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The Exiled · 04.10.2022., 10:57

AMD Ryzen 9 7950X Cooling Requirements & Thermal Throttling

Citiraj:

The frenzy around the 95°C load temperature of the processor had gotten so bad that some predicted that cheap air coolers could "start fires." This clearly won't happen as our testing confirms. The Wraith Spire is a 95 W-capable cooler that probably costs AMD $10-15 to bundle with each PIB package. It's a piece of aluminium with a fan—as basic as stock coolers can get. When paired with the 7950X, the cooler is able to keep the processor away from damage or overheating and runs 100% stable all day. Things get interesting with the Noctua NH-U14S, which is among the best single-tower fin-stack coolers out there. With its stock NF-A15 140 mm fan in place, the NH-U14S has a manufacturer-rated cooling capacity of 165 W, but let's round it to exactly match the 170 W TDP of the 7950X.

In single-threaded workloads, the NH-U14S is almost able to match the most powerful cooler in our comparison, a 420 mm AIO with a Zen MCM-optimized cold-plate offset. The biggest problem is probably psychological. For years we have been trained that "95°C is bad". This is no longer true. 95°C is the new 65°C. The fact that the CPU will always run at around 95°C will make it difficult to quantify a cooler's capability though. Imagine—you're spending $200 on an AIO and you're going from 95°C to 95°C—you'd be disappointed. What you might not be noticing immediately is that with Zen 4 you will now get higher performance in return, automatically, without doing anything, that will be your benefit of upgrading—more perf, not lower temps. Overall this great news for Zen 4 buyers and owners: just stop worrying about the heatsink, buy anything reasonably decent, it doesn't have to be an AIO, and you'll be fine.

Izvor: TechPowerUp

Citiraj:

AMD Ryzen 7950X: Impact of Precision Boost Overdrive (PBO) on Thermals and Content Creation Performance

Citiraj:

On the whole, we were a bit surprised at how little of an impact these overclock settings made. All of our photo and video editing benchmarks saw virtually no difference in performance, with the largest variance being just 3%, which is within the margin of error for this kind of real world testing. Even Cinebench single core and V-Ray rendering in CPU mode was no different with any of the settings or coolers. Basically, this means that the biggest impact on performance these overclock settings make tends to be on highly threaded workloads. And, even then, the difference is only about 10% at most. On the whole, it is amazing how much disabling PBO and CPB reduces the CPU temperature. On heavy sustained loads like Cinebench multi core, we went from 95C to just 65C - that is a 30C drop in CPU temperature! Even relatively lighter loads like Photoshop went from temperatures ranging from 60-80C with PBO/CPB enabled to just ~42C with them off. Others like Premiere Pro, After Effects, and DaVinci Resolve were frequently hitting 95C with PBO/CPB, and dropped to 40-62C with then disabled. As a reminder, these are workloads that saw no difference in performance, yet the 7950X CPU is as much as 30C, or even 40C, cooler with PBO/CPB disabled.

In most of the workloads we tested, it is very clear that using Precision Boost Overdrive (PBO) and Core Performance Boost (CPB) is not worth it.

Izvor: Puget Systems

Ryzen 9 7950X performance to power limit scaling