5 ms·

> And if one atom is in the wrong place, you have to throw away the chip this is certainly the case for CPU but DRAM & NAND ? this is the typical case of desi

by maxhou 11y ago

> And if one atom is in the wrong place, you have to throw away the chip this is certainly the case for CPU but DRAM & NAND ? this is the typical case of designs where you can add redundancy to accomodate for manufacturing defects.

mozumder 11y ago
At the cost of increased die-size. If it helps any just think of the costs as buying diamonds. "Wow that's 16TB of diamonds!" or: "this GPU uses a bigger diamond than that GPU"
- hbosch 11y ago
  It doesn't exactly help your cause that many people also believe the cost of diamonds is artificially inflated as well.
  - kedean 11y ago
    The cost of diamonds IS artificially inflated. They are useful for purposes other than the one in which the price inflation is a big deal, but it is a demonstrable fact that the price is inflated.
    - simoncion 11y ago
      The cost of industrial diamonds is -one presumes- not subject to much artificial inflation.
- XorNot 11y ago
  Only problem with that is that a silicon wafer is like $50 off the shelf individually. They are incredibly cheap.
  - mozumder 11y ago
    That's still a lot more expensive than aluminum platters. And you will need a lot of silicon to produce an SSD. You don't do it with just one chip.
    - XorNot 11y ago
      That price is for single wafers off the shelf. They get a lot cheaper if you buy bulk, and you can slice them a lot thinner then the sizes I used to use (where I know the price from).
- simoncion 11y ago
  > If it helps any just think of the costs as buying diamonds. This is an unhelpful analogy. Comparing the retail price of diamonds to the retail price of CPUs, RAM boards, and GPUs, I am lead to believe that whatever is used as the substrate for modern high-performance ICs is actually rather cheap. I can -after all- get a reasonably fast combination CPU and GPU for $45. If we ask the USGS, we discover that in 2003, the price of synthetic diamond suitable for reinforcing saws and drills sold for $1.50->$3.50 per carat. However, large synthetic diamonds with "excellent structure" suitable for -one presumes- processes that rely on the crystal's fine structural properties -just as CPU manufacture relies on silicon wafers with fine structural properties-, sold for "many hundreds of dollars per carat". [0] One carat is 200 milligrams. An entire Core i3 appears to weigh 26,800mg [1]. Let's be generous and assume that the CPU die is 1/1000th of that weight, or 268mg, or 1.32 carats. Given that CPU manufacture requires a substrate with excellent structure, just how much of a substance that costs many hundreds of dollars per carat can there be in a 1.32 carat device? (Especially when ones of similar weight constructed with similar materials can be had for $45 per, retail?) :) [0] http://minerals.usgs.gov/minerals/pubs/commodity/diamond/diamomyb03.pdf http://minerals.usgs.gov/minerals/pubs/commodity/diamond/dia... [1] http://www.cpu-world.com/CPUs/Core_i3/Intel-Core%20i3-2100%20CM8062301061600.html http://www.cpu-world.com/CPUs/Core_i3/Intel-Core%20i3-2100%2...
  - Dylan16807 11y ago
    Yes, a wafer is something like a hundred dollars, that's not the expensive part.
    - simoncion 11y ago
      I know that the substrate isn't the expensive part. Even a cursory gut-check reveals a claim to the contrary to be bunk. I felt that a somewhat detailed analysis of the inappropriateness of the analogy was better than a "Nuh uh! You're wrong!" response.
      - Dylan16807 11y ago
        Well the thing is you're analyzing in a way that's both in-depth and shallow at the same time. It doesn't matter that they have 'excellent structure' unless you care about actual wafer costs. Just use diamond prices and dimensions.
farresito 11y ago
I thought the reason that there are so many different models (i3, i5, and i7, for example) is that the more defects it has, the more the surface that becomes unusable, thus reducing the amount of transistors in use (which is why i3 are less powerful than i5). Don't they technically have some sort of redundancy?
- maxhou 11y ago
  The most obvious is that they have multiple cores, and it's easy to completely disable a non functional one. Now can Intel be more granular than the core level, like running a core with some defect ALU, I really don't know. What's publicly known from the binning process is that it involves disabling core, reducing total cache size, and finding the maximum working frequency. The bottom line is that it requires more effort to deal with defects in complex logic, for DRAM they would reduce the total memory size.

