why the avx mechanism is different between z490 and x299

[Jiangv]

I have two setup, one is 10980xe on x299 motherboard, another is 10900kf on Z490,

I overclocked 10980xe to all cores 4.8G, avx offset 8, avx512 offset 20, for the 10900kf over clocked to all core 5.1G, avx offset 2.

when I testing with R20 benchmark, 10980xe will run on non-avx freq 4.8G at all cores, but when I testing 10900kf, it will downgrade to avx freq, which is all cores 4.9G,

the question is why it happens, why 10980xe not running avx freq when testing R20?

[Sebastian_M_Intel]

Hello Jiangv, 

Thank you for posting on the Intel® communities.   

We do not recommend nor support overclocking, we provide the tools and products for it but that is at each user's own risk. Altering clock frequency and/or voltage may (i) reduce system stability and useful life of the system and processor; (ii) cause the processor and other system components to fail; (iii) cause reductions in system performance; (iv) cause additional heat or other damage; and (v) affect system data integrity. Intel has not tested, and does not warranty, the operation of the processor beyond its specifications. 

I will recommend you to set the BIOS settings to their defaults and disable all the overclocking features -check with your motherboard manufacturer (OEM) for help- and then test the CPUs. Also, please provide the following (with default settings): 

1. Run the Intel® System Support Utility (Intel® SSU) and attach the report generated:  

• Open the application, check the "Everything" box, and click on "Scan" to see the system and device information. By default, Intel® SSU will take you to the "Summary View".   
• Click on the menu where it says "Summary" to change to "Detailed View".   
• To save your scan, click on "Next", then "Save".   
• Use the option under the reply window to attach the report to the thread (Drag and drop here or browse files to attach).  

2. Run the Intel® Processor Diagnostic Tool and send the results either in a screenshot or .txt file. To save the report, once the test is done, click on "File >> View Results File" and attach the .txt file to your reply. 

Regards, 

Sebastian M  

Intel Customer Support Technician 

[Jiangv]

Hi Sebastian

I dont think your answer is helping me.

I just want to know the avx mechanism between Z490 and X299, I believe the overclocking is not relevent.

can you share me more details about the avx?

[Sebastian_M_Intel]

Hello Jiangv,  

Please let me review your request internally. 

Once we have an update to share, we will post it on this thread. Kindly wait for a response.  

Regards,  

Sebastian M  

Intel Customer Support Technician  

[Sebastian_M_Intel]

Hello Jiangv,   

Thank you for waiting. 

On this processor's subforum, we can only provide information about what this technology does and the properties of the CPU. 

Intel® AVX is a 256-bit instruction set extension to Intel® SSE designed for applications that are Floating Point (FP) intensive. AVX improves performance due to wider vectors, new extensible syntax, and rich functionality. This results in higher performance and more efficient data management across applications. https://www.intel.com/content/www/us/en/support/articles/000005779/processors.html  

As you have questions regarding the AVX mechanisms, we have a dedicated forum for these inquiries, please post your question on Software Development Technologies > Intel ISA extensions: https://community.intel.com/t5/Intel-ISA-Extensions/bd-p/isa-extensions  

Regards,   

Sebastian M   

Intel Customer Support Technician  

[Sebastian_M_Intel]

Hello Jiangv,   

We hope that our previous suggestion guided you to the correct place. We will proceed to close this inquiry from our side.

If you have any additional questions, please submit a new thread and we will gladly assist you.

Regards,   

Sebastian M   

Intel Customer Support Technician