Runtime shootout : Dual SDXC, mSata, SDXC and Original Hard Drive

Runtime shootout : Dual SDXC, mSata, SDXC and Original Hard Drive

So it is finally time for a quick write up comparing the various storage options for the iPod.

The test is pretty simple – load up each storage option with the same music, hit play and see how long it takes for the iPod to shutdown. While in actual use the runtimes will be shorter, it still provides a very useful comparison of the different storage mediums.

Test was conducted on the 7.5g iPod Classic, originally came with 160Gb hard drive. I chose this as the original 160Gb hard drive is very efficient as far as spinning platter disks go and the 7.5g itself is the most efficient of this generation of iPods.

Storage 160Gb, 256Gb, 500Gb, 1Tb

Storage 160Gb, 256Gb, 500Gb, 1Tb

iFlash - The Adapters

The Adapters

Equipment list :-

Storage options :-

  • 160Gb HDD OEM (Toshiba MK1634GAL)
  • 256Gb SDXC PNY
  • 512Gb Dual SDXC (Using 256Gb PNY U1 and 256Gb Kingston SDA10/256Gb)
  • 500Gb mSata Samsung 840EVO
  • 1Tb mSata Samsung 840EVO

After installation, iTunes was used to restore and sync the iPod using the same 36000 tracks, 220Gb collection – The HDD being smaller than the others only sync’d 150Gb’s worth of music of around 24000 tracks. The 1Tb was synced up with an extra lossless heavy collection to take it up to 45000 tracks 930Gb in size.

HDD 160Gb About Screen

HDD 160Gb About Screen

SDXC 256Gb About Screen

SDXC 256Gb About Screen

mSata 500Gb About Screen

mSata 500Gb About Screen

mSata 1Tb About Screen

mSata 1Tb About Screen

Two playlists were created one comprised of 320Kbps MP3 tracks, the other Lossless m4a tracks. I decided to do this as the frequency that the iPod reads from the storage device varies depending on bitrate of the music – e.g. with 320Kbps MP3’s the drive is read every 10 to 12 minutes, where as with a high bitrate lossless m4a the drive is read every 2 to 3 minutes. Very dramatic difference which will have a huge impact on runtime results.


I ran some drive benchmarking tests to get a feel for the read and write speeds of each storage medium. As this was a test from computer to iPod, the results would ultimately be limited to the maximum the USB2.0 bus would allow. Interesting none the less.

HDD 160Gb Benchmark

HDD 160Gb

SDXC 256Gb Benchmark

SDXC 256Gb

mSata 500Gb Benchmark

mSata 500Gb

mSata 1Tb Benchmark

mSata 1Tb

Dual 512Gb (2x 256Gb SDXC)

Dual 512Gb (2x 256Gb SDXC)

The mSata and HDD hit the USB2.0 limits with approx. 22Mb/s read and more importantly for syncing 32Mb/s writes to the iPod. The SDXC/DUAL trails here at approx. 23Mb/s writes and 14Mb/s reads – this is expected as the SD-CF Adapter is spec’d for 25Mb/s transfer rates. The DUAL shows a 1Mb/s improvement on the read speed, this is down to the improved speed of the Kingston card over the PNY.

Lets see what this does for actual iPod use by measuring boot time and how long each storage medium takes to fill the read-ahead buffer in the iPod, this will demonstrate the access times and user experience when scrolling and searching through long track lists.

Storage Access Times

Storage Access Times

Interestingly, it looks like the storage read speed does not impact the boot time as much as you would expect. Considering the mSata read speeds are much faster than the SDXC. The SDXC only takes 2 seconds longer to boot – The overriding factor is the time the iPod takes to parse through the iTunes database of 36000 tracks in the case of the SDXC and mSata drive, still the HDD takes close to 50seconds to boot while having only 24000 tracks to parse. As a reference, freshly restored iPod boots up in around 24 seconds.

While the SDXC & DUAL have the slowest raw transfer speeds, they are hands down winners of the Read-ahead and access times test. HDD is the slowest at 7.5 seconds which was to be expected as it takes over 1 second for the drive to spin-up before actually reading any data. The mSata comes in 2nd with a time of 6.7 seconds this maybe surprising but the SATA bus actually takes some time to handshake and negotiate the link from powerup. The SD-CF Adapter is designed to be ready for access in under 100mS, and the SDXC cards have virtually instant access times – which result in a blistering 5.7 & 5.6 seconds buffer fill times.

The User Experience reflects the benchmarking results above – the ultimate in smooth scrolling through thousands of albums, near instant album art display goes to the SDXC and DUAL cards…..

