Sensible AVX2 and AVX512 negative offset values for a i9 [email protected]?

[RavenLunatic]

Not sure where I should post this since it’s about CPU, Overclocking & cooling, and Motherboards so I will just post it in General. Mods feel free to move it if needed.

I recently moved from a custom water cooling set up with 2 560mm radiators to an ARCTIC Liquid Freezer II 420 CLC as my custom cooling setup was getting old (6 years without servicing), and I was concerned about the possibility of failure and leaks as a result.

Understandably my temps now are a little higher than they were, but when stressing my CPU with programmes that use AVX2 or AVX512 the core temperatures go up to 108 degrees Celsius and does not throttle (TjMax is 110 degrees Celsius). I don’t recall what the temperatures where like running AVX software under custom water-cooling setup, but it must have been low enough for me not to be concerned about.

In normal usage the temperatures are fine, idling at 30 degrees Celsius and up to 45 degrees Celsius when running games and normal programs with the occasional spike at 65 degrees Celsius. My motherboard settings for negative offset are set to auto, but this does not seem to be dropping the frequency and is therefore allowing AVX programmes to run all 18 cores @4.5 GHz!

108 degrees Celsius seems a little hot even if its within Intel specifications. I cannot find any recommended values for AVX2 and AVX512 negative offset on Intel’s or ASUS websites. Should I just ignore AVX programmes and carry on regardless? If not, what temperature should I aim at when setting the negative offset manually? Base clock is 2.6GHz, I am thinking that would be the safest negative offset setting to use.

System specs
Intel Core i9 7980XE @ 4.5GHz, (de-lidded and liquid metal pasted)
128GB Corsair @ 2666MHz (16-18-18-35)
ASUS WS X299 PRO_SE
24GB GeForce RTX 4090 (ZOTAC International)
1.5GB INTEL Optane SSDPE21D015TA/ 7.5TB (16*500GB SSD RAID 5)

 

[Tetras]

Do you set all AVX or just AVX-512?

512 is not used in games, so far as I know, but I don't think you want ALL AVX running at 2.6 Ghz because you'd lose loads of FPS in AVX games if you run at such a low clock speed.

 

[RavenLunatic]

I don't know. I was running Cinebench when I noticed the temperature go over 100 degrees I assume that is running AVX512. I have read before that some people consider AVX512 is a power virus lol. So much so Intel removed the feature in later chips! I thought at first it was the cooler so I removed it and re-applied the paste and no change.

E: Cinebench R20 does use AVX512 when available. I was using R23 so it definitely uses it.

 

[RavenLunatic]

For some reason the AVX offset is not working
I changed the AVX512 to 10 rebooted ran Cinebench R23 and the clock speed did not drop. Tried again this time setting the AVX offset to 6 and that did not work either. still hitting 108 degrees Celsius. Is there some other setting that I am missing?

 

[Tetras]

For some reason the AVX offset is not working
I changed the AVX512 to 10 rebooted ran Cinebench R23 and the clock speed did not drop. Tried again this time setting the AVX offset to 6 and that did not work either. still hitting 108 degrees Celsius. Is there some other setting that I am missing?

Hmm, my google results confuse me, but it looks like Cinebench R23 does not use AVX-512, but Cinebench 2024 does, though not greatly.

 

[RavenLunatic]

You are correct Cinebench R23 is running AVX2. I had just assumed that since R20 did have AVX-512 they would keep it going.

 

[Tetras]

You are correct Cinebench R23 is running AVX2. I had just assumed that since R20 did have AVX-512 they would keep it going.

maybe Intel complained when they fused it off with 12th gen

 

[RavenLunatic]

I have changed the AVX2 offset back to default of 3 and leaving the AVX-512 at 10.

I tried changing the CPU Core Ratio settings I had it set originally to Sync All Cores which gave me 108 degrees boosting to just under 4.5GHz.

Changing that to By Core usage temperatures dropped to 60 degrees but CPU would not boost past 4GHz and only momentarily, mostly averaging 3.4GHz for everything.

Finally Setting it to Specific core core resulted in the temperature hitting 97 degrees with the Max boost hitting 4.2GHz

Downloaded Cinebench 2024 and the Boost clock was at 4.2Ghz again and the temperature did not go above 91 degrees most of the time it was in the 80s.

Everything was configured to auto settings.

I think I am happy with By Specific core setting, anything less than 100 degrees counts as acceptable. Given that it is the worst-case scenario my CPU would ever likely face.