Is 1tb Drive Faster than 2tb Drive?

Discussion in 'iMac' started by Trvlngnrs, Jul 6, 2012.

  1. Trvlngnrs macrumors 6502

    Trvlngnrs

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    Jun 8, 2010
    #1
    I've read a few times on MacRumors that the speed difference between a 500gb 5600 rpm drive is not "much" slower than a 1tb 7200 rpm drive This is attributed to the smaller platter size, causing the "reader" to access the info quicker.

    I'm considering an iMac and was wondering if this logic held true with the 1tb versus 2tb drives?

    Thanks for your input,
    Trvlngnrs
     
  2. jav6454 macrumors P6

    jav6454

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    #2
    HDD read speeds depend on two things:

    1. RPMs
    2. Platter Densities

    Higher RPMs mean faster spinning platters which mean faster access times. Moreover more platter densities mean less mechanical failure and less time to determine in which platter is the information on.
     
  3. Chippy99 macrumors 6502a

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    #3
    And the third thing. Which you forgot. Seek times. Fast seeks = lower access times, high IOPS and higher random access throughput.
     
  4. Puevlo macrumors 6502a

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    #4
    I think you're mistaken. The 1TB and 2TB refer to the capacity not the speed.
     
  5. gingataff macrumors newbie

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    May 13, 2012
    #5
    I think the OP knows the difference in terms of capacity but is wondering if a 2TB has a physically larger platter which will decrease the read speed.
     
  6. gnasher729, Jul 7, 2012
    Last edited: Jul 7, 2012

    gnasher729 macrumors P6

    gnasher729

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    #6
    And the fourth thing. How full is the disk? Every disk can fit more data on the outer tracks than on the inner tracks, which means the read speed can be down to about 40% to 45% on the inner tracks. An empty 1 TB and 2 TB hard drive will have the same speed if everything else is equal, but if you fill them each with 800 GB, then one is 80% full and the other is only 40% full and will run faster because of that.


    Whoever said that has got it completely wrong. It's exactly the opposite. The smaller capacity and larger capacity drive have the same size; with the smaller capacity the information has to be further apart and accessing it takes longer. Plus the effect that drives get slower when they are full. And if the smaller drive is smaller because it is older technology and lower density, that makes it slower as well.
     
  7. Trvlngnrs thread starter macrumors 6502

    Trvlngnrs

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    Jun 8, 2010
    #7
    Ok let's see if I'm understanding.

    It's not that the platters are a different physical size, because they are the same size. It's that the information that is being accessed is "squished together" aka "denser" on the smaller drive so the reader doesn't have to travel as much to read the data. In addition, on a smaller drive the info will be stored on the outer portion of the drive sooner, which also decreases access time because there is more hard drive passing under the "reader".

    When an Apple device is writing to a hard drive, is the info stored moving from the center to the edges, or is it more randomly stored? Seems like Windows would do it more randomly, that's why it needs to be defragged.

    Does anyone know of reviews of the 1tb versus the 2tb?


    Trvlngnrs
     
  8. ivoruest macrumors 6502

    ivoruest

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    #8
    There is a lot more than capacity and disk speed that will make any HDD slower or faster than others.

    -Density
    -Rotational Speed
    -Caching
    -Disk Usage
    -Data integration (consistency)
    -Link speed

    Some are not as important as others but all added up in a bad situation may make even the fastest HDD on earth as slow as an ancient disk.
     
  9. gnasher729 macrumors P6

    gnasher729

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    Nov 25, 2005
    #9
    No, it is not denser on the lower capacity drive. It is denser on the higher capacity drive.

    Build two cinemas of the same size, but put 500 (large) chairs in the first and 1000 (smaller) chairs in the second. It takes you the same time to walk along a row, but in the first cinema you pass maybe 25 people, and in the second cinema you pass 50. 200 people take maybe 8 rows in the first and 4 rows in the second cinema, so going from the first to the last of 200 persons, you need to pass 8 rows vs. 4 rows.
     
  10. Chippy99 macrumors 6502a

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    Apr 28, 2012
    #10
    That's a fair point actually. There are lots of parameters aren't there. The other thing is the drive electronics (as in IDE = Integrated Drive Electronics) are all proprietary and have different algorithms and are more or less efficient for different use-cases.

    i.e. you can take two 1GB drives with the same physical characteristics (number of platters, heads, rotational speed and even the access times), fill them with the same data, and they will *STILL* not perform identically if one is a Hitachi and the other a Seagate.
     
  11. jav6454 macrumors P6

    jav6454

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    #11
    Seek times depend on the speed of the drive and density of the platters, so there goes your argument. Try harder next time.
     
  12. Chippy99 macrumors 6502a

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    Apr 28, 2012
    #12
    Actually, I don't have to try harder because I am correct and you are wrong.

    Yes, seek times are affected by data density. But they are not directly affected by the rotational speed - that affects the rotational latency and overall access times, not the seek times.

    And the seek times are also a function of the drive head armature (ballistics etc) and how the manufacturer has implemented it, which is my point.

    You completely ignored this latter point (as you do again above), which is why you are wrong again. It's best to get your facts straight before making "smart" comments or you can end up looking a bit foolish.
     
  13. jav6454 macrumors P6

    jav6454

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    #13
    You said it...


    The rest is also part of it, but data density is primordial.
     
  14. Chippy99, Jul 9, 2012
    Last edited: Jul 9, 2012

    Chippy99 macrumors 6502a

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    Apr 28, 2012
    #14
    You said:

    "HDD read speeds depend on two things:
    RPMs
    Platter Densities"

    I pointed out that you are wrong because seek times are also a factor. So your basic premise above is fundamentally wrong. You can try to worm out of it if you like, but that's the facts.

    HDD speeds DO NOT only depend on rotational speed and data density.
     
  15. Bear macrumors G3

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    #15
    An important addition to that list is the number of platters in the drive.

    As others have said you need to look at all the specifications for the drives in question. And then you would still need to test since the controller for the drives will impact performance.

    Also "not much slower" is such a relative term. The performance of the disk will affect your computer differently depending on what you are using your computer for.

    Also, think of how big you would want that disk to be in 2 to 3 years (or more) since you will probably be using it that long.
     
  16. ivoruest macrumors 6502

    ivoruest

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    #16
    I guess I forgot the ETC...:D Thanks for the complementary info.
     

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