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So when buying an i5 I am in fact getting much more performance per cost compared to the i7, because Intel decided to make the i7 much more expensive in order t

by Sammi 10y ago

So when buying an i5 I am in fact getting much more performance per cost compared to the i7, because Intel decided to make the i7 much more expensive in order to make the i5 seem like it has much better performance per cost?

mrmondo 10y ago
Is the cache size and turbo boost the same though?
legodt 10y ago
It's also much more expensive to produce an i7. i7 are near perfect chips and are able to run higher clock rate efficiently and safely while i5s are more "standard" and have their performance clamped down to what they can safely handle. There are less i7 chips rolling off the lines, which increases their price. Hopefully somebody who knows more about this than me can jump in and fill in the blanks here. EDIT: I communicated my point poorly and the comments below mine explain this is much clearer terms
- dragontamer 10y ago
  I don't know Intel's specifics, but often there's only a few chips that a manufacturer makes... and depending on the Quality / testing of the chips... the chips are binned into different categories. As a hypothetical example (I'm not 100% sure if this is how Intel does things), and i5 could just be an i7 except it couldn't handle the higher clock rate. So instead of throwing away a chip that's limited in clock... Intel will sell the chip as an i5. Or perhaps in another chip, the hyperthreading portion got borked because of a piece of dust landed in the lithography. So instead of selling it as an i7, the hyperthreading portion is fused off and the chip is sold as an i5.
  - legodt 10y ago
    You're the guy who knew more and filled in the blanks! I am super fascinated by this topic (and an outsider). Do you have any specific examples or situations that you know of this happening? The hypothetical you gave above was awesome and now I'm curious for more.
    - dragontamer 10y ago
      AMD's Tricore vs Quadcore... something (I think Phentoms??) were definitely this. Some Tricores were able to turn into quad-cores with some firmware hacking. The IBM-Cell in the PS3 was a different approach to the same problem. The Cell was specified as 7-SPUs and 1-CPU, but in actuality... the manufacturing process made 8-SPUs and 1-CPU. IBM assumed that one of the SPUs would fail during manufacturing, so they only promised to deliver 7 of them per PS3. You can literally see the 8 SPUs: https://upload.wikimedia.org/wikipedia/commons/e/e0/Cell-Processor.jpg https://upload.wikimedia.org/wikipedia/commons/e/e0/Cell-Pro... There's lots of ways to approach the problem. Manufacturing is an imperfect process: not everything is made identically. So the manufacturers have to figure out how to test for differences and... if necessary... sell the same "manufactured" chip in different bins.
      - legodt 10y ago
        Thanks for taking the time to go further on this and link that image, very cool stuff.
      - Fnoord 10y ago
        > AMD's Tricore vs Quadcore... something (I think Phentoms??) Phenom. https://en.wikipedia.org/wiki/AMD_Phenom https://en.wikipedia.org/wiki/AMD_Phenom https://en.wikipedia.org/wiki/Phenom_II https://en.wikipedia.org/wiki/Phenom_II Not all the hardware of Cell on PS3 was available if you run the official Linux port. Which was later blatantly removed.
- mohaine 10y ago
  Historically, I don't think it has worked like this for Intel. It costs way more to have multiple designs so they are all pretty much the same few chips with the packaging changed to disable parts. Sometimes the disabled parts failed QC but the numbers that fail QC but are still usable are not high enough for the high volume parts. Really it is just a way to do differential pricing. Some people will pay $500, some only $100 while the part only cost $25 to make. The way to maximize profits it sell to both, and find a way to justify the price difference.
neogodless 10y ago
The other thing with "decoy pricing" is that you "throw away" the cheapest option without proper research. The Core i3-6320 is about $60-70 cheaper than the i5-6600k, but on applications that don't benefit (sufficiently) from multiple cores, it can perform nearly as well. Anecdotally, friends building PCs always compare i5 and i7 and never consider the i3, but for their real world uses (many games!) it would be just perfect (and the savings could be thrown at the video card where it'd make more of a difference.)
- usrusr 10y ago
  The expected "close enough to state of the art" lifetime of hardware is now so long that you can write off the premium paid for extra cores over many years. Would i be willing to pay 35$ extra per additional core if I knew I would want to replace the hardware within two years anyway? Questionable. But when hardware lasts half a decade? The premium per core per year becomes irresistably low. The i7-2600k will soon have it's sixth birthday...
  - neogodless 10y ago
    I don't disagree. The difference between a $160 6320 and $330 6700 is only $170, and 8 years (how old my Phenom II is...) reduces that cost to barely over $20/year. However, whether "the core is going to be fully utilized" is another question. If you only ever need 2 cores, it is wasted money, plus, if your focus is on gaming, and your budget requires you to make choices based on right now, the extra $170 can be the difference between getting a Radeon 480 or a Geforce 1070. (Since I hope my next build lasts another 8 years, I'll probably "pad" my build with an i5... I've fallen into the trap!)