by maxhou 11y ago

mozumder 11y ago

At the cost of increased die-size. If it helps any just think of the costs as buying diamonds. "Wow that's 16TB of diamonds!" or: "this GPU uses a bigger diamond than that GPU"

hbosch 11y ago
It doesn't exactly help your cause that many people also believe the cost of diamonds is artificially inflated as well.
- kedean 11y ago
  The cost of diamonds IS artificially inflated. They are useful for purposes other than the one in which the price inflation is a big deal, but it is a demonstrable fact that the price is inflated.
  - simoncion 11y ago
    The cost of industrial diamonds is -one presumes- not subject to much artificial inflation.
XorNot 11y ago
Only problem with that is that a silicon wafer is like $50 off the shelf individually. They are incredibly cheap.
- mozumder 11y ago
  That's still a lot more expensive than aluminum platters. And you will need a lot of silicon to produce an SSD. You don't do it with just one chip.
  - XorNot 11y ago
    That price is for single wafers off the shelf. They get a lot cheaper if you buy bulk, and you can slice them a lot thinner then the sizes I used to use (where I know the price from).
simoncion 11y ago
> If it helps any just think of the costs as buying diamonds. This is an unhelpful analogy. Comparing the retail price of diamonds to the retail price of CPUs, RAM boards, and GPUs, I am lead to believe that whatever is used as the substrate for modern high-performance ICs is actually rather cheap. I can -after all- get a reasonably fast combination CPU and GPU for $45. If we ask the USGS, we discover that in 2003, the price of synthetic diamond suitable for reinforcing saws and drills sold for $1.50->$3.50 per carat. However, large synthetic diamonds with "excellent structure" suitable for -one presumes- processes that rely on the crystal's fine structural properties -just as CPU manufacture relies on silicon wafers with fine structural properties-, sold for "many hundreds of dollars per carat". [0] One carat is 200 milligrams. An entire Core i3 appears to weigh 26,800mg [1]. Let's be generous and assume that the CPU die is 1/1000th of that weight, or 268mg, or 1.32 carats. Given that CPU manufacture requires a substrate with excellent structure, just how much of a substance that costs many hundreds of dollars per carat can there be in a 1.32 carat device? (Especially when ones of similar weight constructed with similar materials can be had for $45 per, retail?) :) [0] http://minerals.usgs.gov/minerals/pubs/commodity/diamond/diamomyb03.pdf http://minerals.usgs.gov/minerals/pubs/commodity/diamond/dia... [1] http://www.cpu-world.com/CPUs/Core_i3/Intel-Core%20i3-2100%20CM8062301061600.html http://www.cpu-world.com/CPUs/Core_i3/Intel-Core%20i3-2100%2...
- Dylan16807 11y ago
  Yes, a wafer is something like a hundred dollars, that's not the expensive part.
  - simoncion 11y ago
    I know that the substrate isn't the expensive part. Even a cursory gut-check reveals a claim to the contrary to be bunk. I felt that a somewhat detailed analysis of the inappropriateness of the analogy was better than a "Nuh uh! You're wrong!" response.
    - Dylan16807 11y ago
      Well the thing is you're analyzing in a way that's both in-depth and shallow at the same time. It doesn't matter that they have 'excellent structure' unless you care about actual wafer costs. Just use diamond prices and dimensions.

farresito 11y ago

I thought the reason that there are so many different models (i3, i5, and i7, for example) is that the more defects it has, the more the surface that becomes unusable, thus reducing the amount of transistors in use (which is why i3 are less powerful than i5). Don't they technically have some sort of redundancy?

maxhou 11y ago
The most obvious is that they have multiple cores, and it's easy to completely disable a non functional one. Now can Intel be more granular than the core level, like running a core with some defect ALU, I really don't know. What's publicly known from the binning process is that it involves disabling core, reducing total cache size, and finding the maximum working frequency. The bottom line is that it requires more effort to deal with defects in complex logic, for DRAM they would reduce the total memory size.