32GB iPhone 7 significantly slower than more expensive versions, tests show | Hacker News Reader

32GB iPhone 7 significantly slower than more expensive versions, tests show

theguardian.com

105 pointsjonathansizz44 comments

My suspicion is that it has to do with the test and the SLC cache. In the iPhone 7, most of the flash is TLC, but a portion of the flash is configured as much faster (for writes) SLC. The cache buffers a certain amount of writes, later transferring them to TLC. On a bigger drive this cache is bigger. So if the test fits into SLC cache on the bigger phone but falls out of it on the smaller phone, that (combined with lower write parallelism with fewer flash chips) would explain the write delta.

Thank you for your much more in depth explanation then my very simplistic answer.

These tests churn GBs of data (necessary given how fast flash is), rendering the cache largely irrelevant. As I mentioned elsewhere, it is incredibly unlikely that parallelism plays a part (and has never been the case in prior devices, nor is it the case with the vast majority of SSDs. Anyone blindly buying larger for more parallelism is very likely to be disappointed). Different vendors make their memory solutions, and there are huge variations in options. We've seen this across a single model of a set size when two different vendors provide the storage.

In the end it really won't make a difference for real world use.

That would also explain the much smaller delta between the big and small phones on the sustained write test.

More troublesome than the slower SSD speeds is the lower quality Intel Modem compared with the Qualcomm Modem -- at least in large cities where there are large buildings that block signal. Meanwhile, the Samsung S7 has the Qualcomm Modem (MDM 9645M) with 4 antennas that allow for 4x4 MIMO, 256 QAM DL, EVS (Enhanced voice services). On the Samsung phone the 4x4 MIMO is now turned on as is the EVS (Ultra HD voice), the later which provides higher quality voice and operable at lower signal strength than current HD voice.

For those of us the own the Verizon/Sprint version, I wish that Apple would at least match the capabilities of the Samsung S7 that shipped 6 months before the iPhone 7. The difference is the quality of the voice and the ability to communicate when signals are weaker.

The Verizon/Sprint version has the Qualcomm modem. Are you saying that even with Qualcomm there's a noticeable difference between the iPhone and the S7?

Yes, the Samsung is better.

Important is not only the baseband modem, the Qualcomm MDM 9645M, but also the RF Front End, the number of antennas, and the antenna design.

Both units have the Qualcomm X12 MDM9645M baseband modem and two transceivers, Qualcomm WTR3925 and WTR4905.

But the iPhone has only 2 antennas and only able to support 4x2 MIMO while the Samsung has 4 antennas does currently support the 4x4 MIMO.

The 256 QAM DL/ 64 QAM UL can be turned on with a firmware upgrade in both phones. Neither phone has it turned on at this time.

The EVS -- Enhanced Voice Services offers significantly improved voice quality over even the HD voice with an improved codec and a better packet communications layer.

Samsung has EVS turned on, the iPhone does not.

The 4x4 MIMO, 256 QAM, and EVS are also contingent on the carriers implementing these features, but these are available on T-mobile and will soon be available on Verizon.

I am disappointed that Apple did not do at least as good of a job as Samsung which provides the 4x4 MIMO, 256 QAM, and EVS.

The 4x4 MIMO and 256 QAM are important not only for better signal quality but also a better use of spectrum, which in large cities is going to be an issue in the (near) future.

One other feature to look out for is Band 66 support which covers the newly purchased AWS-3 spectrum (US). The LG V20 phone coming out at the end of this month will be the first phone to support band 66. In this sense, both the Samsung phone and the iPhone are already obsolete.

voice?! what decade are you living in?

We could also just link to the source: http://cellularinsights.com/iphone7/

CellularInsights was a source. My undergrad is EE/CS and I studied digital comms as well as meet Qualcomm people mobile health summit and other health computer conferences.

Sources included iFixit which discussed the chips involved (but neglected to mention whether there were 2 or 4 antennas in iPhone 7 which cellular insights did provide), Qualcomm data sheets, Tmobile and Verizon press releases, fiercewireless, howardforums, Enhanced Voice Services (EVS) specs and datasheets from Ericcson, Nokia, and others.

I was also surprised to see the iPhone 7 doesn't do 4x4 MIMO/256 QAM seeing how many operators are pushing it as their solution for LTE congestion (Docomo just announced their fall lineup of phones, T-Mobile in the US, Telstra in AU...)

Verizon is adding 4x4 MIMO and I expect all of the US providers will be doing so because spectrum is a scarce and very expensive resource and at least in the case of Verizon, use is increasing substantially.

While the 4x4 MIMO requires the 4 antennas, the 256 QAM can be provided by a firmware upgrade without the 4 antennas.

I understand the bandwidth issues with low signal strength, but what are you basing a reduction in voice quality on?

Well, I'm specifically referring to VoLTE. The towers have more powerful transmitters than the handsets, so a user might hear voice just fine, but the person on the other end can hear breaking up voice which is precisely what happened to me in Manhattan on Verizon prior to the 10.03 update with the 1.00.05 modem firmware upgrade. I was being switched to a tower that had only -124 dBm.

The Enhanced Voice Services spec also mentions working at lower signal strength.

doesnt matter because Intel modem is practically free. Intel is subsidizing it at the Atom levels from few years back, in other words Intel is paying Apple for the privilege.

A slowdown is to be expected with Solid State Disks; as smaller SSDs are slower then larger ones. Simply because larger ones have more NAND chips and are therefore able to write to more locations at once.

https://superuser.com/questions/977080/does-a-large-ssd-perf...

that explains the 25-30% slower read speed, it does not explain the nearly 10 times slower write speed, there must be something else going on

It explains write speed differences, see http://www.anandtech.com/show/8747/samsung-ssd-850-evo-revie... for example, bigger drives support faster writes. Though 10 times slower speed should be more than what is explainable by that.

