5 ms·

I wish they'd included the results of the undervolted 7950x in the graphs (aka ECO mode) It's sad that performance benchmarks have made market conditions where

I wish they'd included the results of the undervolted 7950x in the graphs (aka ECO mode) It's sad that performance benchmarks have made market conditions where the gain of 5% performance is somehow worth 20%-30% extra power consumption (and the noise that follows from that)

alyandon 4y ago
I just disable PBO on my 3900X - you are 100% correct that an extra 5% performance is not worth the extra 30% power draw/heat.
- CharlesW 4y ago
  For anyone else not familiar with "PBO", it's AMD's "Precision Boost Overdrive", which is apparently completely different than Precision Boost and Precision Boost 2: https://www.gamersnexus.net/guides/3491-explaining-precision-boost-overdrive-benchmarks-auto-oc https://www.gamersnexus.net/guides/3491-explaining-precision...
- caycep 4y ago
  This is the same as AMD "Eco Mode"?
  - 0cf8612b2e1e 4y ago
    I just turned on Eco Mode last night and was pleasantly surprised. In a non rigorous test on my 5600x, Eco Mode had zero change to single core performance, unchanged CPU temp. Multicore saw a 3% performance drop, but temps were ~12C cooler. Test yourself, but I am definitely going to leave it enabled.
    - merb 4y ago
      a 5600x runs at only 65w or so and can be cooled down to 40C like all the time. I'm not sure if I would prefer to run it at 16w lower, because I bareley even reach the tdp or even tjmax.
- anticensor 4y ago
  PBO also allows undervolting though: I just applied -30 all core offset on my 5950X.
  - asynchronyse 4y ago
    I'm wondering how much clock speed you gave up to achieve stability at -30. I could barely be stable at -15 all core on a 5900X at zero clock offset.
    - anticensor 4y ago
      About 300Mhz on each core on average, but the peak frequency on the best core did not change.
mastax 4y ago
The X3D chips do at least have a reduced TDP of 120W vs 170W (except for the 7800X3D vs the confusingly comparable 7700X's 105W). The other thing is that, at least in DIY PC (and botique builders like CyberPower) the "gaming" motherboards universally increase the maximum peak power target and also commonly enable things like all core turbo and precision boost overdrive by default. So unless they specify otherwise, like AnandTech I think, you can assume most reviewers will be running the CPU with more power than the spec but that's a common situation for their audience.
- paulmd 4y ago
  > The other thing is that, at least in DIY PC (and botique builders like CyberPower) the "gaming" motherboards universally increase the maximum peak power target Worth noting the PPT is higher than the TDP by default - a "120W" AMD chip is actually allowed to boost to 168W continuously, obviously they prefer to advertise the former and have people making comparisons between "120W" AMD and Intel chips running at full boost PPT. X3D chips are a cut above the rest of the market in terms of efficiency (although this mostly springs from the clock restrictions imposed by the v-cache CCD, which is undesirable and will be removed/mitigated once the technology permits) but in the rest of the lineup this slides them much closer to the Intel line than AMD would prefer people to think about. A 170W TDP 7950X is actually 220W, a 125W 7800X is actually 170W. People reflexively think in terms of AMD's marketing TDPs when making comparisons and don't account for the fact that the chips are allowed by the spec to boost way above that. And it's been incredibly successful - every single AMD thread there's someone talking about their nice efficient 65W processor and lol unless you turned off the boost (which is separate from just enabling eco!) then no, it's not 65W. Still good, still usually more efficient than Intel, but AMD gave themselves an instant 30% edge on paper with the power of clever marketing and that's always been a significant amount, enough to swing purchases. That part is not something that gaming motherboards do automatically, and I've never seen one that will enable multicore enhancement-style tuning by default. If you enable overclocking yourself (and enabling XMP/DOCP is considered overclocking since this usually increases VSOC or VCCSA to allow the memory controller to run faster than spec) then all bets are off but by default no, they shouldn't be, just the terminology difference that springs from AMD's marketing trickery around TDP vs PPT. And hey if people end up blaming partners for AMD's spec... that's just good marketing work. PBO is the setting where you'd see power limits increased and I've never seen that on by default, it's always hidden behind a "THIS VOIDS YOUR WARRANTY AND KILLS YOUR DOG" disclaimer in a separate panel.

alyandon 4y ago

I just disable PBO on my 3900X - you are 100% correct that an extra 5% performance is not worth the extra 30% power draw/heat.

