Examining reports of slow write speeds on the 32GB iPhone 7

Reports are going around of late that the 32GB iPhone 7 has demonstrably slower write performance than its larger siblings. Under the provocative title "iPhone 7 – What Apple Doesn't Want You To Know," YouTuber Unbox Therapy has shown that the 32GB version of the phone has much slower write performance than the 128GB version. He concludes that Apple "probably went a little bit chintzier on the lower-capacity models in terms of the quality or caliber" of the devices' storage, leading to the performance difference.

When I saw these results, I immediately surmised that the write performance of the storage subsystem in the iPhone 7 is limited by the number of dies hooked up to the device's storage controller. In general, we know that the more flash devices one can hook up to a controller, the more performance one can extract from solid-state storage, at least to a point.

It appears that hunch could be correct. Thanks to the fearless folks at iFixit and Chipworks, we know some of the details of the iPhone's storage subsystem. At least some iPhone 7s use a 32GB SK Hynix H23QEG8VG2ACS storage chip. According to SK Hynix's data sheet, that chip contains four flash devices inside one package, for a total of 256Gb—or 32GB—of raw storage space. At least some 128GB versions of the iPhone 7 use the SK Hynix H23Q1T8QK2MYS chip, according to Chipworks, and that part has eight dies in a package. Chipworks also says the 256GB iPhone 7 uses an eight-die package with Toshiba 3D NAND inside.

We know next to nothing about Apple's storage controller in the iPhone 7, but it seems possible the controller isn't able to saturate all of its channels when it's paired with the 32GB SK Hynix chip. If that's true, the drop in write performance is regrettable, and it has unfortunate implications for moving data onto the device. Still, the difference seems to be a result of well-understood limitations in flash storage architectures, not because Apple "went a little bit chintzier in terms of the quality or caliber" of the 32GB phone's storage.

Comments closed
    • GTVic
    • 3 years ago

    Cell phone users always have interesting reasons why their phones don’t work. Usually its not their fault.

    • ColeLT1
    • 3 years ago

    82.1 write / 779 read on my 32gb iPhone7

    edit:
    87 write / 181 read on 64gb iPhone 6+ (my old phone)
    38.3 write / 515 read on 32gb iPhone 6s (just unboxed)

    • torquer
    • 3 years ago

    I hate 90% of YouTube. Yet, I cannot look away…

    • bfar
    • 3 years ago

    Why are these YouTubers all really hard to watch for more than 5 seconds?

      • The Egg
      • 3 years ago

      You made it 5 seconds? I didn’t get past the picture.

      • tipoo
      • 3 years ago

      Because they take something that could be explained in 30 seconds but stretch it out to rack up that sweet sweet adsense revenue.

      Also the hat.

    • tipoo
    • 3 years ago

    Incidentally, the read speed of the 32GB is still higher than any capacity of any other non-iPhone phone out there.

    I can see why people want Apple to be more clear with this, but they never advertised their impressive NAND speed to start with as far as I know. And the high read speeds will make it feel fast opening and resuming things.

    • davidbowser
    • 3 years ago

    If they are going to go after Apple for something, at least make it something that is actually “broken”, like the whole antenna BS several years ago. THAT was worthy of complaint.

    From the technical/objective perspective, this is just, “Hey! The cheaper version of this thing isn’t as good/fast/magical as the more expensive version of this thing!”

    • watzupken
    • 3 years ago

    It’s a known problem, though people that are not tech savvy may not be aware. Again, people who are not tech savvy likely won’t find it a big problem anyway.

    • Mad_Dane
    • 3 years ago

    Congratulations, they discovered how SSD’s works…

      • derFunkenstein
      • 3 years ago

      Except he didn’t, apparently.

    • uni-mitation
    • 3 years ago

    Meanwhile it doesn’t suddenly combusts then the masses will buy it!

    Uni-mitation

    • The Egg
    • 3 years ago

    I recently snagged the 32GB version of the iPad Air 2, which was a brand new SKU, just released at the same time as the IP7.

    I think the likelihood that they used the same setup/NAND chips for this new SKU is probably pretty high.

      • drkskwlkr
      • 3 years ago

      …and?

