What is the theortical limit to the amount of memory that can be stored on a standard USB flash drive?
The first one I bought was 512MB. My lastest is 2GB. I’ve seen some that are 32GB.
If they can get them to hold enough memory and get the price down will they replace standard hard drives?
You said “zip drive”, but your question is about USB flash drives. Different animal.
There are a few companies making SCSI, IDE or SATA compatible flash drives intended to simply replace your HDD. In HDD comparable sizes, they are damned expensive (thousands of dollars) the last time I looked.
Here’s one such - this is the page for their 3.5 flash IDE drive. They make 2.5 drives as well, and SCSI and SATA interfaces. You can get the 3.5 in sizes up to 78G:
http://www.bitmicro.com/products_edisk_35_ide.php
Currently, high prices make these suitable mostly for environments requiring ruggedized computers, where a conventional hard drive would get trashed.
As for a “Zip drive”, i.e. something which keeps all it’s data compressed, I don’t think that there’s a big future for these. The main problem is that the stuff filling most of people’s computers is MP3s and images. Both music and image files already generally use compressed formats, so when you try to compress them further, there is generally little change (and sometimes the data might even become larger.)
I’m sure someone will jump in here an correct me if I’m wrong, but I think we’ve got three different technologies being discussed here: Zip drives, flash drives and USB micro hard drives.
Zip drives, which were basically souped-up floppy drives were either 100 or 250MB, as I recall. I haven’t seen one of these (new) in years.
Flash drives, which use flash memory (and have no moving parts), Ive seen as large as, I think, 8GB.
USB hard drives are basically small-scale hard drives (spinning disks, read/write heads, etc). I think I’ve seen those at the 32GB size. They’re less durable than the flash drives, but can come in larger sizes…
I hope that’s helped rather than further confused the issue.
I’m discussing actual flash (solid state, no spinning disk) drives as HDD replacements. They DO come in HDD sizes, but, as I noted, are very expensive. If the OP was actually thinking of microdrives, that distinction should be made also.
I think you’re a little confused here. The Iomega Zip drive is unrelated to the Zip compression format. A Zip disk is about the same shape as a floppy disk, but thicker. They came in 100 MB and 250 MB sizes. Ever since the “Click of Death” became known (which involved the drive physically destroying the disks), Zip disks have fallen from use.
As for the OP, as far as the user is concerned, a USB flash drive and a USB hard drive are used identically. The underlying technology differs, though. A USB hard disk’s capacity can be as big or small as any standard hard drive, because that’s what’s inside of them. You can buy empty USB drive enclosures that allow you to supply your own hard drive in any capacity you can buy. USB hard disks are faster than a flash drive, but require more power, are less portable, and are way more fragile.
I had to do a little searching, but I found one . Wow. I stand corrected.
Wonder if I can convince my boss tat we need to buy a few?
Doh. I coulda sworn that the external hard-drive things that were compressed were called Zip Drives (and didn’t have any sort of ejectable disk), but ah well.
Nothing to see here folks! Move on through!
Something I recal hearing about was a hybrid drive, using platters for the bulk of the storage, and nonvolatile solid-state memory for the boot manager, drivers, and OS for minimum delay in startup.
That one’s still a USB drive. The example I provided a link to is one of a few companies making flash drives in HDD formats so that you can fit them directly into your desktop or laptop as the primary drive, install your OS on it, and boot off it. Your BIOS will think it’s an ordinary IDE or SATA drive. Got several thousand bucks to spend on your next drive?
I seem to recall that there may be problems with frequent rewriting of flash storage, too, which might be problematic for your “solid state” disk replacement. However, if you want to operate your laptop while in a tank, or something like this …
This is what I’m talking about. Is there a theoretical limit to what can fit in this space? Will they ever become economical enough to replace traditional hard drives? I’m not sure, with all the confusion, if this question has been answered.
The theoretical data density limit is hard to say. If you assume the physical limit of one atom per bit in a 2 cc volume, you get a theoretical limit on the order of (wild-ass estimation using diamond as the material) 6 g of diamond = 3 x 10[sup]23[/sup] atoms = 2[sup]80[/sup] bits = Yottabits. The prefixes go Giga, Tera, Peta, Exa, Zetta, Yotta, each one a 1000-fold increase over the previous so that’s a pretty absurd number to consider. Certainly, by the time technology gets there, that little thumb drive will hold a good portion of the average Slashdotter’s porn collection.
Of course, there are lots of limitations that are keeping us away from one bit per atom right now. One or more of them may prove to be insurmountable. Or, we might find that we can store more than one bit per atom, and the numbers listed above will be just a drop in the bucket. I imagine there’s some sort of information-theory theoretical entropy calculation that could be made, but I don’t know how to make it.
Flash memory (or other solid state storage) will probably become economical enough to replace hard drives, at least for many uses. Even if it doesn’t entirely replace magnetic hard disks, it’ll become part of the memory heirarchy (cache -> RAM -> Flash -> Disk). For many uses, it will completely replace the hard drive even if it doesn’t ever become cheaper per byte than the disks, simply because it’s faster, consumes less power, and is more reliable.
Anecdote along these lines, file under “Stuff I Never Thought I’d See.”:
A couple of months ago the IT guys came by my class to replace the hard drive on my computer. Seems the ones we’d had installed originally were North Korean surplus or something, and given over to catastrophic failure. I was in the middle of a lecture so I didn’t watch carefully, but they transferred my entire HD to a USB Flash, pulled the old HD, installed the new one and transferred back all of my data and programs in the time it took be to cover the events of Bastille Day.
If data storage gets any better, we will be talking about molecular storage.
Theoretical limit is probably there in terms of maximum read/write speed as well as maximum density using current technological limitations. These things are typically NAND or NOR flash on the inside (to the best of my knowledge), which are a type of integrated circuits. Last time I heard Samsung was using 50-nm process or even smaller to make its NAND. I don’t remember exact densities but the orders of magnitude we’re talking about are in hundreds of megabit per square millimeter.
So, yes, there are always theoretical limits but the technology is changing almost every year making those theoretical limits obsolete. There are hard limits on the amount of information that can be packed into physical space that draw on quantum mechanics, but we’re nowhere near that with flash drives.
Why are you guys wasting time with those weiner sized Flash Drives? Say hello to daddy. 
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The thumb drives, at least the ones that fit my budget, tend to be pretty slow on the write side of the equation. Also, they have limited write cycles. This matters a lot for HDD replacement consideration, as virtual memory operating systems (pretty much anything except QNX or RTX) are constantly banging applications in and out of the swap files.
Hm… Cleophus seems to be saying that a drive based on spinning-disk technology is faster than flash, but (:3= seems to be saying the reverse. Could someone clear that up?
Interestingly, and contrary to many peoples expectations, a platter based + cache memory hard drive is (overall) faster than a flash drive. Flash drives reads are potentially faster than a platter based drive, but writes and erase-writes with flash drives are consdierably slower due to the nature of flash architecture.
Also, a hard drive will stream data faster, but a flash drive has a lower seek time. So you may be able to stream one large file off a hard drive faster, but if you are trying to load a number of different little files into memory from various storage locations, flash may be faster.