Micro SD card type


#1

Folks, curiosity, with a Pi just running PiAware does it matter if a class 4 microSD card is used?

Appreciate not a great difference in price but the class 10 cards seem to be higher capacity which is not really needed for PiAware.

Geffers


#2

I don’t think it does, if used just for Piaware. Add other things, like additional feeders or graphs, and there may be a problem.

That said, I don’t see cards smaller than 16GB these days. 8GB should be the minimum, even when it’s said that 4 GB is enough. Coincidence or not, when I was using 4GB, I had to re-image the cards every few weeks.

I have not been lucky with the so called ultra high capacity cards, they seem to fail very quickly. I buy the plain class 10 only, but it’s also getting harder to find.


#3

PiAware is setup to minimize writing to the SD card. Default is to write log files to the SD card and any software updates. Any other programs that require writing to the SD card will wear them out faster.

The Class of SD card is the speed of the write. This is very important if you are capturing video and saving the data locally. This is not important for PiAware since the plane data is not stored locally on the SD card.

Older SD cards had a class rating from 1 to 10. Newer SD cards have a U rating from 1 to 3. U rated cards are faster than the class rated cards. A faster SD card will speed up piaware software updates only. It will not improve the performance of your site.

The Class and U rating of a SD card will not tell you how reliable a card is. The ratings are only for write speeds. SanDisk and Samsung are known to make very reliable SD cards.


#4

Thank you.

As said, not really a cost issue so was just curious as class 4s tend to be available in smaller sizes.

Geffers


#5

Thanks Dxista, just saw a decent brand 16GB class 4. Most of the class 10s seem to be 32GB+

Geffers


#6

My issues were with the SanDisk Ultra type. Other online reviews seem to show that they are hit and miss.

The next card will be a Samsung. Not as many reviews, but the reviews are generally better.

The most important thing of all is where you buy them, any brand. Counterfeit cards abound, even on respectable online sites. Buyer beware.


#7

I have 5 microSD Cards, 8GB, Class 10 - Three are ADATA, and two are Kingston. These are in use for about 3 years.

To upgrade, or to experiment with software, or to solve tough software bugs, I prefer fresh install (format microSD card & write fresh Raspbian/Piaware image). As a result all of these microSD Cards have undergone a very large number of write cycles. Even after this hard life, these all are still healthy and happy :slight_smile:


#8

Is there any way to get the app to write the flight history to another source, ie thumb drive, NAS etc?


#9

Agree, I too prefer the fresh install though don’t have cause to do so.

Question only arose due to FlightAware being the only software running therefore space not an issue. Storage is cheap nowadays and it was more of an enquiry question rather than a necessity.

Geffers


#10

class 10 or 4 performansta effect


#11

If I understand you correctly re flight history the flight data can be downloaded from FlightAware main site so can be saved on any computer.

Geffers


#12

In my experience the Class 10 cards are more reliable than the Class 4 ones. U class cards are all very good.
And, if you think how they are selected, it makes sense.
The memory is “made” all at once on big silicon wafers. All are the same, there are no dedicated wafers for Class 10 or Class 4. But, because the focusing of the mask is better on center and slightly weaker on edges of that wafer, inherently the chips cut from the middle of the wafer have better chances to perform better and last longer (domains are better defined).
The cutting process selects the center for higher speed chips and the edges for lower speed clock. In this way they minimize the waste.
This happens with all the chips - CPU’s GPU’s. They also have programmable “fuses” on chips to identify the type of the chip as lower speed, and this is done automatically, without actually testing the speed (would take too much time for lower class, too costly).


#13

This is very interesting information- makes sense.