017-8-31 18:02 編輯

The Vcore adjustment (offset) method on Asus B350-F is really pissing me off. The so-called default voltage is frustrating so much, if you have a failed boot resulting from aggressive O/c setting.

I noted that when the boot is failed, the default vcore may increased according to the multiplier I entered (Auto voltage may be applied). For example, if multiplier is set to be 39, the vcore will become way over 1.375v, in my case, it is 1.4v-ish, plus the offset + I previously added. The actual voltage being supplies will be way over the sky.

That's why I have to increase the Vcore to a higher voltage first and then reduce only one increment at a time to prevent a fail reboot.

---

作者: 勁爆小朋友    時間: 2017-8-31 18:25



Your mentioned behavior sound strange. Usually when the machine failed to boot (normally after 3 attampts), the bios will reset itself to the manufacturer default, which has auto vddcr and default core clock enabled. This default setting would ensure the machine to boot flawlessly. I believe all motherboard would have the same settings to prevent over voltage and ultimately bricked the motherboard caused by not able to lower the voltage.

If your b350-f has the problem you mentied, it is either a faulty sample or a bios update might cure the issue. Nonetheless you are now on a working mitherboard, no so much to worry about anymore. I still believe your previous experience is a rare particular case only.

---

作者: 98a    時間: 2017-8-31 18:30



   
It is normal. After OC fail, it will boot from BIOS recovery mode which actually use the default settings。There should be "-" sign which allow you to subtract the voltage.

That also I won't recommend ppl to get B350 for OC unless it is on a tight budget. I really hate using offset mode.

via HKEPC Ionic Reader v1.7.0 - Android

---

作者: 勁爆小朋友    時間: 2017-8-31 19:16




"-" indicates negative offset, which is use to lower the voltage from the standard 1.23750v. I don't think that is useful to solve the over-voltage issue from boot-fails he mentioned.

Well, as long as he is happy with C6H now, that's all matters. I would like to own a high end motherboard like that too, but considering the price tag it carries, I would rather pay 1/3 of the price for the not far off B350plus, which I have been able to overclock to 3.925GHz with.