Apple iPhone 6 Benchmarks show Difference Between TLC NAND and MLC Flash Memories

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Apple iPhone 6 benchmarkOne of the major upgrades with this year’s iPhone 6 and iPhone 6 Plus has been the internal storage capacity. While last year’s iPhone 5s topped out at 64GB, the iPhone 6 and iPhone 6 Plus have a higher 128GB option. The size isn’t the only difference though, Apple has also moved to TLC NAND flash storage on select 64 and 128GB iPhone 6 and 6 Plus models this year. KBench decided to run benchmarks and find out the exact differences between the two types of flash memory.

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The results of the benchmark comparison are quite surprising. KBench conducted two tests: Zero Filling and Random Data. The first test overwrites all data stored in the memory with null values (0x00). All data that is stored on the flash memory is deleted permanently, making it impossible to recover the data. A 3.4GB block of data was written on to the memory for this test. The MLC flash memory managed an average transfer rate of around 75MB/s while TLC flash managed to perform much better initially, with transfer speeds reaching 200 MB/s, but the rate dropped to 40MB/s after 800MB data had been transferred. MLC flash was actually slightly faster during the final stage of the test, with transfer speeds hovering between 65 and 75MB/s.

In the Random Data test, MLC outperformed the TLC flash memory consistently. TLC managed transfer speeds of around 3MB/s throughout the test while MLC started with 2.9 MB/s and shot up to 15.7 MB/s near the end. It also turns out that the TLC memory usually has higher RAM usage than MLC NAND. In the tests conducted by KBench, the iPhone 6 with TLC flash memory had 232.8MB inactive memory, while the one with MLC flash had only 109.9MB memory inactive.

So it isn’t just the speed difference, but also higher memory utilization that makes TLC flash a clearly inferior alternative to the more popular MLC flash memory that Apple has used on its iPhones in the past. Recent rumors suggested that Apple could discontinue the use of TLC memory in its products, while we’re not sure how accurate the info is, we do hope Apple will go back to MLC Flash for future iPhones.

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  1. I have asked Apple to replace my iPhone 6 Plus 128GB three times because of this defective memory component TLC NAND Flash. And they did replace it three times without arguing! This is the 4th replacement in my hands in a couple of months!

    You can see if you have the defective TLC NAND Flash or the non-defective MLC NAND Flash just using the app

    I suggest you all to go to your Apple Store and simply say: “my iPhone 6 reboots randomly 5 times a day and my apps (always mention Apple apps as Pages, Numbers, Safari) crash randomly 10 times a day. I bought the costliest existing iPhone specifically to work out of the office on those apps and with these reboots and crashes I can’t get any work done.” Then you will see how they will immediately replace it with a new one as they keep doing with me.

    The reason why they replace them without arguing is that they perfectly know the problem even though they will never admit it to you. Admitting it to you would mean admitting it publicly and that would mean being forced to start a dramatically costly mass replacement worldwide. Even though they will never admit it to you they still will always replace it because they are afraid that you will sue them therefore publicly revealing the problem with an even worst damaging publicity.

    If you even only mention the name TLC NAND Flash defective memory component (that was stopped being used by Apple in favor of MLC six weeks after the release of the iPhone 6 and 6 Plus because of the discovery of them causing random reboots and crashes) every Apple employee is instructed to reply to you that if that information is not on the Apple webpage it is an untrue rumor (and I always reply them that Apple not only excludes false rumors from its webpage but obviously also truths that are dramatically inconvenient for them, right?).

    In my case I have not been lucky because this last replacement has a TLC from Toshiba, the previous replacement had the TLC from Sandisk and the previous replacement had a TLC as well (I don’t remember the manufacturer), the previous iPhone, which was the original one, was working perfectly and I replaced it for a completely different reason in a moment in which I had no idea about the existence of these defective components, otherwise I would’ve realized how lucky I was and I would’ve kept it.

    I don’t care whether or not they admit it during the replacement. What I care and what I tell them (and what you should also tell them when they replace it) is that I will keep scheduling my Apple Genius appointment every Monday and make them replace my iPhone 6+ every week until they give me one that doesn’t reboot/crashes no matter what the real cause is. In other words until they give me one with the non-defective “MLC” NAND FLASH memory component. You should do the same.