7 ms·

In a similar vein, from memory the i3, i5 & i7 chip is absolutely identical in every physical way from a manufacturing point of view, except that the less power

by a10c 5y ago

In a similar vein, from memory the i3, i5 & i7 chip is absolutely identical in every physical way from a manufacturing point of view, except that the less powerful chips have cores / features disabled.

pc86 5y ago
I have to wonder why this is done. I know it must make sense or it wouldn't be done, I just don't understand it. If you're intentionally disabling functionality in order to sell at a lower cost, you're not actually saving any money because you still have to manufacture the thing. It also (I assume) opens up a risk to someone finding out how to "jailbreak" the extra cores and now you can buy an i7 for the price of an i3. Is the cost of having three different manufacturing processes so large that it's not worth switching? Is the extra revenue from having three different versions of the same physical chip enough to justify the jailbreak risk?
- lordnacho 5y ago
  I think of you Google price discrimination or similar economic terms you get some explanations for this. If you just have one price, you cut out people who can't afford it and people who can afford to pay more get away with more of the surplus. If you have several prices and create just enough difference in the product that it doesn't change the expense much, you can suck dry every class of user. Bit of an MBA trick.
  - lupire 5y ago
    "suck dry" is excessive editorializing for a practice that make sit possible for a market to exist without, well, "sucking the manufacturer dry".
    - Rastonbury 5y ago
      Exactly, it is not an economics trick for if companies could only supply a certain level of the market it might not even be profitable to produce. It is just economics... We are talking about chips here so not the same bottle of soap with different labels, I'd call that a trick.
- boygobbo 5y ago
  It's called 'market segmentation'. It's why there are different brands of soap powder from the same manufacturer even though they are all essentially the same.
  - HeavyStorm 5y ago
    Yep. I don't think it has anything to do with manufacture issues.
    - HumblyTossed 5y ago
      > I don't think... Instead of assuming, it's easy enough to confirm that CPU binning is real.
- MontyCarloHall 5y ago
  This is done with cores/memory banks that didn’t pass QC. For example, a 6 core CPU and an 8 core CPU might have the same die as a 12 core CPU, but 6/4 cores, respectively, were defective, so they get disabled. I don’t think they’re crippling fully functional hardware. See here: http://isca09.cs.columbia.edu/pres/09.pdf http://isca09.cs.columbia.edu/pres/09.pdf Also here: https://www.anandtech.com/show/2721 https://www.anandtech.com/show/2721 “When AMD produces a Phenom II die if part of the L3 is bad, it gets disabled and is sold as an 800 series chip. If one of the cores is bad, it gets disabled and is sold as a 700 series chip. If everything is in working order, then we've got a 900.”
  - flyinghamster 5y ago
    Specifically regarding Phenom II, I have a 550 Black Edition still plugging away, serving different roles over the years, and I was able to successfully unlock and run the two locked-out cores (via a BIOS option). It's never skipped a beat at stock clock. It could be that there was an oversupply of quad-cores, or perhaps (since it was a Black Edition part marketed to overclockers) the extra cores failed when overclocked. I know I wasn't able to have both overclock and four cores, but I considered the extra cores more important, since it was already a reasonably fast chip for its day.
    - SAI_Peregrinus 5y ago
      It's likely the latter (that it couldn't work when overclocked with all cores). The market for those is to allow overclocking, so if it can't do any overclocking with all cores AMD likely wouldn't want to sell it as a 4-core Black Edition, since it'd probably just get returned.
  - gurkendoktor 5y ago
    > ...but 6/4 cores, respectively, were defective, so they get disabled. I don’t think they’re crippling fully functional hardware. Hmm, but what if 3 cores are defective? If that can happen(?), then it seems one extra functional core is disabled to get to an even core number. Apple's M1 GPUs are the first where I've seen the choice between 7 and 8 cores (as opposed to 6/8 or 4/8).