You bring up a good point a 10x slowdown is quite dramatic. I have edited my original post to make it sound like less NAND chips in the SDD isn't the only issue.

I would think it is just them buying cheaper 32GB drives from another manufacture. Just like different USB flash drives have varying performance depending on who makes them.

From the looks of it, my 7+ shipped with the Intel modem, and I can definitely see a drop in network strength when compared to my wife's iPhone 6. This is particularly worse when traveling, as the phone barely manages handoff properly.

I also noticed strange interference noise when using my earphones during my everyday commute. This seems to have been fixed by the recent update (10.0.3) though.

That's crazy! I noticed this when I got the iPhone 6+. When I'm on the train I have to put it in airplane mode and take it back out for it to find the nearest tower sometimes. I thought this was just a power saving technique by Apple (maybe if it doesn't poll as much it doesn't use as much battery?) but it's obnoxious as hell if you're a commuter.

Indeed, trying to find signal when there is no signal or when it's too weak is big drain on the battery. So when the iPhone thinks there's no signal, it's going to throttle its searches a bit to avoid draining too much power.

In my experience, you can often get it to check again by locking the screen and then unlocking it again. Usually I only have to resort to going to airplane mode and back when the phone does have signal but it can't get reliable data (I'm assuming that going through airplane mode may cause it to switch towers).

I'm curious how you can tell and if you bought a UK/EU or US version?

The moment I heard that modems were different between service provider models, I suspected that trouble like this may arise from them more band-restricted model of the two. It's one of the reasons I waited for the SIM-free/international model to become available before buying.

I think band/antenna differences between models should be much, much more visible. Right now this info can only be found on the tech specs page of Apple's iPhone site, but it really should be prominently visible on one of the feature pages too. Otherwise you're going to have a bunch of AT&T/Sprint subscribers being unpleasantly surprised when their $700+ "unlocked" flagship phone is almost useless overseas.

> Otherwise you're going to have a bunch of AT&T/Sprint subscribers being unpleasantly surprised when their $700+ "unlocked" flagship phone is almost useless overseas

This was a dealbreaker in the dualband/quadband days, an issue in the early UMTS days (when there were phones without 2100), but these days even the "band restricted" models mean you're just not going to get extended range bands, far from "useless overseas".

Granted, but it's still disappointing and less than I'd expect from a device costing so much.

title omission: "... in benchmarks".

In the real world, the flash speed difference is rather insignificant. I don't copy around huge 4K movies on my phone very often.

I think this really depends on how long you are expecting to use your phone. Presently the iPhone 7 feels unnecessarily fast, but in 2-4 years when more data is consumed and operating systems are more taxing, I may care more about those difference.

"unnecessarily fast"

I'm curious what you mean by this. No snark, genuinely curious.

Perhaps he means that the speed difference between the 7 and the 6 is almost unnoticeable, because everything that he does was near instant before?

That is basically my experience with modern Android phones at this point, and they aren't even as fast as the iPhone.

How can something feel unnecessarily fast? It may be unnecessarily fast but to me tech never feels fast enough. Unless it would respond before I do something perhaps... I'd like lag to approach zero to be honest.

but to me tech never feels fast enough

Because of programmers and Hardin's "Tragedy of the Commons." Coders will always use the computation, memory, and bandwidth resources that are there. "If I just use a little more, it benefits my app, but it hurts everyone else just incrementally." Everyone makes the same calculation, and voila, the machine that's 2X faster feels just as slow. It's the same reason why building more highways just results in more people stuck in slow traffic.

IF you only have 32GB of storage you won't be doing that anyhow.

On some level it doesn't really matter, it stinks but it doesn't matter.

That said it might affect the camera performance in the long run, but then again if you are going to film 4K and take tons of RAW photos get the bigger storage since it's not expandable.

Depends on your use case for your phone - I usually copy 20-30 GB of videos to my iPhone 6S(using VLC) on a fairly frequent basis - for some reason it's my primary way of watching TV shows. The saving grace here, is that with only 32 GB, there is a pretty hard limit to how much you can copy before you just run out of space.

Did they run these tests again AFTER the 10.0.3 patch that was supposed to significantly improve Verizon service for many people (back to at least where it was on a 6s)?

After reading both of the Guardian's sources here and seeing what their testing methodology was, I think I'll withhold judgement until someone with a more solid reputation does the testing.

Quite a few users in the comment thread over on GSMArena are posting testing results for their 32GB iPhone 7 which are much faster than what GSMArena is claiming. Judge for yourself:

http://www.gsmarena.com/the_32gb_iphone_7_plus_uses_a_substa...

Edit: one more note. GSMArena's article on this was posted on October 7; too early for the latest iOS updates to have been used in testing.

Missing from the title: «…significantly slower on network access than…»

The 128GB iPhone 7 wrote to memory at 341Mbps, but the 32GB iPhone 7 was over eight times slower at just 42Mbps.

Slow write speeds are the hallmark of being too much of a cheapskate when buying SSDs. 42Mbps would be miserably slow for a laptop SSD. Buying such a slow SSD is the kind of mistake I'd expect from a non-savvy consumer.

Then again, how much data is being written to an iPhone's SSD per second on average?

Two possible reasons for shower performance:

1. 32GB capacity comes with lower SLC cache 2. 32 GB storage has fewer dies/planes in NAND reducing parallelism

Gotta maintain that ~40% gross profit margin somehow.

... but it's still more than fast enough for any process which executes on the phone.

Wait until iOS 12 :)

Except for writing photos and videos to disk, as stated in the article.

It's not the CPU that is the problem, it's the flash storage and the cellular modem. Two things which can definitely impact users on a day-to-day basis.

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