Runtime Tests

So as mentioned above we have two playlists, one with 320kbps MP3’s (~6Mb per track) and the other with high bitrate lossless m4a files (~30Mb per track).

The iPod was fully charged, reset and booted up, the playlist was selected and played. This was done for the MP3 and Lossless playlist for each storage medium. I setup a low tech IP camera setup to take a photo of the iPod every minute, which allowed me to time exactly when the iPod switched off (to the nearest minute).


iPod Runtime Comparison

iPod Runtime Comparison

This was always the expected outcome, the mSata drives draw quite large currents during powerup and my iFlash-sata itself has a high performance chipset converting a very high speed SATA bus to the slower iPod PATA bus. The HDD returned a solid performance and sits in the middle ground but having the drawback of its limited capacity. The DUAL returned runtime just under 15% less than the single SDXC card.


I think all the devices performed well and will provide most users with plenty of musical enjoyment between charges, and how far are you from a USB charge port in your day-to-day life?

I should point out mSata drives have varying levels of power consumption, several mSata drives in the 240Gb – 256Gb range will return runtimes approaching that of the HDD. In the 500Gb range again there is varying power consumption levels to contend with.

The single SDXC and DUAL returned excellent runtimes, and I think the DUAL requires a special mention – considering in this test you have double the capacity but only a 15% reduction in runtime, the MP3 playlist on a single SDXC running for  over 49hours, while the DUAL managing an impressive 43hours.

With mSata, you do trade runtime for the best price per GB, which maybe the choice you have to make if you need the highest capacity while keeping costs down. However the iFlash-DUAL does challenge this idea – 2 x 256Gb SDXC can be bought for less than the price of a single 512Gb mSata!!!

What about CF Cards…..

Well Compact Flash card and the iFlash alone will give you about 25% increase in runtimes compared to the SDXC. But, the price per Gb for the 128Gb plus capacities are just too expensive. I have been fortunate in testing a few high capacity CF card engineering samples and I found compatiblity with the iPod to be suspect, several had badly implemented LBA48 addressing which caused restore loop issues on the 7.5g iPod.

So my advice :-

CF upto 64Gb, SDXC from 64Gb to 256Gb, DUAL from 64Gb to 512Gb+ and mSata from 256Gb and up.

I will update this advice as the solid state storage landscape changes.


15 thoughts on “Runtime shootout : Dual SDXC, mSata, SDXC and Original Hard Drive

  1. Pommes

    I just ordered the iflash quad and bought a used iPod 5.5 to use with.
    Can you give me an estimate on run times with the stock battery of 5.5 with iquad?
    Will it be enough or should I try to get the 1900 or 2000 mah?

  2. Anton

    Hello, Tarkan! I have a problem of synchronization (IFLASH with SSD Samsung 850 EVO, 256GB) in my iPod classic. Often there is an file system error after disconnecting the player, and there is a strange file names and folders in my player. I have to restore the player. What could be the problem?

  3. Jamie Hanrahan

    After several failed attempts, I finally settled down to an iPod classic 7th gen with the iFlash adapter + SD card adapter. Yay! I have my 256 GB iPod. (It couldn’t have been a 5th gen because they’re too slow for my car head unit’s iPod interface, even with the iFlash and an SD card.) And I was thinking that if I ever need more than 256 GB, well, there’s the mSATA adapter.

    Now I see that there’s a dual SD adapter! So I can add another 256 GB for just the price of the adapter plus one SD card – the investment in the existing SD card is not lost! Woohoo! (And, no “intermediate” CF adapters are needed any more.)

    The mSATA remained tempting until I looked at the write rates here. So it’s faster, but only about 50% faster. Probably not worth the extra cost.

    Is there any chance that the dual-SDXC adapter could be programmed to use two identically-sized cards in a RAID-like mode that would improve transfer rates? Just dreaming! Well, only half dreaming. 🙂

  4. Max

    Hi Tarkan,

    I have 3 Ipod with iFlash-mSata adapter + mSata cards :
    . Crucial M500 480gb
    . Crucial MX200 500GB
    . Samsung EVO840 1Tb

    All Ipods have a 1900mAH big battery
    I noticed something strange.
    When Ipods are not fully charged, and even when they are fully charged sometimes, if I dock the Ipods on a dock (Pure i-20), there are random pauses or skips when playing tracks while charging the Ipod.
    It seems the Ipod can’t play through dock and charge at the same time without having some problems.

    Did someone ever notice that?
    Thank you,


    1. Support

      @Max – not something that has been reported. Is the i-20 a USB DAC? I know a few people with the 7g 2.0.5/2.0.4 firmware iPods have mentioned a bug when using a large drive / large lossless files & usb dacs – causing glitches on the USB bus.

