Sd card question

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ofd8001

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I love SD cards for scanners. It is so much easier to update programming for mobile mounted scanners. No more struggling to get a laptop computer and turn the vehicle on.

The SD card cost is modest and keeps going down
 

Ubbe

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Yes why are we using them in scanners? Extra money to spend plus ther cheap on Amazon.
There's an extremly low strain on a SD card when used in a scanner. You can buy the cheapest ones. SD cards in a scanner doesn't wear out from use. When you read the user review on Amazon from both normal and endurance types they seem to fail randomly and there are several that write that their endurance ones failed more often but are probably just a coincident. So it probably doesn't matter which ones you buy. If you are unlucky it will fail regardless if it is a standard one or extreme or high endurance. The important thing are to have one backup on you with a copy of the current programming that are in the scanner.

/Ubbe
 

jonwienke

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@Ubbe everything you wrote is wrong. The scanner writes to the card with every transmission unless you disable replay and recording, and given the fact that flash has a limited number of writes before it fails, cheap cards will fail fairly often. There are dozens of threads and hundreds of posts in the forums here documenting that fact if you bother to look. Uniden switched to high endurance cards because there were so many complaints about card failures, so it's pretty obvious that there is value in using high endurance cards.

@ofd8001 extreme cards are optimized for data transfer speed. Extreme cards came out before high endurance flash, so I'm pretty sure they aren't. Get a card that specifies it's the high endurance type.
 

ofd8001

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I was kind of going on Upman's post of 4 years ago:

The benefit of MLC, and what makes it worth us changing even though it will be at a lower (but still the advertised) capacity, is that MLC NAND memory has a tremendously longer life. It is recommended for use in dashcams, security video cams, and other devices that do intense data writing. They advertise up to 12,000 hours of continuous video writing before failure (in 64GB cards).

So, when you go to replace your card, we are now highly recommending you get an MLC type card. They are typically advertised as "industrial" or "high endurance."


It seems the photography side of things (which I also keep up with) talks a lot about the Extreme cards.
 

Ubbe

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The scanner writes to the card with every transmission unless you disable replay and recording
I don't think people believe that enabling recording to SD card in the scanner does not include actually writing to the card. I speak about a non replay and record scanning mode, that probably are the most used mode. Even if the replay are always on it would be impossible to wear out a SD card from the shear number of writes to one sector even in a small 4GB SD card.

SD cards are specified to withstand hundreds of hours of recording videos. Those are 10Mb per second and higher. Unidens scanner recordings are 128Kb per second, a hundred times less and have a hundred times longer life of writings to the card. The SD controller jumps to the next sector in the card with each write, even if you erease the previous sector. It will go to the end of the SD cards memory and only then it starts to use that first sector again. If you have the whole database and favorites on the card you couldn't fill up a 4GB size with continous recordings even in a full day and that would be one write cycle to each sector in the SD card, and it can take 100,000 writes to one sector until it wears out. That's 200 years of continuous 24 hour audio recordings. So it is impossible for a scanner to wear out any SD cards secors from too many write cycles. It is other factors that breaks a card and are random failures that hits any kind of standard, endurance or extreme cards.

"Taken from the "SanDisk SD Card Product Manual":
"SanDisk SD cards have an endurance specification for each sector of 100,000 writes typical (reading a logical sector is unlimited).

Therefore, extremely heavy use of the card in cellular phones, personal communicators, pagers and voice recorders will use only a fraction of the total endurance over the device’s lifetime. For instance—it would take over 10 years to wear out an area on an SD Card based on a file of any size (from 512 bytes to maximum capacity) being rewritten 3 times per hour, 8 hours a day, 365 days per year."

/Ubbe
 

jonwienke

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Well, since Replay is enabled by default, most people have it running.

And tbe spec you quoted is for high endurance cards. Standard cards are rated for ~5000 writes to a sector before failure.

The other relevant point is that individual sectors follow a bell curve distribution for write failures, and it's the outliers on the low end of the curve that cause problems. So if the average sector failure point is 5K or 100K writes, you're going to have some card issues well before reaching that. Which is why Uniden switched to high endurance cards about a year before UPMan died.
 

Ubbe

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And tbe spec you quoted is for high endurance cards. Standard cards are rated for ~5000 writes to a sector before failure.
OK, so it is only 10 years of continuous 24h recordings as the guaranteed life time. Switch to a standard type 32GB size and it's 80 years. When the card controller detects a cell that doesn't verify a write succesfully it will mark that cell as bad and not use it again.

/Ubbe
 

jonwienke

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Again, in the real world, Uniden had a big problem with card failures, and there are dozens of threads in the archives devoted to people complaining about problems with their scanner due to card issues.

