4 ms·

The newer microSD cards are quite fast. Not as fast as built-in storage but fast enough for things like photos and videos if you buy a card with the appropriate

by foepys 4y ago

The newer microSD cards are quite fast. Not as fast as built-in storage but fast enough for things like photos and videos if you buy a card with the appropriate speed class. V30 512 GB costs about 40€ including VAT here in Germany. https://en.wikipedia.org/wiki/SD_card#Class https://en.wikipedia.org/wiki/SD_card#Class

hot_gril 4y ago
SD cards are made for cameras etc, and they're good for that. They have sequential RW speeds to match common video formats at 1X speed or burst photo capture. The spec sheets won't tell you how terrible the random write speed is, and even the quoted sequential speeds aren't very good, but that's ok for cameras. I use a modern high-end SD card from SanDisk as semi-permanent storage in my MBP. If I copy anything to that card that's not a single file, it takes forever. Overall it feels worse than using an old HDD. I have to actually think about what I store on it (mostly videos/photos), so I totally see the reason for wanting more internal storage instead of an SD slot.
- Schroedingersat 4y ago
  With a decent filesystem and a ram buffer the better microsd cards still beat an old 5400rpm 128GB HDD's sequential speed when doing random writes of ~500kB files by a fair margin. 150MB/s is nowhere near SSD speed, but it would saturate a SATA I port.
  - yourusername 4y ago
    Considering 100 GB HDD's came out 20+ years ago that's not very suprising. If people are comparing SD cards to HDD's they're probably comparing to HDD's made in the last 10 years.
    - Schroedingersat 4y ago
      OP specifically cited an old hdd in the pre-ssd days. New HDDs are still at best on par with a high end microsd used as internal storage (compare an A2 microsd 'rated' at 2000 but actually getting about 800 iops vs a high end hdd benchmarking at 200-300). Mounting without a buffer on a badly chosen filesystem in what could well be the M1's abysmally slow sd reader isn't a representative test. Hare braned formatting tools will also often offset the filesystem by 512 Bytes (necessitating two writes and two reads for one 4k write) or use blocks that aren't 4kiB
      - hot_gril 4y ago
        FWIW my MacBook Pro is the 2015 Intel version, and my card is HFS+ formatted (Android would use FAT32 or Ext4). I got similar performance with an external USB reader IIRC, but maybe it's time to test again.
        Schroedingersat 4y ago
        Aye, there's your problem. https://web.archive.org/web/20151222043711/https://support.apple.com/en-us/HT204384 https://web.archive.org/web/20151222043711/https://support.a... It's like connecting a QLC SSD through an IDE port and complaining it's slow. It /is/ slow but not that slow.
        hot_gril 4y ago
        Is the issue the 480mbit/s USB limit? That's still a lot more than what I was getting with random writes.
        Schroedingersat 4y ago
        USB 2 has very poor latency for this use case and the sd connector lacks the pins for newer sd cards. A usb 3 UHS III reader would be able to talk to the card at full speed, then it's a matter of convincing the OS to trim it and buffer as if it's an internal hdd. Kinda expensive and pointless to go to that effort to get 2x hdd performance when there are NVME enclosures for cheaper SSDs that have 100x the IOPs though.
  - hot_gril 4y ago
    I'm not sure about that test cause there are too many variables, but in the typical real-world usage of like cloning a git code repo onto my SD card or opening a zip file, it was always painfully slow. I wasn't even benchmarking, I was just trying to get stuff done and not wanting to wait on it. In fact I moved the files to an HDD to do it one time.
- kuschku 4y ago
  > even the quoted sequential speeds aren't very good, but that's ok for cameras The SD cards usually used for mirrorless cameras, when recording video, have to write at 600 Mb/s. That should be plenty for most apps in phones. (e.g. ProRes 422 at 4K 10-bit or XAVC-I 4:2:2 at 4K 10-bit)
  - hot_gril 4y ago
    That's only sequential write speed. Of course the camera features on a phone will have no problem using an SD card, but other stuff dealing with more random writes to things like SQLite stores (common for phone apps) or directory trees might. Like I said, I've only used an SD card on my Mac, and it was a bad experience, so I'm guessing a bit about phone usage. 90MB/s is slower than most HDDs, btw.