      Try reducing the library size and see if that makes a difference and playlist size. Is it always on the same type of tracks?

  5. Jonathan

    Hi Tarkan, I’ve had the 128G microSD for about a year, I cant recall whether I ran h2testw on it when I first got it (I usually do). It’s in a rock boxed sansa clip zip at the moment and is working fine for reads and writes, with around 100G of stuff on it. So I’m pretty confident the card itself is fine; I guess I was just unlucky with compatibility. I didn’t check the compat list before purchase, and I already had the SD so I just took a chance. I might buy a 256 or 512 SD from the compat list at some point in the future anyway (getting close to filling the 128!)

  6. Jonathan

    Sorry for off-topic but the relevant post from 2012 has a broken captcha.

    Hi, I’ve recently purchased the iFlash bundle to use in a (originally) 30G iPod 5th generation. I tried to use it with my existing SanDisk SDSDQUA-128G-U46A Mobile Ultra microSDXC UHS-I Class 10. Unfortunately I found the combination very unstable, either with classic firmware, rockbox or just doing IO from the DFU mode. I tried ensuring everything was seated properly but it just wasn’t working, it was very hard to get successful copies onto it and those that did seem to copy successfully would not play back correctly (and doing sha1sum on the files afterwards confirm they haven’t copied over properly). I’ve just swapped it out for a 64G spare I had, and that seems to be working OK. So I guess I’ve just been unlucky with compatibility for the 128G microSD I have.

    1. Tarkan

      @Jonathan – Very odd that card did not work especially failing a CRC check, USB transfer using Rockbox do result in that hence why it is recommended to drop back to the Apple OF. I would run something H2Testw against that 128Gb card on a SDXC card reader just to confirm it is working ok.

  7. mig

    @Wes :Absolutely. The SDXC in a 512GB 1Tb range will be a good choice soon thanks to the dual adapter. And certainly the SDXC ipod batteries last forever.

  8. Wes

    Currently on Amazon (US) the PNY 256GB SDXC are $80 ea which would be $160 for a 512 GB dual card iPod. The cheapest mSata’s on the compatibility list are around $180. For me it is the user experience, how fast I can scroll and find a song. Secondly is run time and lastly how long it takes to sync, which is really only time consuming the first time unless you are continually making huge changes to your song library. It seems then, at least for me, the dual card is a hands down winner, cheapest price, fast response and plenty long enough at 33 or so hours which is better than the original (!) and allows me to fall asleep on the plane and wake up with a still charged iPod vs the mSata. And in the future the 512 GB SDXC cards which are ridiculously expensive now, may be much cheaper in the future and allow an easy upgrade path by replacing either one or both cards.

  9. mig

    Hi, Tarkan!
    I´m getting low battery – sad ipod screens. Cannot reach disk mode nor diagnostic mode. Endless charging process, no progress… you know. I had seen it before but not with a –allegedly– working motherboard.
    These are the batteries I´m using now: I put them with two different iPods I´m building. One of them is finished and works but the battery doesn´t last much. The other one doesn´t work, as told you above.Their respective motherboard are refurbished items bought at the same shop in aliexpress. So I certainly could have two defective boards instead, that´s true. Trying a different battery seems a easy test. My other 5.5 iPods are thick; I had never bought these kind of batteries before.
    I haven´t got the tech background to consider measuring the voltages but it´s good idea and won´t be hard even for me.
    I´m going to test everything, putting this battery in a functional iPod, trying a different drive cable, etc. If someone could give me a clue on good batteries sold at Ebay it would be great , though.

    Thanks for your time and suggests, I will share how It goes. I would like to have this iPod ready for another iFlash. The Dual SDXC adapter looks promising, BTW!

  10. mig

    Excuse me for the off-topic but I need some advice from you people. Preparing a 5.5 iPod for an iFlash mod I´m having a lot of issues with the battery. I have bought two different (and cheap) thin batteries and they don´t last much and give me some sad iPod screens . Which thin battery do you recommend me ?–and links, please–

    I recently put a 2000mAh battery in an iFlash SDXC iPod and it works great but I want a thin back cover for this one.

    Thank you

    1. Tarkan

      @Mig – I don’t have any recommendations for batteries, I just tend to buy them off ebay. I always measure the voltage on them when they arrive, as I have had a few that were around 2.2v on delivery which means the cells are damaged – I don’t accept any batteries below 2.7v as anything below that could indicate cell damage.

      What kind of runtimes are you getting? also are you sure the batteries are the problem and not the iPod motherboard?

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