Altitude Sickness in computers

I’ve already written about possible altitude health issues on my Snow Leopards photography expedition, but it’s not just me I have to worry about. Computers can also get altitude sickness!

The thinner air means that heatsinks aren’t quite as effective, so care needs to be taken to not overheat the machine. My MacBook Pro (MBP) already has the Monity software installed which lets me keep an eye on the internal temperature gauges.

Hard drives need air

But the biggest risk from altitude is to hard disk drives (HDDs), none of which are rated to run above 3000m altitude. This is because they have tiny magnetic heads flying above spinning disks, and without enough air molecules moving underneath them the odds are high that the heads will scrape the disks.

These “head crashes” are typically fatal to HDDs.

You can try using a hard drive above 3000m, but you do it at your own peril and the higher you go the higher the risk. It’s not just that the HDDs haven’t been tested above 3000m: above that altitude the risk of spontaneous failure of the drive increases (uncomfortably). Some years ago Seagate made special pressurised HDDs for use at altitude, but I think the biggest of these only held 80GB. Solid state disks (SSDs) don’t have this issue.

My MBP already uses an SSD internally, but on expeditions I store my photos on external drives (I store the Lightroom catalog on the internal). A primary drive (an SSD, previously selected for both speed and robustness) plus usually two copies on 2 TB HDDs (which also contain bootable copies of the MBP).

Computer equipment for the Himalayas

For this trip I’ve had to change my equipment slightly. Replacing the HDDs with 2 TB SSDs was an option, but not a cheap one. I’ll be backing up files from Canon 5DsR and 5D Mark IV cameras along with my Olympus TG-4 and although at this point I don’t know how many images I will take, I expect to be bringing back hundreds of gigabytes of images. I will be using the following storage on this trip:

  • MacBook Pro (13″ 2015 model) with 500 GB SSD.
  • Kingston FCR-HS4 USB3 card reader.
  • 960 GB SSD for photo storage (SanDisk Ultra II housed in a Lacie Rugged case with Thunderbolt and USB3/UASP).
  • 1 TB SSD for photo and catalog backups (Samsung 850 EVO housed in a StarTech rugged case with USB3/UASP).
  • 500 GB SSD with bootable clone of laptop plus backup of catalog with previews (Samsung 840 EVO housed in a non-rugged Transcend case with USB3/UASP).
  • 2 TB HDD for extra backup copies (rugged ADATA HD710 with USB3/UASP).
    I won’t be using this while at altitude, but it will be synced when I reach a safe altitude again to give me another backup copy.

My regular procedure will involve downloading the cards to the 960 GB SSD and backing them up to the 1 TB SSD. The 500 GB SSD and the HDD will be packed away most of the time.

The black strips are Velcro “hook” tape, which attaches the drives to the “loop” tape on the lid of my laptop. On some of the SSDs the tape is on the underside in these shots.
All three of those rugged drives (even the HDD) are rated as dust/water/shock-proof (as long as the port covers are closed) which always helps with peace of mind in remote environments.

USB3 SSDs (such as the Samsung T3 drives) are available but at a premium cost compared to using laptop SSD drives housed in USB3 enclosures. Ensuring the enclosures/drives support UASP (USB Attached SCSI Protocol) allows them to work concurrently at high speed, and allows these SSDs to reach speeds of 400+ MB/s. The faster my photos download and my backups can happen, the less stress my laptop will be under.
Note that while many web reviews of the ADATA HD710 say it doesn’t support UASP, when mine is connected to my MacBook Pro I can see that it definitely is using UASP. Possibly there was an internal upgrade by the time my drive was manufactured.

I’ll report after my return from the Himalayas on how these drives performed (along with actual data on how much storage I needed!).



Above the altitude boundary (in Malaysia)

I took this image many years ago with a Canon EOS D30, and I was high enough (3300m) that I didn’t try to use the Microdrive which I usually used for my photos, instead relying on those new-fangled 256 MB solid-state memory cards!

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