by foepys 4y ago

hot_gril 4y ago

SD cards are made for cameras etc, and they're good for that. They have sequential RW speeds to match common video formats at 1X speed or burst photo capture. The spec sheets won't tell you how terrible the random write speed is, and even the quoted sequential speeds aren't very good, but that's ok for cameras. I use a modern high-end SD card from SanDisk as semi-permanent storage in my MBP. If I copy anything to that card that's not a single file, it takes forever. Overall it feels worse than using an old HDD. I have to actually think about what I store on it (mostly videos/photos), so I totally see the reason for wanting more internal storage instead of an SD slot.

Schroedingersat 4y ago
With a decent filesystem and a ram buffer the better microsd cards still beat an old 5400rpm 128GB HDD's sequential speed when doing random writes of ~500kB files by a fair margin. 150MB/s is nowhere near SSD speed, but it would saturate a SATA I port.
- yourusername 4y ago
  Considering 100 GB HDD's came out 20+ years ago that's not very suprising. If people are comparing SD cards to HDD's they're probably comparing to HDD's made in the last 10 years.
  - Schroedingersat 4y ago
    OP specifically cited an old hdd in the pre-ssd days. New HDDs are still at best on par with a high end microsd used as internal storage (compare an A2 microsd 'rated' at 2000 but actually getting about 800 iops vs a high end hdd benchmarking at 200-300). Mounting without a buffer on a badly chosen filesystem in what could well be the M1's abysmally slow sd reader isn't a representative test. Hare braned formatting tools will also often offset the filesystem by 512 Bytes (necessitating two writes and two reads for one 4k write) or use blocks that aren't 4kiB
    - hot_gril 4y ago
      FWIW my MacBook Pro is the 2015 Intel version, and my card is HFS+ formatted (Android would use FAT32 or Ext4). I got similar performance with an external USB reader IIRC, but maybe it's time to test again.
      - Schroedingersat 4y ago
        Aye, there's your problem. https://web.archive.org/web/20151222043711/https://support.apple.com/en-us/HT204384 https://web.archive.org/web/20151222043711/https://support.a... It's like connecting a QLC SSD through an IDE port and complaining it's slow. It /is/ slow but not that slow.
        hot_gril 4y ago
        Is the issue the 480mbit/s USB limit? That's still a lot more than what I was getting with random writes.
        Schroedingersat 4y ago
        USB 2 has very poor latency for this use case and the sd connector lacks the pins for newer sd cards. A usb 3 UHS III reader would be able to talk to the card at full speed, then it's a matter of convincing the OS to trim it and buffer as if it's an internal hdd. Kinda expensive and pointless to go to that effort to get 2x hdd performance when there are NVME enclosures for cheaper SSDs that have 100x the IOPs though.
- hot_gril 4y ago
  I'm not sure about that test cause there are too many variables, but in the typical real-world usage of like cloning a git code repo onto my SD card or opening a zip file, it was always painfully slow. I wasn't even benchmarking, I was just trying to get stuff done and not wanting to wait on it. In fact I moved the files to an HDD to do it one time.
kuschku 4y ago
> even the quoted sequential speeds aren't very good, but that's ok for cameras The SD cards usually used for mirrorless cameras, when recording video, have to write at 600 Mb/s. That should be plenty for most apps in phones. (e.g. ProRes 422 at 4K 10-bit or XAVC-I 4:2:2 at 4K 10-bit)
- hot_gril 4y ago
  That's only sequential write speed. Of course the camera features on a phone will have no problem using an SD card, but other stuff dealing with more random writes to things like SQLite stores (common for phone apps) or directory trees might. Like I said, I've only used an SD card on my Mac, and it was a bad experience, so I'm guessing a bit about phone usage. 90MB/s is slower than most HDDs, btw.