Originally Posted by Skitz1967
Ok after further testing I am sad to reply that all my sdcard tests over time have proven to be unreliable.
Tested with a high quality micro sdcard with 2 different readers as well as just an old 8 gb dedicated sandisk usb and was not happy with the results over time of any of them.
Really the only valid options are:
2.5 laptop hard drive in usb 3.0 enclosure (no need for external power)
Powered Hard Drive
Yes, further testing is no day at the beach...I thought I had found a USB flash drive that worked on an old iView, then it didn't when I really needed it...
But lately I've been testing a USB flash drive that has NEVER failed to work perfectly on all channels in all recording modes. It is the SanDisk Ultra USB 3.0 Flash Drive which can be procured for $12.99 for 32GB and $20.99 for 64GB at I think all Target brick and mortar stores (SanDisk also makes larger versions all the way up to 256GB for about $70 on Amazon). It has also been reported that a "PNY Turbo Attache" flash drive works well too, although I don't own that one.
As near as I can tell, the difference between functional (for mStar recording) drives and all non-functional drives has something to do with the controller, not necessarily the absolute write speed of the flash media. You absolutely need a write speed for large sequential files of around 25-30Mbps, but you also need read/write buffers or something of sufficient size in the controller (this would apply to SSD and SD card controllers as well).
It appears that one way to determine if a flash drive MIGHT work is the width of the drive, since a controller that works can only be miniaturized so much. So super-slim and "fit" flash drives are right out. But the only way to KNOW FOR SURE is if somebody has rigorously tested it on a mStar box (and I mean RIGOROUSLY, I can actually test on 1080i channels here that run at an almost 2Mbps higher data rate that even the highest 1080i channel you're likely to encounter).
One implementation note: you might want to use the NTFS format option on the mStar box to format the drive. This will set the read segment size to 4kB, rather than the 64kB (or greater) size usually recommended in these forums. I ran some tests on different segment sizes, and it seemed to make some difference, particularly for "time-shift" or "chase play" recording on other drives.
Other note: I am right now playing back a scheduled recording 720p DD5.1, it is perfect. I am about to schedule another recording for this afternoon, 1080i DD5.1, but with an abnormally high data rate, you'll be the first to know if it has any problems.