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I really wish that someone would review CPUs at similar power levels, rather than TDP when there is a big difference between the two models. Also, there is no
by AshamedCaptain 4y ago
I really wish that someone would review CPUs at similar power levels, rather than TDP when there is a big difference between the two models.
Also, there is no idle power comparison, something that may also differ significantly and affect Linux.
- devwastaken 4y agoWhat would be the purpose? If you want to purposefully limit power you're forcing the chip to underperform. You can just get the lower cost chip that does run at that power. For example the 5600x being 76W versus the higher chips.
- fomine3 4y agoIt's not the same. Many core on lower frequency is efficient than fewer core on high frequency, even if TDP is same.
- pizza234 4y ago> What would be the purpose? If you want to purposefully limit power you're forcing the chip to underperform The rationale is that each architecture has a sweet spot consumption/performance, and increasing performance over a certain threshold has increasing costs (AFAIK, one significant factor is the increase of voltage in order to push frequencies higher). I don't know the numbers, but AMD has been offering the 65W threshold for a while, so it can be reasonably assumed that 65W is the sweet spot performance/consumption. The reason for not buying directly a cheaper model is the number of cores - one may choose, say, a 65W-throttled CPU with 16 cores over an unthrottled 8-cores (in some scenarios, this can make sense).
- Kerrick 4y agoIn addition to this, you can choose to run your top-of-the-line multi-core processor in eco mode most of the time, and then consciously turn it back to stock settings when you know you'll need the extra speed/throughput, only bearing the extra heat and cost of that performance when you really need it.
- BaculumMeumEst 4y agoi like longer lasting hardware and not having a furnace in my office
- AshamedCaptain 4y agoAs shown in the anandtech review above, the 7950x limited to 65W (ECO Mode) handily beats the 7600x at (uncapped) 105W, and anecdotally everything that Intel has to offer as of today... https://www.anandtech.com/show/17585/amd-zen-4-ryzen-9-7950x-and-ryzen-5-7600x-review-retaking-the-high-end/20 https://www.anandtech.com/show/17585/amd-zen-4-ryzen-9-7950x...
- nine_k 4y ago(1) Battery life on laptops. (2) Cooling budget on servers. Both are very significant limiting factors for non-gaming applications. Top gaming rigs are the dragsters of computing: no power consumption is too high, no hardware contraption is too large. But most people, and most businesses, don't drive dragsters.
- arianvanp 4y agoBut a 7950x is just a 7900x (They have identical silicon) that is just "lucky" enough to survive more power draw. If you make the TDP the same you just end up with the same CPU
- Ygg2 4y agoPretty sure 7900x has fewer cores/threads.
- pizza234 4y agoAre you sure? The 7900x has 12 cores, while the 7950x has 16.
- Bolkan 4y agoThey disable some cores? How else would you explain the lower single core performance?
- Scene_Cast2 4y agoI did read that the silicon that can take higher voltages is worse in lower power (i.e. lower voltage) situations.
- fomine3 4y agoThis is my request for CPU review. It's good way to know core efficiency. TDP or turbo watts is now artificially set very high by manufacturer but not efficient. Maybe reviewers are too busy to take many benchmarks before embargo.
- doikor 4y agoGamers nexus kind of does that https://www.youtube.com/watch?v=nRaJXZMOMPU&t=704s https://www.youtube.com/watch?v=nRaJXZMOMPU&t=704s Basically how many watts required to do some fix unit of work (to render 1 frame using Blender CPU rendering)
- Bolkan 4y agoYour cpu can simulate the universe at 1W. Although it will take a long time.
- ncmncm 4y agoMy CPU can't, but it is theoretically possible to make a CPU that could.
- plasticchris 4y agodo you mean that a turing machine can't simulate the universe but some other kind of cpu (i.e. quantum) could?
- jhoechtl 4y agoThis is all very theoretical so ... a turing machine can simulate a universe as it assumes infinite memory
- ncmncm 4y agoNo, I mean that it is physically possible to perform an unlimited amount of computation on a fixed amount of energy, if you are willing to wait long enough. Nobody has built hardware that has this property.
- NathanielK 4y ago1W is one joule per second. With unlimited time, you also have unlimited joules trickling out.
- rndmize 4y agoThe anandtech review has some of that, they have one chart on the 7950X running in eco mode https://www.anandtech.com/show/17585/amd-zen-4-ryzen-9-7950x-and-ryzen-5-7600x-review-retaking-the-high-end/20 https://www.anandtech.com/show/17585/amd-zen-4-ryzen-9-7950x... .
- neogodless 4y agoYes scroll down to see the Cinebench R23 results at 65W.
- nwmcsween 4y agoI just want a CPU freq to power chart, so I know how Intel/AMD are pushing TDP and at what freq things start getting exponential. It would be interesting to see what is considered "normal".
- Scene_Cast2 4y agoThere was a test done on 12th gen Intel (12900 variant IIRC, but my memory is hazy). They limited TDP incrementally down to single-digit numbers, the efficiency kept increasing the farther down you go. My takeaway was that there isn't a "normal" or "optimum".
- nwmcsween 4y agoFreq/Power will be linear to a point, it's possible the point differs on different processors but maybe not.
- NathanielK 4y agoPresumably that's when you hit the minimum voltage the CPU is allowed to run at. There's still a few other gotchas though. As CPU frequency goes down, it waits less cycles for RAM. Practically it's a bit of a copout since keeping your RAM at high clocks/voltages doesn't effect more CPU TDP but does use more power. It might explain some of the irregularities in testing at least.