CharlesW 4y ago
For anyone else not familiar with "PBO", it's AMD's "Precision Boost Overdrive", which is apparently completely different than Precision Boost and Precision Boost 2: https://www.gamersnexus.net/guides/3491-explaining-precision-boost-overdrive-benchmarks-auto-oc https://www.gamersnexus.net/guides/3491-explaining-precision...
caycep 4y ago
This is the same as AMD "Eco Mode"?
- 0cf8612b2e1e 4y ago
  I just turned on Eco Mode last night and was pleasantly surprised. In a non rigorous test on my 5600x, Eco Mode had zero change to single core performance, unchanged CPU temp. Multicore saw a 3% performance drop, but temps were ~12C cooler. Test yourself, but I am definitely going to leave it enabled.
  - merb 4y ago
    a 5600x runs at only 65w or so and can be cooled down to 40C like all the time. I'm not sure if I would prefer to run it at 16w lower, because I bareley even reach the tdp or even tjmax.
anticensor 4y ago
PBO also allows undervolting though: I just applied -30 all core offset on my 5950X.
- asynchronyse 4y ago
  I'm wondering how much clock speed you gave up to achieve stability at -30. I could barely be stable at -15 all core on a 5900X at zero clock offset.
  - anticensor 4y ago
    About 300Mhz on each core on average, but the peak frequency on the best core did not change.

mastax 4y ago

The X3D chips do at least have a reduced TDP of 120W vs 170W (except for the 7800X3D vs the confusingly comparable 7700X's 105W). The other thing is that, at least in DIY PC (and botique builders like CyberPower) the "gaming" motherboards universally increase the maximum peak power target and also commonly enable things like all core turbo and precision boost overdrive by default. So unless they specify otherwise, like AnandTech I think, you can assume most reviewers will be running the CPU with more power than the spec but that's a common situation for their audience.

paulmd 4y ago
> The other thing is that, at least in DIY PC (and botique builders like CyberPower) the "gaming" motherboards universally increase the maximum peak power target Worth noting the PPT is higher than the TDP by default - a "120W" AMD chip is actually allowed to boost to 168W continuously, obviously they prefer to advertise the former and have people making comparisons between "120W" AMD and Intel chips running at full boost PPT. X3D chips are a cut above the rest of the market in terms of efficiency (although this mostly springs from the clock restrictions imposed by the v-cache CCD, which is undesirable and will be removed/mitigated once the technology permits) but in the rest of the lineup this slides them much closer to the Intel line than AMD would prefer people to think about. A 170W TDP 7950X is actually 220W, a 125W 7800X is actually 170W. People reflexively think in terms of AMD's marketing TDPs when making comparisons and don't account for the fact that the chips are allowed by the spec to boost way above that. And it's been incredibly successful - every single AMD thread there's someone talking about their nice efficient 65W processor and lol unless you turned off the boost (which is separate from just enabling eco!) then no, it's not 65W. Still good, still usually more efficient than Intel, but AMD gave themselves an instant 30% edge on paper with the power of clever marketing and that's always been a significant amount, enough to swing purchases. That part is not something that gaming motherboards do automatically, and I've never seen one that will enable multicore enhancement-style tuning by default. If you enable overclocking yourself (and enabling XMP/DOCP is considered overclocking since this usually increases VSOC or VCCSA to allow the memory controller to run faster than spec) then all bets are off but by default no, they shouldn't be, just the terminology difference that springs from AMD's marketing trickery around TDP vs PPT. And hey if people end up blaming partners for AMD's spec... that's just good marketing work. PBO is the setting where you'd see power limits increased and I've never seen that on by default, it's always hidden behind a "THIS VOIDS YOUR WARRANTY AND KILLS YOUR DOG" disclaimer in a separate panel.