        • the
        • 3 years ago

        The implication being that there will be some 32 GB iPad Air 2s that have noticeably lower write performance compared to the original 32 GB models. Of course this needs outside testing for verification.

        Changing up the flash mid-cycle has caused problems for [url=https://techreport.com/review/26664/alleged-bait-and-switch-tactics-spur-kingston-pny-ssd-boycott<]SSD manufacturers before in the past.[/url<] However, Apple never advertised the read/write speed of its flash and thus any change like this will have less of an impact in terms of adhering to advertising.

    • Redocbew
    • 3 years ago

    When I see “YouTuber” I think “Potato”.

      • Wonders
      • 3 years ago

      YouTuber! Potato!
      YouTuber! Potato!

    • Wirko
    • 3 years ago

    You’re buying cheap wrong!

    • tacitust
    • 3 years ago

    The difference between proving something happens and knowing why it happens. He also didn’t explain why if the write speed was 8-times slower, the movie transfer was only twice as slow which, if I were a regular iPhone user, I would definitely want to know.

    • DPete27
    • 3 years ago

    Flash storage 101 people…..

    • Voldenuit
    • 3 years ago

    [quote<]not because Apple "went a little bit chintzier in terms of the quality or caliber" of the 32GB phone's storage.[/quote<] Apple [s<]cheaped out[/s<] is courageous by not offering a 64 GB model as the baseline, in line with the flash controller, because it wants to charge a ridiculous premium for the 128 GB model.

      • nico1982
      • 3 years ago

      64 GB as baseline would be fearless, 32 is courageous enough 😛

      • tay
      • 3 years ago

      The premium is no higher than Samsung or Google. And the phones are better. Not seeing the problem.

      • derFunkenstein
      • 3 years ago

      It’s [url=https://madeby.google.com/phone/<]good enough for Google[/url<], right? /insert another rant about how every flagship is an exercise in compromise, which is utter bull shit considering the price

    • derFunkenstein
    • 3 years ago

    But if a YouTuber says it, it’s gotta be true, amirite? I mean what do iBrokeIt and Chipwerkz know?

      • tay
      • 3 years ago

      Gah – don’t even link the Youtube. I appreciate TR’s take on the problem.

        • derFunkenstein
        • 3 years ago

        I understand why Jeff linked it (gotta cite your source), but I certainly won’t click it and give that turd any additional video views.

      • nanoflower
      • 3 years ago

      Ultimately it doesn’t matter why the write speed is slower to the average customer. Just the fact that it is slower is the important fact. While it would be great if everyone got the facts right people like this guy are just technically savvy enough to come up with a plausible explanation which is enough for him to move forward with a video. That does get a lot of people talking about it and can lead to more technically savvy people investigating and finding the real cause as in this case. I’m not sure they (the truly technically knowledgeable) would have checked out the write speed without a video like this to jumpstart the discussion, and would the discussion have spread without the blame being placed on Apple?

        • derFunkenstein
        • 3 years ago

        Non-techies will listen to anybody who represents themselves as techy, even if those who claim it are not particularly tech-literate. We all know what’s next: some rabid, drooling Neanderthals are going to watch this video and take the inarticulate speculation of its creator as fact. Pretty soon enough rumors of how Apple “cheaped out on the 32GB iPhone” are going to float around. Early buyers will be all upset because while their phone is fine and performs fine for them, they think they’re getting screwed. Basically the GeForce GTX 970 all over again. It works fine, it performs fine, but people will feel “unjustly screwed” because that’s their default nature.

        edit: run-on sentence

          • brucethemoose
          • 3 years ago

          Thing is, 99% of iPhone buyers couldn’t care less. Apple isn’t stupid: if this made a big enough difference for the average user to notice, they would’ve used 8 dies.

          Graphics cards are a bit different, as they’re bought almost exclusively for their performance. That particular issue only shows its head upon breaking the 3.5GB threshold, and people were upset that they didn’t know that before buying, even if most did over-react.

      • EzioAs
      • 3 years ago

      What do you have against iFixit?

        • derFunkenstein
        • 3 years ago

        Nothing. It’s a valuable resource. You missed my sarcastic support of unsubstantiated claims.

          • EzioAs
          • 3 years ago

          Oh, sorry. 😛

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