[bergy]

Hi there Everybody ...

Are we going to have flash drives soon in our computers?

How will this effect hardware and software performance?

How far away is this development?

[OreoCookie]

Right now, flash drives are too expensive for mass market harddrive replacements. There are a few, but they are expensive and meant for particular applications.

The seek times are roughly one order of magnitude faster (typically less than 1 ms, compared to 8-9 ms for 7.2k rpm drives), but the sustained throughput is less (up to 30 MB/s sustained throughput for the current generation of harddrive replacements).

See here for an article about this topic.

[Millennium]

For the moment, there are three problems with flash (or other forms of solid-state storage technology) which keep them from being practical for use in hard drives: cost, performance, and longevity. At the moment, solid-state storage is practical for relatively small removable storage units, but these factors keep it from being a viable option for mass storage for the time being.

First off is the issue of cost. This is fairly easy: flash chips cost more per gigabyte than magnetic optical media. Acording to memorysuppliers.com, I can get a 6GB Flash drive for some $285. According to Western Digital's online store, I can get a consumer-grage 250GB hard drive for $109. By going magnet, I can get 42 times the capacity for less than half of the price. It's unlikely that flash chips will ever be truly cheaper than magnetic media, but in time they may become cheap enough to use as a boot drive. However, as long as people keep demanding more and more storage on their home computers, hard drives will reign supreme: they can just hold more for the same price.

Performance is another issue. Standard RAM is hundreds of times faster than a hard drive, but it requires a continuous stream of power or all the data gets erased; this obviously makes it impractical for mass storage. Flash, unlike standard RAM, doesn't lose any data when power is removed, but this comes at a price: it's much slower than standard RAM. It's still faster than optical media, but at this time it's slower than magnetic media. This is not a problem for the removable-storage devices we see today, where it's expected that the contents of the disk don't change often and they're not read often. As a boot drive, however, the system would become significantly slower. Disk I/O is already one of the major bottlenecks in computer performance today, and drives based on current flash technology would only make that problem worse. This may change in the future -it probably will, in fact- but it's not the current technological reality.

Finally, there's the problem of longevity. Most current flash technology can be written over about 10,000 times before it starts having trouble with reading and writing data on it. That may seem like a lot, and for the current applications of flash technology it is: you might write to a removable drive or memcard an average of 10 times a day if you use it heavily, and at that rate the card will last for some three years. However, boot drives are often written to hundreds of times a day, or even thousands of times, often without user intervention: virtual memory, temporary files, and browser-style caches are just some of the many ways that a filesystem can be written to even if the user isn't aware of it. At that rate, flash-based mass storage would fail much too soon. This, as with speed, is likely to improve as time goes on, but it's not there just yet.

What will the effects of solid-state storage be? Performance-wise, I don't actually think there's going to be much effect, at least not anytime soon. As I mentioned before, flash is still pretty slow, and it's unlikely to be significantly faster than hard drives for quite some time. However, if it speeds up enough, at least it won't be any slower.

The real gains will be in reliability and energy savings. Hard drives have many moving parts: platters, heads, and other devices, and all of these have to be powered by motors. Every one of these things is a moving part which can break if jarred in just the wrong way. Flash drives, on the other hand, need not have any moving parts at all, and this allows them to be made considerably more rugged. Motors also require a lot of power to operate: take them out, and and you can save quite a lot of energy. A third side effect, which will probably be more applicable to set-top devices, is noise: hard drives require sound-dampening devices to run quietly, but flash drives can be truly silent.

As for when solid-state mass storage will exist: it already does. Even today, you can buy flash drives in the same form factors as hard drives. They'll even plug right into an existing SCSI, ATA, or other setup: the computer never even knows that you're using a different sort of mass storage. However, be prepared to pay for it: these things are very expensive.

[Horsepoo!!!]

What we may see in the near future is a hybrid flash/magnetic drive.

[OreoCookie]

Just a note: RAM-based solid-state storage system are known for years now and are extremely fast and very expensive. As they use standard RAM, they are supposed to provide limited space for 3d models or so when you need the absolutely highest speed (in particular seek times, but also throughput).

Since the memory is volatile, you either have a backup battery, a backup harddrive or both. But this is a different animal. I think in the foreseeable future, we will see flash-based harddrive replacements, as soon as they offer `enough' capacity for the average user (take a look at the iPod nano, five years ago, this would have been impossible). I would also like to add to Millenium's list of pros that flash-based drives allow for small laptops.

[bergy]

Here's something interesting today from macdaily news on this topic ...

http://macdailynews.com/index.php/weblog/comments/8069/

"Although Intel only demonstrated its Robson cache technology in the fourth quarter of last year, sources now claim that Apple Computer will launch a notebook computer in the middle of this month that utilizes the NAND flash based cache memory technology," Hans Wu, Danny Kuo and Esther Lam report for DigiTimes. "The sources did not say which line of Apple notebooks would implement the technology, and Apple Taiwan was not available for comment at the time of publication."

"Robson cache technology relies on NAND flash instead of a traditional hard disk drive (HDD) for starting up a computer or launching frequently used applications, and thus is able to significantly improve the computer’s boot up time, as well as battery life. Intel demonstrated the technology with a Centrino-based notebook during the Intel Developer Forum Taipei in October 2005," Wu, Kuo and Lam report.

[Catfish_Man]

Wake me when I can get an 80GB 1T sram drive

[tooki]

AHEM... this is a discussion of Mac OS X how, exactly? Oh, that's right, it's not!

tooki