rickypicky5,
Although your test methodology is correct and your front-mounted radiator is optimal, as
Phaaze88 already pointed out, a 240mm AIO isn't enough for overclocking the 9900K; a 280, 360 or custom loop is instead recommended.
Firstly running Prime95 gives 10 to 12c higher then say Aida64 or a non synthetic benchmark or stress test. So if you want to test it out on full load then use a free benchmark app and those stressed cores will really be 68c I bet you ...
Turtle Rig,
As is the case with the vast majority users, you appear to share a few of their misconceptions which we need to clear up for the OP's benefit,
rickypicky5, as well as for our other forum members and visiting readers.
"Firstly" ... Prime95 Small FFTs (AVX disabled)
IS "full load". Moreover, considering the numerous environmental, hardware and software variables involved, I wouldn't "bet" on 68°C. Such numbers get flung around websites and forums like gorilla poo in a cage. Respectfully, without specifying ambient temperature, precise workload conditions and power consumption (just to mention a few), it's not possible to predict Core temperatures with any degree of accuracy.
"Full load" is a popular but
non-specific user term which could mean
anything, so it's important to be
very specific. Games, apps, streaming, rendering, transcoding and most utilities have partial,
fluctuating workloads with
fluctuating Core temperatures that are
not well suited for testing thermal performance.
“Stress tests" vary widely and can be characterized into two categories;
stability tests which are
fluctuating workloads, and
thermal tests which are
steady workloads. Prime95 Small FFTs
(AVX disabled) is ideally suited for testing thermal performance, because it conforms to Intel's Datasheets as a
steady 100% workload with
steady Core temperatures. No other non-proprietary utility can so closely replicate Intel's thermal test workload.
Utilities that don't
overload or
underload your processor will give you a valid thermal baseline. Here’s a comparison of utilities grouped as
thermal and
stability tests according to % of TDP, averaged across six processor Generations at stock settings rounded to the nearest 5%:
Although these tests range from
70% to 130% TDP workload, Windows Task Manager interprets every test as
100% CPU Utilization, which is processor resource activity,
not actual workload.
Core temperatures respond directly to Power consumption (Watts), which is driven by workload. Prime95 Small FFTs
(AVX disabled) provides a
steady 100% workload, even when TDP is exceeded by overclocking. If Core temperatures don't exceed
80°C, your CPU should run the most demanding
real-world workloads without overheating.
As you can see on the above scale, Prime95 (AVX enabled) imposes a
brutal 130% workload. However,
As per Intel’s Datasheets, TDP and Thermal Specifications are validated “without AVX” which is why we run Prime95 Small FFTs
without AVX for testing thermal performance. If OCCT's first CPU test, called "
OCCT", is configured for
Small Data Set and
No AVX, then it's a
steady 97% workload which is nearly identical to Prime95's Small FFTs without AVX.
The problem with AIDA64 is that it has 4 CPU related stress test selections (CPU, FPU, Cache, Memory) which have
15 possible combinations that yield
15 different workloads and
15 possible Core temperatures. The individual FPU test is about 115% TDP workload, the CPU/FPU combination is about 90%, all 4 tests combined is about 80% and the individual CPU test is only about 70%. All other AIDA64 test selections are fluctuating workloads which are suitable for
stability testing, but not for
thermal testing.
Shown below from left to right: Small FFTs, Blend, Linpack and IntelBurn Test. The
steady thermal signature of Small FFTs allows accurate measurements of Core temperatures, which is key for thermal testing so the CPU, cooler, socket, motherboard and voltage regulator modules (
VRM) can thermally stabilize.
... The chip can go to 90c and still work fine so yes you can try for a overclock of more then 4.7Ghz on all cores and what not. 🤷♀️😲👶☮👩🦲
Although "Throttle" temperature(Tj Max) for the 9900K is 100°C, the consensus among well informed and highly experienced reviewers, system builders and expert overclockers, as well as
Intel Engineers, is that it's prudent to observe a reasonable thermal margin below Throttle temperature for ultimate stability, performance and longevity. As such, here's the nominal operating range for Core temperature:
Core temperatures above 85°C are not recommended.
Core temperatures below 80°C are ideal.
Core temperatures increase and decrease with ambient (room) temperature, for which the International Standard for "normal" is 22°C or 72°F.
If you'd like to get up to speed on this topic, then read our
Intel CPU Temperature Guide 2020. It's a "Sticky" at the top of the CPUs Forum that's always available for everyone's benefit.
CT
Facebook
Twitter
Instagram