Interesting solution for a 2.5" SATA HDD formfactor. I wonder how much this PhotoFast adapter will cost in the US?
I can buy 16GB SDHC Class 6 cards for just over 50 bucks each, yielding 16GB x 6 = 96GB. SanDisk's new 32GB SDHC Class 4 card currently costs $130 (not sure about Panasonic's 32GB Class 6 and Toshiba's 32GB cards), but should come down over time, yielding 32GB x 6 - 192GB. In contrast, there are already 500GB 2.5" HDDs, and Toshiba will release a 160GB 1.8" HDD...
Unfortunately the PhotoFast specs are displayed as a Flash image so Google Translate doesn't work. But I see snippets such as:
- RAID 0
- 130MB ... 85MB
- MLC ... SDHC ... 60MB
I have two concerns with using this as a SATA boot drive. First, I'm not sure how reliable this 6-card RAID 0 solution will be as a primary drive. Not withstanding the reliability of the controller/adapter itself (?), I'm not sure that SD cards are tuned the way SSD drives are (regarding wear leveling, for example). So striping 6 of these cards together could be risky?
Second, SDHC speed ratings only go to Class 6 (meaning a minimum sustained speed of 6MB/sec). Cards often advertise a higher (maximum) speed such as 20MB/sec, but I would like to find an SDHC card with a guaranteed sustained speed higher than Class 6. Heck I don't understand why flash cards even have different minimum/maximum speeds, since they don't have a moving platter to contend with different inner/outer track speeds. I mean, that's why flash storage has negligible access latency in the first place (don't need to seek on a moving platter), right?
Then again, I suppose RAID 0 could substantially increase the (sequential) sustained read/write above that of a single SDHC card?
Anyways, I would prefer to use something like this as an external drive. I know I can insert this PhotoFast SATA product inside a 2.5" USB drive casing, but that seems unnecessarily convoluted... I'd like a small (around 1.8" formfactor size) USB (or USB/eSATA combo) enclosure that also takes 4 to 6 SDHC or microSDHC cards concatenated in some way. That's because I do appreciate the flash benefits: low power (single USB port sufficient), vibration/shock proof, silent, negligible access latency, etc.
For microSDHC, I can buy 8GB Class 4 cards for 40-50 bucks. SanDisk's new 8GB Class 6 card started out at $100 but is now already down to $60-70. SanDisk's 16GB Class 4 card was supposed to be out by June, but it'll probably cost a lot.