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Apex x299 avx offset voltage?

formula383
Level 7
Was wondering if someone can help me to locate the cpu avx voltage.

Voltages work proper until i set the avx offset then the voltage for the avx work load gets put back to 1.15vcore. If i lock voltages the avx voltage stays at 1.325vcore. however using locked mode i burn 100 watts at idle extra over adaptive mode. Any help would be appreciated thanks!
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cstkl1
Level 7
formula383 wrote:
Was wondering if someone can help me to locate the cpu avx voltage.

Voltages work proper until i set the avx offset then the voltage for the avx work load gets put back to 1.15vcore. If i lock voltages the avx voltage stays at 1.325vcore. however using locked mode i burn 100 watts at idle extra over adaptive mode. Any help would be appreciated thanks!


theres no diff voltage per state.( 512/avx2/non)

manual = fix voltage for all state*
offset/adaptive = based on vid table ( cpu multiplier to a predetermined voltage)*

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formula383
Level 7
Ok then, i have problem with the offset not functioning correctly. If i use no avx offset the voltage works normally under avx work load. but if i use a offset on the avx multiplier then the voltage go's down to its default 1.15vcore... How can i fix?

formula383 wrote:
Ok then, i have problem with the offset not functioning correctly. If i use no avx offset the voltage works normally under avx work load. but if i use a offset on the avx multiplier then the voltage go's down to its default 1.15vcore... How can i fix?


i find the best combination is running fixed manual voltage with cstate. it allows low power consumption during idle even at fixed voltage.*

example of my 24/7 is 1.184 @4.7ghz offset -2 avx -4 avx 512.
stability test for me was
8hours realbench 2.43 for 4.7ghz (non avx)
8hours realbench 2.54 i think at 4.5ghz ( avx offset 2) ( u will see it flux between 4.7-4.5 depending on the test it runs)
6 hours of encoding using one version of x264 that takes advantage of avx 512. of course it is not a superstable test as full load on avx512 at this point will exceed 100c. ( flux between 4.5-4.3)

hci memtest for 4000% ( around 20hours) to weed out any 1-2errors .

*hope this helps ya
*

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formula383
Level 7
Thank you for your help and C states do lower the clocks and seems to help greatly with power consumption. However the voltage remains the same at all times. While this i better for setting avx offset, it is still less than ideal. Also setting C states lowers performance by a noticeable amount. where as adaptive voltage does not. I find very hard to believe a top end motherboard bios does not have this feature??

So either i am forced to run lower default clock and use no avx offset or run extreme offset of say 8 to 9, or just burn full power all the time, and run higher temps than what i would like to as i can not tune the voltages for avx work. Less than ideal to say the least. 😞

Silent_Scone
Super Moderator
As a general rule, most CPU I've worked with on this platform seem to work well with a 3 and 5 offset for AVX and AVX512 respectively from the stable non-AVX clock, but each CPU may need tuning manually to find the best AVX stability. This is something Silicon Lottery in the US have also discovered so there must be a ring of truth to it. Just need to see what works best for your own sample.
13900KS / 8000 CAS36 / ROG APEX Z790 / ROG TUF RTX 4090

kathampy
Level 7
Everyone OCs X299 wrong. The SVID of bad cores at maximum frequency on these CPUs is ~1.35 V, and your Adaptive voltage will be ignored if it is below the SVID. Thus if you overclock, you are actually doing it at stock voltage and it will be unstable. The correct way to OC is to use Adaptive + Offset mode, or plain Adaptive / Override mode with a voltage above the highest SVID.

There is a lot of misinformation regarding Adaptive + Offset mode, especially when combined with AVX offsets.
Adaptive voltage raises only the minimum voltage while Turbo is active (any frequency above base such as AVX offsets, not just the maximum). This way the CPU can idle at stock voltage (which is below the minimum configurable Adaptive voltage of 1.2 V).
Offset voltage is added at all frequencies, including idle.

The formula is:
Adaptive voltage + Offset = Minimum stable AVX-2 & AVX-512 frequency voltage
SVID + Offset = Minimum stable non-AVX frequency voltage

The SVID table is not designed for AVX loads. For example:
45x non-AVX has a stable SVID of 1.200 V.
45x AVX-512 OC has the same SVID of 1.200 V but will crash. It needs 1.225 V.
49x non-AVX OC has an SVID of 1.350 V but will crash. It needs 1.375 V.
All of these voltages are for the worst core with the highest voltage requirement.

Adaptive voltage = 1.200 V and Offset = +0.025 V will result in a stable OC.
You can also set Adaptive / Override voltage = 1.375 V which is stable but overvolts the AVX frequency heavily, as well as the good cores at the non-AVX frequency which have stable SVIDs below 1.375 V.

First stabilize the AVX frequency with just Adaptive voltage. Don’t use Offset yet as it increases the idle voltage. Then stabilize the non-AVX frequency using Offset if required. If you increase Offset, reduce Adaptive voltage accordingly.