Regular formatting of SD card?

Have a couple of Wyze cams working fine, doing continuous recording to SD card with no real issues

Have now just bought a Dash Cam, and one of the menu options was “Format warning”
I queried this with them and was told Yes, you should regularly format card, say once a month, and this option triggers the user to do that.
I hadn’t really considered that an SD might need that regular maintenance

I don’t recall Wyze stating that this might be a requirement, although Googling the subject does indicate its something which is beneficial, speed and capacity wise , after all they are based on the FAT format and we all used used to defrag our PCs quite regularly .

What are the groups thoughts on the subject ?

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I am not an Engineer, but I have friends that are :grinning::grinning: The format/do not format debate is full of misinformation. This is how it was explained to me.

First of all SD cards do not physically suffer from fragmentation like magnetic storage media does. The access time for any gate on the card is identical, there are no moving parts so no penalty for non contiguous storage or access.

Second “Erasing vs Formatting”, Erasing files from a card like on a magnetic drive simply marks the gates used by the file as available again. Formatting or as us old timers call it Low Level Formatting physically resets each gate to its default state and tests the gate for responsiveness and ability to accept and hold a state. This is why its slower.

For cameras its called “initialize” the card. And what exactly that means varies from camera to camera vendor and even model. For some it means erase the card, for others it means format the card.

My personal practice is to “format” each card in the device it is going to be used in when its first installed and then let the device manage the card. If a card develops errors (They all eventually will) I replace the card immediately. They are relatively inexpensive and usually when errors appear its a short time before they proliferate.

Some folks format cards in a computer first then move them to the device. Its personal preference I have never personally needed to do that. In a continuous recording scenario like I use in my Wyze cameras I have typically gone 1 to 2 years before I see problems develop.

So I don’t have a clear cut answer for you. I spoke with an Engineer at a card manufacturer at length once (We had dinner together at a trade show) he said there was no benefit to periodically formatting a card from an electrical engineering viewpoint.

So as they say YMMV but usually I keep a few spares around and otherwise let nature and electricity take its course.

The problem with using a computer to format an SD card that is going to used in another device is that there are 37 different formats (many proprietary) and unless the device specifically states the format used you may be doing more harm than good formatting via a computer.

Also, never never insert or remove an SD from a powered device. That corrupts the SD card and if it doesn’t fail immediately it will soon and also be unreliable for any time that it does operate.

Finally, keep your fingers off of the contacts.

And I am a retired Engineer (Nuclear, Electrical, Electronic, Mechanical, Plant). Been there. Done that.


I think we should start a new thread on SD cards. What the classes mean, what the UHS class means what the various letters and symbols mean as well as good/safe handling practices for using SD cards, getting video off the card (event or continuous) basically your one stop shop for SD cards with a focus on using them in Wyze products?


that would also quickly grow crowded with ( this worked for me though) posts even though whatever it is might be proven to be false numerous times over.

for example. lol i humbly submit this post. ( and for some reason despite even the company saying not to do it, low level sandisk cards are still used in these cameras and get the “it worked for me” treatment)

I think as long as you buy the right class, and stick to reputable sellers to avoid counterfeits brand does not matter. We have all seen posts that say XYZ brand is trash based on ABC, followed by another post claiming the same type of card is fantastic! And I can’t tell you how many times I have read where someone said a particular brand/type of card ‘never’ fails only to later stumble onto a thread that says someone had terrible experiences with that card and lost their Phd (Piled Higher and Deeper) paper and now lives in a cardboard box.

So I think if we stick to non brand specific discussions we would be fine.

I think Bam posted it first, maybe somebody else.
You get a new card, TEST IT
h2testw_1.4 or similar
Don’t touch the contacts
Keep it in the cam.
I’ve had several cards out of about 20 that failed testing.
The 32GB limit is a pain, but so wasn’t the 55mph speed limit and the 640K memory limit.