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Question i7 4770k Haswell Prime95 26.6 vs 29.xx

Hundenabbe

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Jan 18, 2014
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Hi, I’ve been trying to overclock my i7 4770k on the newest version of Prime but couldn’t get it stable on 4.3 at 1.250volts, temps were really high on my Corsair H100i pro. I installed the 26.6 version instead and now the overclock is stable and doesn’t rise above 75c in temps, How come?

Questions:

1) Does it have to do with Haswell and AVX running unrealistic temps?

2) Is a Haswell chip even worth using with the newest Prime version?

3) Is Prime26.6 okay to use instead of Prime29.xx? (not sure what the newest version is called)

4) What programs and such uses AVX so I can stay clear of trouble.
 
1) Yes, AVX will give unrealistic temps on Haswell.

2) Not unless you have extreme cooling solution.

3) Yes, just use v26.6

4) Assassin's Creed Odyssey uses AVX, but it should still be okay. If your CPU doesn't support AVX, then you can't run the game.

Prime95 combined with AVX is the unrealistic part. But if you're cooling solution can handle that, then it can handle anything.
 
P95 26.6 small fft uses a 100% consistent workload. It also uses the same instruction sets in the cpu that games (for the most part) use. So it's a good indicator of exactly where the cpu will be at under the worst possible gaming conditions.
AVX, AVX2, AVX-512 are specialized instructions used almost totally by some professional type content creation and other such apps. Outside of the odd game like AC Oddessy you'll not see much if any AVX, even rarely AVX2 and never AVX-512, but those instructions (amongst others) are included in the cpus to cover all bases, including professional usage.

So for most ppl AVX testing is not only useless, it's unwarranted. Not to say you shouldn't, but it's pointless to base max temps on an instruction that'll drive the cpu upto 130% overload temps when nothing you do will hit 100% as gaming usually won't reach over @ 70%.
 
1) Yes, AVX will give unrealistic temps on Haswell.

2) Not unless you have extreme cooling solution.

3) Yes, just use v26.6

4) Assassin's Creed Odyssey uses AVX, but it should still be okay. If your CPU doesn't support AVX, then you can't run the game.

Prime95 combined with AVX is the unrealistic part. But if you're cooling solution can handle that, then it can handle anything.
I've heard that Battlefield V is using avx, I'm soon getting my rtx 2060 and that's why I'm overclocking to squeeze extra fps when playing BFV, the division 2 and far cry new dawn. Should I worry?
 
P95 26.6 small fft uses a 100% consistent workload. It also uses the same instruction sets in the cpu that games (for the most part) use. So it's a good indicator of exactly where the cpu will be at under the worst possible gaming conditions.
AVX, AVX2, AVX-512 are specialized instructions used almost totally by some professional type content creation and other such apps. Outside of the odd game like AC Oddessy you'll not see much if any AVX, even rarely AVX2 and never AVX-512, but those instructions (amongst others) are included in the cpus to cover all bases, including professional usage.

So for most ppl AVX testing is not only useless, it's unwarranted. Not to say you shouldn't, but it's pointless to base max temps on an instruction that'll drive the cpu upto 130% overload temps when nothing you do will hit 100% as gaming usually won't reach over @ 70%.
Do you think BFV, The Division 2 and Far Cry New Dawn will use avx?
 
No, I don't think you should worry about it, at least not too much. If you have to you can just tweak the AVX offset. Just keep an eye on temps and use your judgement.

*I don't know about all these new games and AVX. I did just find that AC Oddyssey was updated to support non-AVX CPUs.
View: https://www.youtube.com/watch?v=Vv9FKBIpZkU
Wow, Ubisoft is not very good at making their customers happy haha
 
... you can just tweak the AVX offset ...

MrN1ce9uy,

Since Hundenabbe has a 4770K, his 4th Generation motherboards does not include any AVX offset features. AVX offset was introduced with 6th Generation and later motherboards to compensate for the adverse affects that AVX codes can impose on stability and Core temperatures.

4th Generation users who are into rendering or transcoding can implement a work-around, which is to configure separate BIOS profiles; one for gaming and another for a -200 to -300MHz downclock to accommodate AVX apps. As a reboot is required it's a bit cumbersome, but at least there's a solution.

Regardless, the use of AVX codes in games can be taken in stride, as it's nowhere near as CPU intensive as it is in AVX specific apps, and especially in utilities such as Prime95 27.7 through the latest version 29.4.

Hundenabbe,

As per Intel’s Datasheets, TDP and Thermal Specifications are validatedwithout AVX”. Intel tests their processors using a steady-state 100% TDP non-AVX workload to validate Thermal Specifications. Prime95 version 26.6 Small FFT’s is consistent with Intel’s Datasheets. There are no other utilities which can so closely replicate Intel's load test parameters.

See Section 11 - Thermal Test Basics: Intel Temperature Guide - https://forums.tomshardware.com/threads/intel-temperature-guide.1488337/

CT 😎
 
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MrN1ce9uy,

Since Hundenabbe has a 4770K, his 4th Generation motherboards does not include any AVX offset features. AVX offset was introduced with 6th Generation and later motherboards to compensate for the adverse affects that AVX codes can impose on stability and Core temperatures.

4th Generation users who are into rendering or transcoding can implement a work-around, which is to configure separate BIOS profiles; one for gaming and another for a -200 to -300MHz downclock to accommodate AVX apps. As a reboot is required it's a bit cumbersome, but at least there's a solution.

Regardless, the use of AVX codes in games can be taken in stride, as it's nowhere near as CPU intensive as it is in AVX specific apps, and especially in utilities such as Prime95 27.7 through the latest version 29.4.

Hundenabbe,

As per Intel’s Datasheets, TDP and Thermal Specifications are validatedwithout AVX”. Intel tests their processors using a steady-state 100% TDP non-AVX workload to validate Thermal Specifications. Prime95 version 26.6 Small FFT’s is consistent with Intel’s Datasheets. There are no other utilities which can so closely replicate Intel's load test parameters.

See Section 11 - Thermal Test Basics: Intel Temperature Guide - https://forums.tomshardware.com/threads/intel-temperature-guide.1488337/

CT 😎
😉