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How does 16 core Ryzen 9 3950X have the same TDP as 12 core Ryzen 9 3900X (105W)? It even has higher max boost frequency. Is it just because of lower base frequ
by shmerl 7y ago
How does 16 core Ryzen 9 3950X have the same TDP as 12 core Ryzen 9 3900X (105W)? It even has higher max boost frequency. Is it just because of lower base frequency?
* https://www.amd.com/en/products/cpu/amd-ryzen-9-3900x https://www.amd.com/en/products/cpu/amd-ryzen-9-3900x
* https://www.amd.com/en/products/cpu/amd-ryzen-9-3950x https://www.amd.com/en/products/cpu/amd-ryzen-9-3950x
- eightysixfour 7y agoIt may boost to a higher frequency but lower number of cores to have the same TDP.
- fabian2k 7y agoTDP doesn't tell you what the actual power consumption in practice will be. It is defined in some weird ways (different between manufacturers), and generally not intuitive. I would recommend to avoid trying to read too much into the TDP, wait for actual measurements of power consumption. My understanding is that typically the TDP is designed to fit to the base clock of the processor, and doesn't necessarily include the amount of power necessary to achieve the boost clocks.
- paol 7y agoAnandtech do a deep dive on how Intel calculate TDP numbers [0]. It's complicated (and completely different from AMD, so never try to compare numbers). [0] https://www.anandtech.com/show/13544/why-intel-processors-draw-more-power-than-expected-tdp-turbo https://www.anandtech.com/show/13544/why-intel-processors-dr...
- shmerl 7y agoInteresting, thanks! From that article, Intel's TDP is roughly equal to the power draw during full load on base frequency. How does AMD define it then? Also, what about GPUs TDP?
- paol 7y agoI've read some in-depth analysis of AMD's calculation somewhere too, but I forget where. I do remember that the TDP numbers on AMD are closer to maximum power draw. Never investigated GPUs. One way to find out would be to trawl Anandtech reviews and collect TDP and measured power draw numbers, they always take measurements.
- deleted 7y ago[deleted]
- ComputerGuru 7y agoYes, but he's not comparing TDP across manufacturers but rather across products from the same manufacturer (and generation).
- ksec 7y agoIt is just different "class" of CPU power usage and cooling, not their actual Power usage. So if you have a 105W cooling system both CPU should be fine. This is different to Intel's TDP which meant Typical Design Power, i.e Power usage when running in base frequency, in reality they run quite a lot higher.
- thisisnico 7y agoI thought TDP was Thermal Design Power?
- magila 7y agoBoost frequency is not related to TDP. Just because a processor says it can hit a maximum boost of 4.7 GHz doesn't mean it can do that with all cores active and stay within the TDP. It may not even be close. Base frequency is what is tied to TDP, hence the 300 MHz drop for the 16c model.
- masklinn 7y ago> How does 16 core Ryzen 9 3950X have the same TDP as 12 core Ryzen 9 3900X (105W)? Binning? There's variation in yields, the better parts might get classified as 3950X, the lesser ones get 4 cores disabled and a 3900X branding.
- deleted 7y ago[deleted]
- 292355744930110 7y agoLook at the Ryzen 7 3700X and 3800X. They are both 8 core parts with similar clock speeds but one is 65W and one in 105W.
- Kurtz79 7y ago3700X looks amazing at 65W for that price, can't wait for release.
- tracker1 7y agoMost likely much better binning.
- zbc 7y agoTDP is the maximum thermal power in watts that gets generated as waste heat that needs to be removed. A processor can consume 50 watts, but produce 100 watt waste heat, another processor can consume 400 watts and produce 100 watts of heat. Both have 100w TDP, but one consumes 150w, the other 500w. This is why TDP doesn’t tell the full picture. Because Ryzen 2 is manufactured on 7nm, it’s extremely efficient in that it doesn’t convert its energy into waste heat. Both 3900X and 3950X are designed to produce no more than 100 watts of heat. But of course, that doesn’t say how much current they actually draw under full load. That specification is the key and is very hard to find. When these chips are released, you will likely see reviews that measure the total system power, that is the power CPU draws plus PSU inefficiencies, VRM inefficiencies, motherboard component inefficiencies, on top of all the power ram, ssds, and everything else uses. So it will not be an accurate measurement, but it will give you an overall sense of how power hungry it really is. AMD CPU designs have historically been very power hungry, and I expect the new ones to be no different. Looking at how their 7nm GPUs compare against RTX in power consumption leads me to believe the 3000 series will require quite a bit of juice.