5 ms·

I don't know anything about component wear patterns, so a question: would a peak constant temp cause less wear than moderate fluctuations? (And is it fast heati

I don't know anything about component wear patterns, so a question: would a peak constant temp cause less wear than moderate fluctuations? (And is it fast heating/cooling cycles that cause physical stress or is it some other mechanism of action that causes the wear?)

thepasswordis 4y ago
Physical stress of constantly expanding and contracting.
MonkeyClub 4y ago
Haven't been an EE for a couple of lifetimes now, but iirc yes - best to constantly run (within normal operating limits), rather than run and stop and restart. That holds (? used to hold?) true from anything to GPUs to individual capacitors, the repetition of the heat cool cycles is the primary cause of wear.
- parineum 4y ago
  Holds true for a lot of electrical appliances, even lightbulbs. They always blow when you switch the lights on. I'm not sure whether constant running is worse for wear and tear vs power cycling but power cycling is typically what precedes a failure.
  - dhzhzjsbevs 4y ago
    > They always blow when you switch the lights on. This isn't true at all.
    - beebeepka 4y ago
      I've never had one fail in a different manner. Modern LED bulbs seem to fail differently. I see lots of power delivery issues before they go
      - fennecfoxy 4y ago
        Yeah LED bulbs usually have their power supply go long before the LED itself due to inadequate cooling, LEDs themselves last a long, loooong time if properly driven. That failure mode is more, it works fine when initially turned on, then starts failing/flickering on and off once it has gotten to temperature.
  - tempestn 4y ago
    I expect the main reason incandescents tend to fail when the lights are switched on is because the resistance of the filament is lower when cold, so there's a brief spike in current much higher than steady state as it initially heats up.
  - tehbeard 4y ago
    The issue is constant running also has thermal cycles, the variance between peaks is just lower, but can be more rapid. (Spikes from particular instructions being more power hungry). Also in this case we have mechanical components under constant usage (fans), and the effects of long term heat on the thermal compound between the die and cooler plates to consider.
techwiz137 4y ago
The question is by utilizing only a few pathways from core and memory , because the computation never changes aka overusing certain transistors, does the core or memory get damaged? Ethereum mining uses a lot of vram, perhaps the overuses of the memory damages it?
AussieWog93 4y ago
Hot take, but you're not going to get an accurate answer to a question like this online. There are probably about a dozen people on the entire planet who actually understand how and why GPUs fail, and tens of millions who think that the fact they can build a PC qualifies them to present a regurgitated theory from Reddit as "expert opinion".
- sdenton4 4y ago
  ...And mix in a boatload of people getting out of crypto mining with cards to offload, and thus a direct financial interest in blowing hot air.
- margalabargala 4y ago
  > There are probably about a dozen people on the entire planet who actually understand how and why GPUs fail This seems like an underestimation. I would bet there are mid-level hundreds able to articulate at a precise level at least, and dozens of thousands more who are sufficiently familiar with the design and shortcomings modern GPUs and chips who would be able to give an approximately decent answer from first principles. That said, despite my guess being four orders of magnitude larger than yours, the odds of actually encountering such a person among the 7 billion available is practically the same.
  - AussieWog93 4y ago
    I think you'd be surprised. There are surprisingly few people who have a bone-deep understanding of much of the technology that modern civilisation relies on to function.
    - arketyp 4y ago
      I can imagine this being true too. How do you come to these conclusions though?
      - AussieWog93 4y ago
        Pure anecdata. :) I know people who are one-of-a-few experts in technology that is critical to a particular industry, and there's not always good succession plans in place for when they retire. I could absolutely be wrong in this case - it might be well enough understood that you don't need decades of raw experience to begin to scratch the surface - but at the same time there really are so many advanced technologies held together by one or a few experts.
dustractor 4y ago
Heating and cooling, just like what causes cracks in sidewalks. Fast heating and cooling is worse than slow but there is also electromigration which will increasingly become an issue as our process nanometer size decreases. My friend who majored in CS said his teacher recommended always leaving computers on.
throwaway9870 4y ago
Back when I was involved with this, the answer was: "it is hard to answer". A number of years ago, I was working with a Global Foundaries fab on a cutting edge process node and they had no idea how to estimate the lifetime degradation due to high temp. The issue was it was unknown on how to accelerate the effects of high-temp for some of the failure mechanisms. I seem to recall hot-carrier injection being one such mechanism, but I don't recall for sure. If you can't accelerate the failure mechanism in a well defined way, you cannot lab test long-term reliability other than just letting the system run. So if you want to guarantee 10 yrs of lifetime, you need to run it for 10 yrs. Obviously, that doesn't work for most products. Instead you have to rely on models, which, for a new node, might not be proven very well. Bottom line was this vendor shipped products that nobody could really be sure would last the promised lifetime. This was regarded as a top silicon fab in the world. Back then, finer geometries were much harder because of new failure mechanisms. I don't know state of art today, but I would not be surprised if measuring reliability is still not a really hard problem for new nodes. Edit: I am just referring to silicon issues, the rest of the PCB has its own set of issues totally separate. Generally however, those are better understood than a new process node.

thepasswordis 4y ago

Physical stress of constantly expanding and contracting.

