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Why Do Flash Drives Cost So Much?
Alvin Pettit asks: "I wanted to get a Flash drive for my PC for the following reasons:
it is quiet, I can save electricity and I don't have to worry about moving parts. When I looked for these drives I found them to be rather expensive, much more so than the smaller devices such as CompactFlash! Why do Flash drives cost so much more than CompactFlash devices?"
"I looked up IDE flash drives compared to compact flash and this is what I found:
- On pricegrabber:
SanDisk Part# SD25B880402 880MB IDE 2.5 FLASHDRIVE is $1148.00
This comes out to about $1.30 per meg - Where a compact flash is
SanDisk Part# SDCFB1000768 1 GB COMPACTFLASH CARD is $589.00
This comes out to about $.60 per meg - Even Ultra Compact flash is cheaper:
SanDisk Part# SDCFH512784 512MB COMPACT FLASH ULTRA is $268.00
This comes out to about $.52 per meg
a 1 gig flash card is limited by your USB speeds
a 1 gig flash drive is limited by your system bus speeds
the drives are MUCH faster
Buttsex.
...it's probably for the same reason that Solid State memory costs more than regular DRAM.
Only in slashdot are posts of solidarity modded at -1 Redundant, while posts of antagonism are modded as -1 Flamebait.
1) Demand is much lower
2) Parts count is much higher
You can get a card reader for a desktop machine ($15-$80, depending on what you want) and just use compact flash cards. It just takes a lot of effort to boot from one. It is possible, though.
From what I've seen , and what the guys at wearables it is indeed possible to construct a low power pc that boots off a PCMCIA (adapted CF) card.
Although their end goals are not identical as yours, their immediate needs (low power) are the same.
Why does nobody make one with a write-protect switch???
They would be perfect for storing Tripwire databases, read-only boot partitions, etc. I've looked all over, though, and as far as I can tell, all of them are permanently read/write.
Sensei Google says: DRAM is cheaper.
I beleive that Compact Flash cards are IDE compatable, all you need is to wire them up correctly.
This google search should get some results
They're not the same thing, or at least they shouldn't be. Flash memory is *really* slow, fast random access, but spectacularly slow read/write. And it wears out. A good quality flash drive should be a stack of DRAM, a battery, and some way of backing up the DRAM when the power gets yanked (and vice versa). As you can imagine, this costs a bit and since it has low demand, it is also expensive.
Dave
I write a blog now, you should be afraid.
Why do flash drives cost so much more? Most likely because they aren't easily found. They're not used much, and I'd assume that most of them have very fast access times (which is what you're paying the most for. Faster chips can be expensive as hell, but I bet there is nothing like being able to saturate your IDE channel with just one drive that you can't even hear). Of course this doesn't make a ton of sense, because to put a gig in a little CF card, the chips have to be incredibly small and dense. To put a gig of memory into something the size of a hard drive wouldn't need very dense or small chips (relitivly) and they could use more chips of lower densities so they should be able to get a decent discount.
My last comment for you is this: the ATA specification is very well documented, and RAM is cheap. If people can interface PIC chips, HC11s, FPGAs, and other things to IDE, they someone could too. I wouldn't be terribly suprised if there was a project out there somewhere (shouldn't be TOO hard to do anyway) to basically turn a bunch of RAM into an IDE drive. Then all you'd need is some sort of battery to keep it going when the PC is off. Plus it'd be easily upgradeable.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
Why do you want them more?
but the real thing you should be thinking about are your writes. unless you're mounting the drive read-only, you WILL ruin the flash. each sector only supports a finite amount of writes. cameras, etc are aware of this and cycle the write zone to evenly wear it down, but an os will simply write wherever whenever. perhaps the 2.5 drives cost more because they have a firmware-implemented sector rolling design?
You do NOT want to use a compact flash card for a read/write file system; they have a limited number of write cycles.
They do have limited life spans. but how many reads and writes is that? and how many days/weeks etc... would that be in a pc? perhaps for low usage machines? maybe something more along these lines when IBM finishes that magnetic ram...
Because they are more expensive! Why could you not work that out ? **GRIN**
"It is better to know that you have lost than to not know you have won"
You're thinking of a RAM drive. These usually present a SCSI interface, and are really horrendously expensive. Often used to accelerate database performance on mid-range ($100K) solaris servers.
There are a number of companies selling actual "flash" drives, both as CF-to-IDE harnesses and custom packaged in a laptop-drive form factor.
These are nothing like RAM drives, and in fact are not really any more sophisticated than your standard "Compact Flash" storage card.
Here's an example with some specs:c hip.htm
http://www.acal.be/products/el/active/sandisk/san
I have a couple of 64Mb models, you can often find them on Ebay at reasonable prices. I use them to build Diskless FreeBSD hosts.
I do not deploy Linux. Ever.
Flash memory can only be written to approx. 100,000 times in any one spot before it will fail. Flash drives (and compact flash) will try to distribute the load, but if you have anything running that is caching to the drive it can wear out quickly. So things like the tmp directory should go in RAM.
This article might be of some use as far as pricing such an item. Also pretty cool talking about setting up a solid state raid, which is pretty absurd as far as going with the concept of trying to increase the speed; but with access times below .1 ms, it seems pretty sbsurd.
This site seems to have a price on some surplus quantum rushmores, but i dont know what a good price on these are, and therefore dont know what a good price would be.
-D
Links courtesy of google.
For a quiet (fanless) low-powered and small but inexpensive and complete PC (utp,serial,parallel,usb,vga,tv-out, etc.) you might want to check out the OpenBrick
It boots off a Compact Flash card - FreeBSD and Mandrake images available, and optionally supports a HD
CompactFlash is produced in greater volume therefore it's cheaper. however CF to IDE adapters are about £20.
The problem (as people has said) is that any flashmem based device wears out. The best thing to do is find out the average throughput of the unit (assume all of that are writes, worst case) and look at the write/erase cycle life, from there you can make a guess and how long you'd have until bits started failing.
N.B. cheaper CF is often slower and fails quicker, be sure to check the stats before you buy.
Loop, twist and loop again.
A couple years ago i wanted to build a hard drive out of the old 4 MB sticks of EDO ram that were pilling up from old machines that had shuffeled off their mortal coil. The idea of a battery to keep the memory when the power was off (like CMOS) seemed to be totally practical.
I'm not an electrical engineer, but there has to be someone out there who can design a PCB (okay, that green board that the cpu & friends sit on) that's along the lines of "fun with electronics" so that people can program and construct the damn things themselves.
i know EDO is a bit out of date now, but with DDR well on its way maybe someone could do it with SDRAM?
And if not, why not?
USB has nothing to do with CompactFlash...
I have a CF->PCMCIA adapter - MUCH faster than a USB reader, and in fact indistinguishable from the much more expensive ATA PCMCIA cards.
CF cards have a built-in IDE interface, connecting them to an IDE bus is a matter of passive wiring. (There are adapters to do this for $10-20, MAYBE $30, but I'm positive it's not more than that. My CF-PCMCIA adapter cost me $10)
retrorocket.o not found, launch anyway?
I am going to guess that a momentary loss of attention caused c0ldfusion to write "solid state" memory when he or she meant "static" memory.