Topic: what is the maximum capacity or SD card?

[Kees Michielsen]

Great Forum!!!
Did a lot of reading and learned a lot.

Just bought a 998cSi and now I am learning how to use it.
Have read the manual and still have some questions

I want to record a lot of tracks:
How long can you record on  a 8 Gb SD card?
What is the max capacity SD card that the unit can handle?
Can I use 30mb/s SD cards?

Greetings from Holland,

Kees.

[sonar2000]

The maximium capacity is determined with considerations.

Size of the card.
What kind of data being recorded.
Length (amount  of time) of data recorded.
The unit making the recording.

Make some small recordings and then look at the file sizes on the computer.

Remember also to keep recordings small (10 to 20 minutes) so that playback, and if using an external viewer, you dont overload the time to  review.

Chuck

[Humminbird_Greg]

I’ll first answer your question as asked: I believe that the maximum sized SD cards are 4GB (maybe they are only 2GB).  So this would be the maximum sized SD card that your 998c Si unit could use.

However, the maximum sized SDHC cards are 32GB, which will work in your 998c Si unit as well.  The 8GB SDHC Class 10 memory card you have a picture of will work as well.

Yes the 30mb/s memory cards will work in your 998c Si unit.

[RGecy]

The amount of data the HB units record depend on the SI Range and ping rate.  The lower the range the less data per ping, but the amount of pings per second increases.  As the range increases, the data per ping increases, but the pings per second decrease. 

You can set the ping rate in the Snapshot/Record View if you want to keep your recording size smaller.  But you will in essence lose data.  This feature was enabled back when larger size SD cards were not available and very expensive.  In my opinion, this is a feature that can be discarded now that SD cards have increased in size and come down in price.

Another way to keep the file size small is turn off the 83khz sonar. 

Basically, if you want to see how long you will be able to record at a certain range, you could make a test recording.  By timing how long you record and then looking at the total file size, you can divide out how long it would take to fill up a 2,4, or 8gb card.

Here is a post I did a few years back.

Hope that helps.

Robert

The size of the files are related to the Range you record at. So if you are doing alot of recording at less than 100ft SI Range, the files would be smaller than if you were recording at a 200ft SI Range.

Just as an example, there are 1563 bytes per ping, per channel at a 100' Range setting. And it doubles to 3126 bytes per ping, per channel at 200ft. Plus a 67 byte header for each ping as well.

Now, there are at least 3 channels for each ping recorded, sometimes 4. Left and Right SI, and 83khz and 200khz depending if one or both are on.

The number of pings per second also depends on the range. Basically, the shorter the range, the less time it takes for the sound to travel and bounce back, so you will get more pings per second at 100' versus 200'. So, the file size increase from 100' to 200' isn't really linear.

Just a little computer math........

Basically 1563 bytes = 0.00149MB

1 Byte = 8 Bit
1 Kilobyte = 1024 Bytes
1 Megabyte = 1,048,576 Bytes
1 Gigabyte = 1,073,741,824 Bytes


Robert

[Kees Michielsen]

THank you for the reply's!
I tested it today in the simulator-mode, basic settings
I recorded for 10 minutes and the file was about 60 mb.
So, on a 1 Gb SD I can record about 2,5 hr.
snapshot size is about 250 kb

Greetz from Holland 

[sonar2000]

Again...just a caution.....dont make the recording very long.  It will take hours to review.  and it is difficult on playback to move forward and backwards.
for viewers a long or big file can take a lot of time to open..
Chuck

[Humminbird_Greg]

You wouldn't have to worry about how many hours of sonar recordings you could make if you had one of these bad boys!
(Just something I did as a gag  - it is not real)

[sonar2000]

Is that an HB offering or a Greg offering.  Where do we get those monsters..   .... ... ....
Chuck

[RGecy]

Greg,

You have way too much time on your hands! 

[Humminbird_Greg]

That actually as done some time back.  One of the Techs here was crowing about the 2GB Extreme III memory card they got.  You know: my memory card is bigger and faster than your memory card… I had to ‘one up’ them and so went about drawing this up and sent it to them!
I saw this post and thought I would bring that old drawing back out.

[sonar2000]

I agree with Robert....you have too much free time.......I guess that is why we talked for an hour yesterday....hehe....

Ok...now that we have hijacked the original post with our free time babblings........ .... ....

Chuck

[Kees Michielsen]

I think this card is fast enough 

I purchased a 30Mb/s card, works great!!!