MonkeyClub 4y ago

Haven't been an EE for a couple of lifetimes now, but iirc yes - best to constantly run (within normal operating limits), rather than run and stop and restart. That holds (? used to hold?) true from anything to GPUs to individual capacitors, the repetition of the heat cool cycles is the primary cause of wear.

parineum 4y ago
Holds true for a lot of electrical appliances, even lightbulbs. They always blow when you switch the lights on. I'm not sure whether constant running is worse for wear and tear vs power cycling but power cycling is typically what precedes a failure.
- dhzhzjsbevs 4y ago
  > They always blow when you switch the lights on. This isn't true at all.
  - beebeepka 4y ago
    I've never had one fail in a different manner. Modern LED bulbs seem to fail differently. I see lots of power delivery issues before they go
    - fennecfoxy 4y ago
      Yeah LED bulbs usually have their power supply go long before the LED itself due to inadequate cooling, LEDs themselves last a long, loooong time if properly driven. That failure mode is more, it works fine when initially turned on, then starts failing/flickering on and off once it has gotten to temperature.
- tempestn 4y ago
  I expect the main reason incandescents tend to fail when the lights are switched on is because the resistance of the filament is lower when cold, so there's a brief spike in current much higher than steady state as it initially heats up.
- tehbeard 4y ago
  The issue is constant running also has thermal cycles, the variance between peaks is just lower, but can be more rapid. (Spikes from particular instructions being more power hungry). Also in this case we have mechanical components under constant usage (fans), and the effects of long term heat on the thermal compound between the die and cooler plates to consider.

techwiz137 4y ago

The question is by utilizing only a few pathways from core and memory , because the computation never changes aka overusing certain transistors, does the core or memory get damaged? Ethereum mining uses a lot of vram, perhaps the overuses of the memory damages it?

AussieWog93 4y ago

Hot take, but you're not going to get an accurate answer to a question like this online. There are probably about a dozen people on the entire planet who actually understand how and why GPUs fail, and tens of millions who think that the fact they can build a PC qualifies them to present a regurgitated theory from Reddit as "expert opinion".

sdenton4 4y ago
...And mix in a boatload of people getting out of crypto mining with cards to offload, and thus a direct financial interest in blowing hot air.
margalabargala 4y ago
> There are probably about a dozen people on the entire planet who actually understand how and why GPUs fail This seems like an underestimation. I would bet there are mid-level hundreds able to articulate at a precise level at least, and dozens of thousands more who are sufficiently familiar with the design and shortcomings modern GPUs and chips who would be able to give an approximately decent answer from first principles. That said, despite my guess being four orders of magnitude larger than yours, the odds of actually encountering such a person among the 7 billion available is practically the same.
- AussieWog93 4y ago
  I think you'd be surprised. There are surprisingly few people who have a bone-deep understanding of much of the technology that modern civilisation relies on to function.
  - arketyp 4y ago
    I can imagine this being true too. How do you come to these conclusions though?
    - AussieWog93 4y ago
      Pure anecdata. :) I know people who are one-of-a-few experts in technology that is critical to a particular industry, and there's not always good succession plans in place for when they retire. I could absolutely be wrong in this case - it might be well enough understood that you don't need decades of raw experience to begin to scratch the surface - but at the same time there really are so many advanced technologies held together by one or a few experts.

dustractor 4y ago

Heating and cooling, just like what causes cracks in sidewalks. Fast heating and cooling is worse than slow but there is also electromigration which will increasingly become an issue as our process nanometer size decreases. My friend who majored in CS said his teacher recommended always leaving computers on.

throwaway9870 4y ago

Back when I was involved with this, the answer was: "it is hard to answer". A number of years ago, I was working with a Global Foundaries fab on a cutting edge process node and they had no idea how to estimate the lifetime degradation due to high temp. The issue was it was unknown on how to accelerate the effects of high-temp for some of the failure mechanisms. I seem to recall hot-carrier injection being one such mechanism, but I don't recall for sure. If you can't accelerate the failure mechanism in a well defined way, you cannot lab test long-term reliability other than just letting the system run. So if you want to guarantee 10 yrs of lifetime, you need to run it for 10 yrs. Obviously, that doesn't work for most products. Instead you have to rely on models, which, for a new node, might not be proven very well. Bottom line was this vendor shipped products that nobody could really be sure would last the promised lifetime. This was regarded as a top silicon fab in the world. Back then, finer geometries were much harder because of new failure mechanisms. I don't know state of art today, but I would not be surprised if measuring reliability is still not a really hard problem for new nodes. Edit: I am just referring to silicon issues, the rest of the PCB has its own set of issues totally separate. Generally however, those are better understood than a new process node.