With AMD's latest Ryzen Threadripper 3990X 64-core behemoth to be releases on the 7th of February, ASUS has unveiled an updated version of its flagship ROG Zenith II Extreme motherboard. The new ASUS ROG Zenith II Extreme Alpha model is designed to make the most of the AMD Ryzen Threadripper 3990X processor with a newly updated power delivery while keeping the same ROG aesthetic and feature set of the previous model.

At the launch of AMD's TRX40 chipset for the third generation of Ryzen Threadripper 3000 processors, we reviewed the ASUS ROG Zenith II Extreme motherboard which supports the Threadripper 3990X out of the box, and delivers a high-quality feature set and competitive performance, for an $850 price tag. The ASUS ROG Zenith II Extreme Alpha retains the same aesthetics, the same feature set, and one would struggle to see the differences on the surface between both models.

The major difference comes on the power delivery, with a solid 16-phase configuration for the CPU with sixteen Infineon TDA21490 90 A power stages. This replaces the previous Infineon TDA21472 power stages which are rated for 70 A, albeit still very high end in the grand scheme of things. It is likely that ASUS is retaining its ASP1405I PWM controller, which is virtually identical to the Infineon IR35201 in terms of specifications. 

The inclusion of 90 A power stages over a 70 A variation is likely to allow more current to be deployed, which should help with overclocking. Although this is mainly something extreme overclockers will be interested in, the original ASUS ROG Zenith II Extreme model is more than capable of handling the 64-core AMD Ryzen Threadripper 3990X processor out of the box. We've also heard some crazy overclocking power numbers on the 3990X, which we're looking forward to verifying.

While the ASUS ROG Zenith II Extreme Alpha is likely to be released around the same time as the AMD Ryzen Threadripper 3990X 64-core processor on February 7th, the official release date for this model is unknown. The original ROG Zenith II Extreme has an MSRP of $850, and we expect the new Alpha version to cost slightly more, but no pricing information has been made available at this time.

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  • Hul8 - Wednesday, January 29, 2020 - link

    Again, not any kind of 16-phase!

    Why do tech media continue to spout these lies about ASUS's boards? Claims that ASUS themselves very deliberately aren't making, because saying such would be false advertising.

    While it has 16 *power stages*, teaming them into pairs instead of using doublers still results in just 8 phases - the two components run in parallel and in the same phase.
  • Hul8 - Wednesday, January 29, 2020 - link

    "Phase" in computer power delivery uses the regular meaning of the word, not some special "computer" variant. Here it refers to the phase of AC power thru a circuit. https://en.wikipedia.org/wiki/Phase_(waves)

    In order to facilitate efficient adjustment of power usage and maintain required output voltage regardless of current, the incoming 12V DC power is modulated by periodically cutting the signal (at over 100 kHz), creating a (more or less) square waveform in each phase.

    The signals from multiple phases (whose phases are evenly spaced) are combined and filtererd to produce a constant DC output with the desired voltage.

    A theoretical example:
    If input voltage is 12V and 3V output is required, in the combined signal (pre-filtering), you'd have 12V 25% of the time and 0V 75% of the time. Filtering averages this out and you get 3V DC. In the real world any inefficiencies have to be taken into account.

    A phase doubler splits the waves from its input alternately among the outputs, resulting in each output having different phase.

    Teaming on the other hand just doubles (or triples/quadruples) the capacity of the components in the same phase.
  • Hul8 - Wednesday, January 29, 2020 - link

    And note that the % of the time of 12V versus 0V is done with PWM; altering the length of time for which the 12V is held.
  • Unix_SU - Friday, February 14, 2020 - link

    I am interested in this motherboard, I see it is the new Alpha TRX40.

    Originally I assumed the AMD 3970X would be compatible, however I just checked the ASUS website compatibility list and it is only showing 3990x as compatible, but then in the description it says supports TRX40 up to 64 cores, really confused whether this will support my AMD 3970x or not? ?

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