how can I find out what Xeon CPUs have FIVR hardware?

[blian]

our current system makes use of the Xeon D-1559 CPUs which have a FIVR (fully integrated voltage regulator).  we have had issues with long boot delay due to waiting for the de-assertion of a FIVR FAULT.  I can't find any information on if the D-1700 or D-2700 series CPUs also make use of this hardware.  The assumption is yes since it aids in reducing power consumption and is typically the goal of the D series CPUs.  

if anyone has insight on this or a pointer to some datasheet or block diagram to help confirm the presence or lack thereof FIVR hardware, that would be greatly appreciated and help us in resolving our customer's concern(s)

[Jaime_Lizarme]

Hi  @blian 

Thank you for contacting the Intel Embedded Community.

Yes, I can confirm that the Xeon D1500 Series have FIVR capability. Please refer to Intel Xeon D1500 Datasheet, Volume 3 of 4. RDC document 544042.

In order to get the information you need an RDC account would be required; so to get access to this you need to have a Resource and Design Center (RDC) privileged account. 

 The RDC Account Support form is the channel to process your account update process by filling out the form stated on the following website:

 https://www.intel.com/content/www/us/en/forms/support/my-intel-sign-on-support.html

 You should use a business email address to evade any inconvenience. Please avoid the free email provider's address (such as the provided by Hotmail, Gmail, Yahoo, or others).

 Best regards,

Jaime L.

Intel Customer

[Diego_INTEL]

Hello @blian,

Thank you for contacting Intel Embedded Community.

Yes, D-1700 and D-2700 uses FIVR.

You may check the following documents, but a Premier account is required to get access to them.

#618610 - Intel® Xeon® D-2700 and D-2800 Processor Families External Design Specification (EDS), Volume 1: Architecture

#622027 - Idaville HCC Platform Design Guide (PDG)

Best regards,

@Diego_INTEL 

[blian]

Diego, thank you very much for this confirmation, this is a great help to our team.  

is there any chance you could also inform me on this wrt the D-1800 and D-2800.  I assume from the documentation referenced here, that those CPUs are also utilizing FIVR hardware. 

we are also looking at another model of SBC which uses the Intel® Xeon® SP 6238T, does this CPU utilize FIVR hardware?  My initial thoughts are no, the D series CPUs focus on power efficiency, while the SP series focuses on performance.  FIVR provides more control on power regulation to conserve energy, but my understanding is that the FIVR hardware being on chip would generate its own heat load, which in turn affects performance by limiting thermal overhead of the CPU and would lead to throttling the performance of the CPU.   Given the design ideologies, I went ahead and told our customer that the D series would likely have FIVR hardware while the SP should not.  Please help me confirm this.  

I will go ahead and see if I can get this RDC account for future use in understanding what features are or aren't available.  we aren't an integrator of intel hardware, but buy of the shelf products that have been making use of these CPUs, and needed more information directly from the source.

[Diego_INTEL]

Hello @blian,

You are very welcome.

You are correct, the D series indeed use FIVR.

I was checking Cascade Lake documentation, that is the Intel® Xeon® SP 6238T, I'm seeing that it uses only IVR.

Best regards,

@Diego_INTEL 

[blian]

Diego, 

Thank you for that information, again this has been very helpful in us understanding what CPU(s) will fit our system's requirements. 

I requested access to the documentation asking for an RDC account, I was told: 

Hello Brandon,

Thank you for your interest in accessing the Resource and Documentation Center.

Intel periodically adjusts the visibility of its content to ensure enhanced security and scalability across its platform. Unfortunately, we are unable assist you further without Developer Zone Premier (DZP) access and an Intel account owner. Alternatively, you may reach out to one of Intel’s Authorized Distributors in your country or region, who can assist you with your documentation needs.

We appreciate your understanding and cooperation in this matter. We sincerely apologize for any inconvenience this may have caused. Please be informed that I will now proceed to close this case

Thank you for your cooperation and understanding. 

Best regards,

Michael Jethro C.

Intel Customer Support Associate.

So I don't think I will be getting more information looking there unless anything can be done from here in assisting with access.  

But with this answer I do now have another question, and I'm curious what the difference between FIVR and IVR are.  a quick google search tells me that FIVR is done on the CPU die and regulates more closely to the CPU allowing for finely tuned regulation.  IVR is typically somewhere on the substrate but not on the die, and does less, but exactly what rails or areas would be interesting to know.  like I assume both deal with CPU core voltage, but what about cache, IO, etc? This may be tougher to answer and could be on a case by case basis I would assume, but I figure it might be nice to get some general idea on core differences between FIVR and IVR. 

Thanks again, 

Brandon Lian

[Diego_INTEL]

Hello @blian,

I have found this public datasheet regarding the Ice Lake SP, it may be of some help:

https://www.intel.com/content/www/us/en/content-details/732800/3rd-gen-intel-xeon-scalable-processor-codename-ice-lake-sp-datasheet-volume-one-electrical.html?DocID=732800

2.1 Integrated Voltage Regulation
The VccIN platform voltage regulator powers integrated voltage regulators in the processor. Due to this integration, the processor has one main voltage rail (VCCIN) and voltage rails for the memory interface (VCCD0123, VCCD4567 - one for each 4 memory channel pairs). The VCCIN motherboard voltage rail will supply the integrated voltage regulators which in turn, will regulate to the appropriate voltages for the cores, cache, and/or system agents. This integration allows the processor to better control on-die voltages to optimize for both performance and power savings. The processor VCCIN rail will remain a VID-based voltage with a loadline similar to the core voltage rail (called VCC) in previous processors. In addition to the above, the processor has voltage rails VCCIO for I/O, VCCSA for the System Agent, VCIO_ANA and VCC_1P8 for PCIe Gen4 and VCC33 for PIROM.

For the Xeon D series I think all of them needs the a Premier account like the #631107 - Intel® Xeon® D-2700 and D-2800 Processor Families External Design Specification (EDS), Volume 3: Electrical, but there are more details regarding the FIVR.

Best regards,

@Diego_INTEL