- Peaches4Rent 5y ago
  That's because there is a huge variance in the quality of chips produced because the process isn't 100% precise. So the best chips which have the least errors in the manufacturing process are sold as top tier. The ones which have more mistakes in them get their defective parts disabled and then get sold as lower tier ones
- rickdeckard 5y ago
  This is done because your production yield is not 100%. So instead of throwing away every produced component which doesn't achieve the target of your 100%-product, you "soft-lock" the components with 80~99% performance into a 80%-product category, and the ones with 60~80% into a 60%-product. This way you increase the total yield-rate, and produce less waste. The counter-intuitive waste happens when the demand for the 60%-product is exceeding your "natural" supply of 60%-output, so you have to start to "soft-lock" some of your "80%-product" production to the 60%-grade to fulfill demand...
  - zingar 5y ago
    But do these production defects really meet the demand of the lower tiers? Also how is it possible to predict the number of defects in advance so that they can make useful promises to distributors?
    - mekkkkkk 5y ago
      I'm curious about this as well. It seems inevitable that some batches will be "too good" to satisfy demand of low end chips. Either they just accept the fluctuations in order to maximize output of high end chips, or they would have to cripple fully functional ones to maintain a predictable supply. Interesting business.
      - BeeOnRope 5y ago
        It's not primarily about using defective chips (but that's a nice side effect). As a process becomes mature, yield rates become very high and there wouldn't be enough defective chips to meet demand for a lower tier, so good chips are binned into those tiers anyway. The primary purpose is market segmentation: extracting value from customers who would pay more while not giving up sales to more price sensitive clients who nevertheless pay more than the marginal cost of production.
        mekkkkkk 5y ago
        That makes sense, thanks. I wonder if it would be possible to de-bin one of the lower end ones, assuming it is a binned version of a fully functional higher tier chip. Or perhaps they completely destroy the offlined cores/features.
- jffry 5y ago
  The term for this is "binning", and the explanation is wholly innocent. Manufacturing silicon chips is not an exact process, and there will be some rate of defects. After manufacture, they test the individual components of their chips. These chips are designed in such a way that once they identify parts of a chip that are defective, they can disconnect that part of the chip and the others still work. (I believe they physically cut stuff with lasers but my knowledge is out of date). This process can also includes "burning in" information on the chip itself, like setting bits in on-die ROMs, so that if your OS asks your CPU for its model number it can respond appropriately. Interesting side note: The same thing happens when manufacturing even basic electronic components like resistors. All the resistors that are within 1% of the target resistance get sold as "±1%" resistors, which means it's pretty likely that if you buy the cheaper "±5%" resistors and test them, you'll find two clusters around -5% and +5% and very few at the target value.
  - magicalhippo 5y ago
    > The same thing happens when manufacturing even basic electronic components like resistors. EEVblog did some tests[1][2] some time ago on ±1% resistors, and found that while his samples were fairly Gaussian and within the spec, the ones from his second batch were consistently low. That is, none were above the rated value. So yeah, don't assume a perfect Gaussian distribution when using resistors. [1]: https://www.youtube.com/watch?v=1WAhTdWErrU https://www.youtube.com/watch?v=1WAhTdWErrU [2]: https://www.youtube.com/watch?v=kSmiDzbVt_U https://www.youtube.com/watch?v=kSmiDzbVt_U
sly010 5y ago
No manufacturing process is perfect, so you just sort, label and price the output accordingly. This is fairly normal practice. LEDs, vegetables, even eggs...

