As there have been complaints regarding USB, I just did a quick test with several USB sticks – all of them fairly old, some even right from the stone age. I have often seen the advice for various instruments from various manufacturers to use flash drives up to 4GB with FAT file system only, so I was curious how the Siglent SDS1104X-E would deal with the bigger ones. I would have liked to try even higher than 32GB, but I can’t find anything bigger/better here in my lab, so someone else would have to chime in for that.
NoName 512MB FAT16 USB2
Platinum 2GB FAT16 USB2
Transcend LF V30/ 4GB FAT32 USB2
SanDisk cruzer contour 8GB FAT32 USB2 (with additional ~7MB CDFS partition)
SanDisk cruzer edge 16GB FAT32 USB2
Transcend 32GB FAT32 USB3
All these were recognized by the scope without problems and the directory could be displayed correctly.
I happen to have two of the NoName 512MB and these are regularly in use with the Siglent scopes, have always been absolutely reliable and I never felt they were slow either.
I also tested the remaining ones by storing a screenshot on each of them. To my surprise even the oddball SanDisk cruzer contour worked without problems just like the others.
For the screenshot tests I removed the sticks immediately after the “saved to file …” message of the scope had disappeared. No loss of data, no problems. There was no noticeable speed difference, but then again, what to expect when a screenshot just takes a fraction of a second anyway?
This got me curious to make a quick performance test: writing binary raw data for a 4x7Mpts record. This results in a 26.74MB binary file. Since all these sticks have seen heavy use before and were not even freshly formatted (which is unlikely to make a difference anyway), write speed could be expected to be as slow as it gets. For a fair comparison, I took three measurements for each device and only used the fastest result. After all it’s more about the performance of the scope and not the ancient sticks.
USB Stick time (s) Speed (MB/s)
NoName 512MB 3.23 8.20
Platinum 2GB 8.35 3.20
Transcend LF V30/4GB 6.11 4.38
SanDisk cruzer contour 8GB 2.99 8.94
SanDisk cruzer edge 16GB 2.85 9.38
Transcend 32GB 2.66 10.05
And the winner is … pretty much all except for the old Transcend LF V30 and particularly the slow Platinum (in actual fact another noname), which takes the red lantern, but all others are pretty close.
It is interesting to see that age and size don’t make much of a difference and even after that test I do not see any reason to replace my old 512MB FAT16 nonames.