Wednesday, January 15, 2020

DIY - Selectng a USB Drive for Sentry Mode & Dashcam

I have been testing a few different combinations of recording device options and I can share some results.

I started with a Transcend 256GB JetDrive that I used to use on my Mac with a Trancend USB 3.0 Card reader. I had read on forums that GPT was better than MBR in terms of partition choice. (Note that most SSD cards/ USB drives come formatted as MBR with FAT32 or exFAT if  greater than 32GB).
Trying to reuse some hardware laying around. GPT was too slow. Adapter ran too hot

Unfortunately, this combo above only worked for a few minutes before I got the dreaded too slow error. GPT I suspected was the culprit.

There are a number of tools that I use verify this are a combination off dd command on a linux box or Crystal DiskMark for Windows. For formatting, I use Gparted on a Linux box to format large devices with FAT32.  I used diskpart (via command line not powershell) to convert between MBR and GPT. Unfortunately, nothing on windows compares. If you want to use a hypervisor, I recommend VMware Workstation (trial) as that is the only one I have found (compared with VirtualBox and HyperV) which allows direct USB access and therefor proper formatting.

So I check this combo with a simple dd test using sequential large blocks and it ran 1.3MB/s. I converted it to MBR and reformatted FAT32. DD ran about 11MB/s writes and 78 MB/s read. It gave no errors for TeslaCam with 1 day of driving around, but ran too hot. Too hot for my liking and I did't like how it stuck out of the USB port, could be prone to accidental breakage when using the storage space. So it was time to investigate some options and run some test and found that I am not a fan of USB to SD card adapters.

Not being a big fan of transcend as they have f&%$-ed me over on warranty before (sent me a microscope pic of the gold on the microSD card contacts being worn from insertion/removal from their own SD card adapter and rejected warranty - WTF!)

Anyways, I ordered both a SanDisk UltraFit 128GB USB Drive and a SanDisk High Endurance 128GB microSDXC. What I found in my tests first was that they both come as MBR.
One of the devices that I tried and eventually settled on.

The UltraFit gave 116MB/s read and 56MB/s write (specs: operating range 0C/32F to 35C/95F and 5 year warranty)

The HighEndurance gave 85MB/s read and 74 MB/s write (specs: operating range -13F/-12C to 85C/185ºF and 10,000 Hrs of recording durability, but only a 2 year warranty).

With regards to warranty, SanDisk states the UltraFit if used for video recording devices voids the warranty. Having worked 12 years for a storage vendor. I feel that based on the plummeting cost of storage devices these days most manufacturers are going to make warranty claims difficult, it costs them too much. Professional photographers that run through cards like toilet paper don't even care about the warranty, basically cost of doing business. That is why I took the approach of a $18 128GB USB drive which I will return if it breaks in 90 days or throw away if/when it breaks. Think of it as a cost of TeslaCam and Sentry Mode (well other the the kWh burned :-))

Since both of these meet the 10 MB/s or minimum threshold for TeslaCam with v9, which maybe higher with V10 since it records rear cam as well, so to be safe let's say 15MB/s as a minimum. Read speed really doesn't matter much for this use case. Both have been worked well swapping them out a few days each.

Here was the double edge sword: I like the fit of the Ultrafit USB drive, it sits flush in the usb port and is completely unnoticeable in the dark console. It runs barely luke warm at best.
Such a nice inconspicuous fit.
The high endurance one needs to go into a adapter and after a number of different small form factor and even larger USB adapters, they all seem to run hella hot (too hot to touch sometimes) while being used for TeslaCam. So while I am glad that the SD card can handle 185 F, the adapters seem to be the weak link (many bad reviews and pictures on amazon where the plastic on the outside of the SD card melts while inside the adapter). I also did not want to use a SSD drive or NVMe, albeit having a few laying around, as those are even more temperature sensitive and require more adapter and wire and more power.

So have settled on the SanDisk UltraFit for now with the hope that SanDisk honors the 5 yr warranty if/when it crashes, as they have done in the past with many of their other SD cards in Camera. Unlike cheapo cards, my experience with SanDisk is that their devices will go into a Read-Only mode before crapping out and allow you to copy off your files, just not write new ones or reformat. Then spend another $15 and get another.

I use the SanDisk high endurance 32 GB in all my other cars where I have after market dashcams, but in these I do not have a little red icon as in the Tesla telling me recording is working and they run very cold as they accept microSD cards directly instead of via a USB adapter.

I left Sentry mode on at the airport this weekend for 2-day and it worked like a champ. Even though the ramp was empty when I left and came back to being parked besides an F150 on one side and dodge RAM on the other. I was able to see and appreciate how both truck drivers took time not to let their doors ding my Tesla or luggage scratch the paint.

One other mention-able thing is that the first time you take the TeslaCam card out and put into a Windows 10 PC, it will say there is an error and windows can fix it. Not sure what Windows is doing, but if you accept the fix, it is messing with the card making it flaky with TeslaCam after the fact. It seems to work better if you tell Windows not to fix it, as you can still see the video, whcih seems to play better on VLC than Windows player.

Happy recording and may nothing happen to your Tesla Model 3 but if it does, hopefully the culprit is caught.