by a10c 5y ago

pc86 5y ago

I have to wonder why this is done. I know it must make sense or it wouldn't be done, I just don't understand it. If you're intentionally disabling functionality in order to sell at a lower cost, you're not actually saving any money because you still have to manufacture the thing. It also (I assume) opens up a risk to someone finding out how to "jailbreak" the extra cores and now you can buy an i7 for the price of an i3. Is the cost of having three different manufacturing processes so large that it's not worth switching? Is the extra revenue from having three different versions of the same physical chip enough to justify the jailbreak risk?

lordnacho 5y ago
I think of you Google price discrimination or similar economic terms you get some explanations for this. If you just have one price, you cut out people who can't afford it and people who can afford to pay more get away with more of the surplus. If you have several prices and create just enough difference in the product that it doesn't change the expense much, you can suck dry every class of user. Bit of an MBA trick.
- lupire 5y ago
  "suck dry" is excessive editorializing for a practice that make sit possible for a market to exist without, well, "sucking the manufacturer dry".
  - Rastonbury 5y ago
    Exactly, it is not an economics trick for if companies could only supply a certain level of the market it might not even be profitable to produce. It is just economics... We are talking about chips here so not the same bottle of soap with different labels, I'd call that a trick.
boygobbo 5y ago
It's called 'market segmentation'. It's why there are different brands of soap powder from the same manufacturer even though they are all essentially the same.
- HeavyStorm 5y ago
  Yep. I don't think it has anything to do with manufacture issues.
  - HumblyTossed 5y ago
    > I don't think... Instead of assuming, it's easy enough to confirm that CPU binning is real.
MontyCarloHall 5y ago
This is done with cores/memory banks that didn’t pass QC. For example, a 6 core CPU and an 8 core CPU might have the same die as a 12 core CPU, but 6/4 cores, respectively, were defective, so they get disabled. I don’t think they’re crippling fully functional hardware. See here: http://isca09.cs.columbia.edu/pres/09.pdf http://isca09.cs.columbia.edu/pres/09.pdf Also here: https://www.anandtech.com/show/2721 https://www.anandtech.com/show/2721 “When AMD produces a Phenom II die if part of the L3 is bad, it gets disabled and is sold as an 800 series chip. If one of the cores is bad, it gets disabled and is sold as a 700 series chip. If everything is in working order, then we've got a 900.”
- flyinghamster 5y ago
  Specifically regarding Phenom II, I have a 550 Black Edition still plugging away, serving different roles over the years, and I was able to successfully unlock and run the two locked-out cores (via a BIOS option). It's never skipped a beat at stock clock. It could be that there was an oversupply of quad-cores, or perhaps (since it was a Black Edition part marketed to overclockers) the extra cores failed when overclocked. I know I wasn't able to have both overclock and four cores, but I considered the extra cores more important, since it was already a reasonably fast chip for its day.
  - SAI_Peregrinus 5y ago
    It's likely the latter (that it couldn't work when overclocked with all cores). The market for those is to allow overclocking, so if it can't do any overclocking with all cores AMD likely wouldn't want to sell it as a 4-core Black Edition, since it'd probably just get returned.
- gurkendoktor 5y ago
  > ...but 6/4 cores, respectively, were defective, so they get disabled. I don’t think they’re crippling fully functional hardware. Hmm, but what if 3 cores are defective? If that can happen(?), then it seems one extra functional core is disabled to get to an even core number. Apple's M1 GPUs are the first where I've seen the choice between 7 and 8 cores (as opposed to 6/8 or 4/8).
Peaches4Rent 5y ago
That's because there is a huge variance in the quality of chips produced because the process isn't 100% precise. So the best chips which have the least errors in the manufacturing process are sold as top tier. The ones which have more mistakes in them get their defective parts disabled and then get sold as lower tier ones
rickdeckard 5y ago
This is done because your production yield is not 100%. So instead of throwing away every produced component which doesn't achieve the target of your 100%-product, you "soft-lock" the components with 80~99% performance into a 80%-product category, and the ones with 60~80% into a 60%-product. This way you increase the total yield-rate, and produce less waste. The counter-intuitive waste happens when the demand for the 60%-product is exceeding your "natural" supply of 60%-output, so you have to start to "soft-lock" some of your "80%-product" production to the 60%-grade to fulfill demand...
- zingar 5y ago
  But do these production defects really meet the demand of the lower tiers? Also how is it possible to predict the number of defects in advance so that they can make useful promises to distributors?
  - mekkkkkk 5y ago
    I'm curious about this as well. It seems inevitable that some batches will be "too good" to satisfy demand of low end chips. Either they just accept the fluctuations in order to maximize output of high end chips, or they would have to cripple fully functional ones to maintain a predictable supply. Interesting business.
    - BeeOnRope 5y ago
      It's not primarily about using defective chips (but that's a nice side effect). As a process becomes mature, yield rates become very high and there wouldn't be enough defective chips to meet demand for a lower tier, so good chips are binned into those tiers anyway. The primary purpose is market segmentation: extracting value from customers who would pay more while not giving up sales to more price sensitive clients who nevertheless pay more than the marginal cost of production.
      - mekkkkkk 5y ago
        That makes sense, thanks. I wonder if it would be possible to de-bin one of the lower end ones, assuming it is a binned version of a fully functional higher tier chip. Or perhaps they completely destroy the offlined cores/features.
jffry 5y ago
The term for this is "binning", and the explanation is wholly innocent. Manufacturing silicon chips is not an exact process, and there will be some rate of defects. After manufacture, they test the individual components of their chips. These chips are designed in such a way that once they identify parts of a chip that are defective, they can disconnect that part of the chip and the others still work. (I believe they physically cut stuff with lasers but my knowledge is out of date). This process can also includes "burning in" information on the chip itself, like setting bits in on-die ROMs, so that if your OS asks your CPU for its model number it can respond appropriately. Interesting side note: The same thing happens when manufacturing even basic electronic components like resistors. All the resistors that are within 1% of the target resistance get sold as "±1%" resistors, which means it's pretty likely that if you buy the cheaper "±5%" resistors and test them, you'll find two clusters around -5% and +5% and very few at the target value.
- magicalhippo 5y ago
  > The same thing happens when manufacturing even basic electronic components like resistors. EEVblog did some tests[1][2] some time ago on ±1% resistors, and found that while his samples were fairly Gaussian and within the spec, the ones from his second batch were consistently low. That is, none were above the rated value. So yeah, don't assume a perfect Gaussian distribution when using resistors. [1]: https://www.youtube.com/watch?v=1WAhTdWErrU https://www.youtube.com/watch?v=1WAhTdWErrU [2]: https://www.youtube.com/watch?v=kSmiDzbVt_U https://www.youtube.com/watch?v=kSmiDzbVt_U

sly010 5y ago

No manufacturing process is perfect, so you just sort, label and price the output accordingly. This is fairly normal practice. LEDs, vegetables, even eggs...