You've been a member here since 2006, long enough to remember that being a hot topic, and UPMan eventually posting that Uniden had switched to high endurance cards. And after the switch, complaints about card failures dropped way off.

You're giving bad advice that contradicts real-world experience, and you should know better.
 

Ubbe

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I'm only stating the facts, what info SD card manufactures give and what users that stress SD cards much more like photographers and surveillance camera users, dash cams and whatnot have to say. I have my HP-1 on constant replay daily since 10 years with the original Uniden card. Uniden must have gotten bad batches, like they got bad batches of LED display backlight and clock battery backup components.

I started using SD cards when they begun being affordable, 20 years ago? and have never had one SD card go bad. People I talk to have also never experianced a bad card. It must be a very rare occasion outside of the Uniden community, or it would be a lot of voices being raised of lost photage and files going missing. The only bad card i have where the one that Whistler supplied in the TRX-2, it was dead from the start and cannot be formatted and are not even recognised in a computer.

/Ubbe
 

jonwienke

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Card failure is a recurring topic among digital photographers; losing a few hundred wedding shots when a card fails can make grown men cry. It's absolutely not a Uniden-only thing.
 

pb_lonny

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Card failure is a recurring topic among digital photographers; losing a few hundred wedding shots when a card fails can make grown men cry. It's absolutely not a Uniden-only thing.

Correct, when I was serious about photography, I had two cards die, neither had taken more than 10,000 photos...
 

jonwienke

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Some pro cameras have two card slots, and allow files to be written to both simultaneously for that reason.
 

ofd8001

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Some pro cameras have two card slots, and allow files to be written to both simultaneously for that reason.

And most us folks who are serious/professional photographers would not consider a camera that does not have dual slots. The real high end use XQD cards because they have a better life span, with the SD card being a backup.
 

pb_lonny

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Some pro cameras have two card slots, and allow files to be written to both simultaneously for that reason.

Thankfully in both cases they failed when I first went to use them after downloading photos off them. This was on different brands of cameras, about 6 months apart.
 

Ubbe

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If it is the memory cells that go bad from lots of writes to them, then the SD controller marks them as bad in the same way a harddrive does and in worst case you loose one file. What happens in most cases to non-Uniden users are that the whole SD card go bad and cannot be used and that are not from wear and tear from number of writes to the memory cells, that are different for different standard, extreme and endurance types, it's the SD's electronic logic controller that stops working and that's of the same (low) quality in those SD cards and are just dependent of luck if you get a controller that will hold up for the whole life span of the cards max number of write cycles.

Uniden have a history of bad quality in their connectors from BC780's display ribbon connector to todays rotary encoders and what I suspect happens to most Uniden users are that the SD card sits in the scanner and are not moved for a long time and starts to get a bad connection between SD card and the scanners connector. Then the user gets a new SD card and at the process of switching SD card the surface of the connector are freshen up and scanner works again. But it probably would work anyhow if the original SD card where removed and reinsterted again. Most of those suspected problematic Uniden SD cards probably works just fine when tested with a computer SD card interface and can be used without any problem in other devices.

/Ubbe
 

jonwienke

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Exactly how does Uniden's QC cause card failures in a Canon or Nikon camera?

And failed scanner cards show do show errors when put in computer, so you're wrong about that, too. You have zero basis for your assertions if you've never personally had a card fail.

The bottom line is that contrary to all your bluster, card quality does matter, cheaper cards can and do fail with normal use in a scanner, and upgrading to high endurance cards offers a significant, measurable improvement in card reliability. Claiming otherwise ignores plenty of real-world evidence.
 

ofd8001

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Uniden have a history of bad quality in their connectors from BC780's display ribbon connector to todays rotary encoders and what I suspect happens to most Uniden users are that the SD card sits in the scanner and are not moved for a long time and starts to get a bad connection between SD card and the scanners connector. Then the user gets a new SD card and at the process of switching SD card the surface of the connector are freshen up and scanner works again. But it probably would work anyhow if the original SD card where removed and reinsterted again. Most of those suspected problematic Uniden SD cards probably works just fine when tested with a computer SD card interface and can be used without any problem in other devices.

I remember seeing at least a few posts where someone has a problem SD card and will try to re-format it in a card reader to no avail. Also you'd think that a good number of folks experiencing SD card failures would have sense enough to clean the contacts before saying there is a problem.

And I go back to Upman's post of 4 years ago Replacement SD Cards

"All devices will eventually wear out an SD card (if it does any writing at all). I typically have to replace my dashcam's 2 cards every 3 months or so. It is just the nature of the SD technology."
 
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