{"id":116282,"date":"2022-09-19T20:30:38","date_gmt":"2022-09-19T18:30:38","guid":{"rendered":"https:\/\/www.hwcooling.net\/?p=116282\/"},"modified":"2022-09-19T20:33:06","modified_gmt":"2022-09-19T18:33:06","slug":"zen-4-has-a-thermal-boost-too-5-85-ghz-needs-temp-under-50-c","status":"publish","type":"post","link":"https:\/\/www.hwcooling.net\/en\/zen-4-has-a-thermal-boost-too-5-85-ghz-needs-temp-under-50-c\/","title":{"rendered":"Zen 4 has a thermal boost, too. 5.85 GHz only at sub 50 \u00b0C temps"},"content":{"rendered":"

It is often commented on that Intel processors (like the upcoming Raptor Lake) have many different boost modes with various conditions<\/a>, for example the temperature-dependent Thermal Velocity Boost. But it turns out that the Ryzen 7000s have something similar. According to unofficial information the top Ryzen 9 7950X model will also reach its maximum frequency only at low temperatures \u2013 impractically low, even.<\/p>\n

This information was reported by the WCCFtech website. They allegedly got confirmation from AMD that Ryzen 9 7950X will again have an actual maximum clock frequency higher than the 5.7 GHz listed in the specs. Again, this will be like in the 5000 generation, where for example the Ryzen 9 5950X has a real maximum 150 MHz higher than its officially specified boost<\/a>. For the Ryzen 9 7950X, this means that while the official maximum boost is just 5.70 GHz, in reality the processor can opportunistically go higher, up to 5850 MHz.<\/p>\n

This is not an overclocking, but rather a standard stock boost behavior. WCCFtech’s report confirms that the earlier reports of 7950X being able to boost to 5.85 GHz, which is a number that has been previously leaking unofficially<\/a>. But this extra clock speed is not guaranteed, the processor might only reach it in a fraction of loads, or only for a short time. The real catch is that with Ryzen 7000 it will probably be much more rare or harder to reach this higher clock speed on a regular basis, while on the Ryzen 9 5950X, it isn’t really uncommon to see it.<\/p>\n

According to WCCFtech, the processor can only reach 5.85 GHz on one core at a time, so it really is a “single-threaded turbo” in the true sense of the word. Naturally, we are talking about a preferred cores, i.e. the same principle as in Intel Turbo Boost Max 3.0 (AMD has been using extra clocks on preferred cores since Ryzen 3000 Matisse).<\/p>\n

The bigger and most important hurdle, however, is that the bonus 150 MHz will be temperature-dependent, which is in turn similar to Intel’s Thermal Velocity Boost. AMD apparently implemented a temperature condition for boosting on the Ryzen 3000<\/a>, but to be honest, we actually don’t know about this trait existing on the Ryzen 5000. However, the Ryzen 7000s do have this temperature-dependent boost \u2013 according to WCCFtech, the Ryzen 9 7950X can only go to 5.85 GHz if the silicon temperature is below 50 \u00b0C. This is supposedly information given directly from AMD.<\/p>\n

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AMD Ryzen 9 7950X processor specifications (source: AMD, via: AnandTech)<\/figcaption><\/figure>\n

This is a very low temperature, especially since the small 5nm Ryzen 7000 chiplets will be difficult to cool<\/a>. Even if you start with the CPU cooled down after a long period of being idle, even a single-core load will probably push the die above 50\u00b0C in no time. Thus, the 5.85GHz boost will be very short-lived in practice. If the processor is 50\u00b0C or higher, it will supposedly always boost “only” to the nominal 5.70 GHz given in the official specs. That’s not too bad, it would be worse if at higher temperatures the clock speed is below this promised level by the specs.<\/p>\n

For comparison, Raptor Lake and other Intel processors have 70 \u00b0C as a criterion for temperature-based boost, which gives much more room and the potential for practical benefit is naturally higher (Intel also includes this temperature bonus in the officially declared specifications though, unlike AMD). Keeping the Ryzen 9 7950X below 50\u00b0C will probably be difficult to achieve, it’s probably only possible with very powerful liquid cooling systems, or some sort of sub-ambient cooling technology (using chilled water or thermoelectric elements, see the Intel Cryo Cooling Technology<\/a> from recent past).<\/p>\n

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AMD Ryzen 7000 processors for socket AM5 (source: AnandTech)<\/figcaption><\/figure>\n

4,9\u20135,1 GHz all-core boost?<\/h3>\n

WCCFtech also writes that the boost for all cores is 5.1 GHz as maximum, but again, it probably depends on the temperature. At higher temps (with “worse” cooling, whatever that means) it could probably be closer to just 4.90\u20135.05 GHz. But in this case, we might not be talking about a completely hard immutable requirement. Until now, AMD hasn’t been setting any official all-core boost ceilings, the company just lets CPUs run as high as allowed by current limits, wattage limits, and maybe other physical factors allowed. So this claimed maximum for multi-threaded workloads is perhaps more of a typical empirically observed value than a hard obligatory specification for the CPU.<\/p>\n

Read more: AMD Ryzen 7000 officially: four models and specifications. Prices are better than expected<\/a><\/b><\/p>\n

So it looks like ultimately TSMC’s 5nm process and AMD’s architecture won’t reach higher clock speeds in practice than Intel’s 7nm process and the Raptor Cove\/Raptor Lake core. The Core i9-13900K is only 5.80GHz on paper<\/a> instead of the 5.85GHz of the Ryzen 9 7950X, but in practice, it’s likely to achieve this clock consistencly on a regular basis. And in any case, Intel will eventually release a 6.0GHz Core i9-13900KS model, which will settle this debate for good.<\/p>\n

Read more: Intel: Raptor Lake processors will reach 6 GHz. Core i9-13900KS confirmed?<\/a><\/b><\/p>\n

In the end, however, it doesn’t really matter exactly what clock speed the processor runs at, but what the performance will be. Hopefully, the performance will still be sufficiently close even if you don’t meet the less than 50 degrees condition due to using just a “normal” cooling (by which we mean “just” a high-end air cooler or a powerful AIO liquid cooler as opposed to some industrial chiller). We should find out in the next two weeks \u2013 Ryzen 7000s will start selling on 9\/27, and reviews will probably come out around that time as well.<\/p>\n

Source: WCCFtech<\/a><\/i><\/p>\n

English translation and edit by Jozef Dud\u00e1\u0161<\/em><\/p>\n