by Sammi 10y ago

mrmondo 10y ago

Is the cache size and turbo boost the same though?

legodt 10y ago

It's also much more expensive to produce an i7. i7 are near perfect chips and are able to run higher clock rate efficiently and safely while i5s are more "standard" and have their performance clamped down to what they can safely handle. There are less i7 chips rolling off the lines, which increases their price. Hopefully somebody who knows more about this than me can jump in and fill in the blanks here. EDIT: I communicated my point poorly and the comments below mine explain this is much clearer terms

dragontamer 10y ago
I don't know Intel's specifics, but often there's only a few chips that a manufacturer makes... and depending on the Quality / testing of the chips... the chips are binned into different categories. As a hypothetical example (I'm not 100% sure if this is how Intel does things), and i5 could just be an i7 except it couldn't handle the higher clock rate. So instead of throwing away a chip that's limited in clock... Intel will sell the chip as an i5. Or perhaps in another chip, the hyperthreading portion got borked because of a piece of dust landed in the lithography. So instead of selling it as an i7, the hyperthreading portion is fused off and the chip is sold as an i5.
- legodt 10y ago
  You're the guy who knew more and filled in the blanks! I am super fascinated by this topic (and an outsider). Do you have any specific examples or situations that you know of this happening? The hypothetical you gave above was awesome and now I'm curious for more.
  - dragontamer 10y ago
    AMD's Tricore vs Quadcore... something (I think Phentoms??) were definitely this. Some Tricores were able to turn into quad-cores with some firmware hacking. The IBM-Cell in the PS3 was a different approach to the same problem. The Cell was specified as 7-SPUs and 1-CPU, but in actuality... the manufacturing process made 8-SPUs and 1-CPU. IBM assumed that one of the SPUs would fail during manufacturing, so they only promised to deliver 7 of them per PS3. You can literally see the 8 SPUs: https://upload.wikimedia.org/wikipedia/commons/e/e0/Cell-Processor.jpg https://upload.wikimedia.org/wikipedia/commons/e/e0/Cell-Pro... There's lots of ways to approach the problem. Manufacturing is an imperfect process: not everything is made identically. So the manufacturers have to figure out how to test for differences and... if necessary... sell the same "manufactured" chip in different bins.
    - legodt 10y ago
      Thanks for taking the time to go further on this and link that image, very cool stuff.
    - Fnoord 10y ago
      > AMD's Tricore vs Quadcore... something (I think Phentoms??) Phenom. https://en.wikipedia.org/wiki/AMD_Phenom https://en.wikipedia.org/wiki/AMD_Phenom https://en.wikipedia.org/wiki/Phenom_II https://en.wikipedia.org/wiki/Phenom_II Not all the hardware of Cell on PS3 was available if you run the official Linux port. Which was later blatantly removed.
mohaine 10y ago
Historically, I don't think it has worked like this for Intel. It costs way more to have multiple designs so they are all pretty much the same few chips with the packaging changed to disable parts. Sometimes the disabled parts failed QC but the numbers that fail QC but are still usable are not high enough for the high volume parts. Really it is just a way to do differential pricing. Some people will pay $500, some only $100 while the part only cost $25 to make. The way to maximize profits it sell to both, and find a way to justify the price difference.

neogodless 10y ago

The other thing with "decoy pricing" is that you "throw away" the cheapest option without proper research. The Core i3-6320 is about $60-70 cheaper than the i5-6600k, but on applications that don't benefit (sufficiently) from multiple cores, it can perform nearly as well. Anecdotally, friends building PCs always compare i5 and i7 and never consider the i3, but for their real world uses (many games!) it would be just perfect (and the savings could be thrown at the video card where it'd make more of a difference.)

usrusr 10y ago
The expected "close enough to state of the art" lifetime of hardware is now so long that you can write off the premium paid for extra cores over many years. Would i be willing to pay 35$ extra per additional core if I knew I would want to replace the hardware within two years anyway? Questionable. But when hardware lasts half a decade? The premium per core per year becomes irresistably low. The i7-2600k will soon have it's sixth birthday...
- neogodless 10y ago
  I don't disagree. The difference between a $160 6320 and $330 6700 is only $170, and 8 years (how old my Phenom II is...) reduces that cost to barely over $20/year. However, whether "the core is going to be fully utilized" is another question. If you only ever need 2 cores, it is wasted money, plus, if your focus is on gaming, and your budget requires you to make choices based on right now, the extra $170 can be the difference between getting a Radeon 480 or a Geforce 1070. (Since I hope my next build lasts another 8 years, I'll probably "pad" my build with an i5... I've fallen into the trap!)