But surely, they will make RAM SDDs a more noche products than earlier - for example huge WEB datacenters that used RAM SSDs will eventually drift to the flash ones

So, I don’t buy your lifespan argument…:-)

With the logging kind of application, I will be pleased to see it last 2-3 years.

On the contrary, I was paraphrasing Al’s own comment. His accomplishments speak for themselves.

Robin

So he must of be a little smarter and wiser then you give him credit for.

Using SSD for a log is of course very attractive if it means major reductions in access time. OTOH, for anything but pretty light-weight use a log often has to handle considerable bandwidth as well, either because there’s a hell of a lot going on - e.g., in large TPC-C submissions databases may need to stripe their logs across multiple disks to attain sufficient bandwidth - or because once you’ve got a log, it makes sense to dump all reasonably small updates into it temporarily to make them persistent, deferring final placement until they’re about to be thrown out of the cache (i.e., until they’ve ‘cooled off’ - thus catching multiple quick updates to the same data in the log rather than writing each one back to its normal location with, of course, additional log activity for that).

Thus the answer to your question is, “No, people don’t do 2K log writes these days - not with group commits and all sorts of other data being dumped into the log. In fact, log writes can be several hundred KB in size if a backlog develops.” And a possibly better way to look at a flash disk in terms of replacing a single conventional disk is in terms of bandwidth, say, 50 - 100 MB/sec these days (though I’m not sure current flash disks can handle that yet). At that rate, a 32 GB flash drive wrapped around 100K times would last a year or two.

But hey, you could stripe the log across several to get higher bandwidth or greater longevity - still at a cost far below conventional SSD. Or fall back to a log on a conventional disk if it failed (for that matter, *always* dump the log to conventional disk and just use the flash drive for bridge-persistence until it got there - to even out log bursts and eliminate disk-access latencies). So it’s still a good alternative to conventional SSDs for that purpose.

Unfortunately, many current uses of SSD are not log-structured but as band-aids to shore up otherwise inefficient storage practices - e.g., where a lot of potentially unnecessary disk updates are being performed and workload has risen to the point where this inefficiency can no longer be tolerated. How well flash memory would serve here (wherer bandwidth requirements may be far higher than most logs would ever see) is more questionable.

- bill

You sound like just the guy to decrypt the Colossal Storage disk drive explanation. Now he got Al Shugart to invest in the company, but as Al noted, he couldn’t understand what they were talking about either.

Perpetual motion machines will always be with us. So will incredible new storage technologies (I hope). Along with V8’s that get 90 MPG just by clipping a magnet on the fuel line. Of course the storage companies don’t want you know about it, they’d destroy their business!

A prophet is without honor in his own country. Then again, so is the nutcase - except when he holds high political office.

Robin

The text is below is the last segment of the page.

http://www.dansdata.com/danletters138.htm

Not quite up to John Titor standard
Is there such a thing as “non-volatile integrated quantum-optical RAM”? I found a Web site claiming gigantic amounts of storage stored in what looks to be an optical jewel of some sort. Their sites are Atom Chip and Compu-Technics, and they are supposedly at CES 2005.

Their Web sites are very poorly made, using what looks like pictures taken with a webcam or a very cheap digital camera, yet they boast 128MB/square millimeter on a 20 micron slab, accessible at 0.6ns, which is Really Fast, considering light goes about 30 cm in 1ns through air. Can you please look into the validity of these claims and said technology?

Jaren

Answer:
Is there such a technology? Uh, no.

The sites in question do, indeed, display numerous imperfections as evidence of their handcrafted nature. I don’t know exactly what kind of joke/art project/product of mental illness they are, but they certainly don’t rise to the status of an actual scam. This incredible breakthrough technology has, unaccountably, failed to attract any attention at all in the more than two years they’ve been promoting it, or in the six years since the mad scientist responsible patented what looks like the process allegedly involved.

This thread, which mentions the simply outstanding video clip you can download here, pretty much sums it up. The discussion is not unlike that one might expect if a bunch of automotive engineers found themselves unexpectedly discussing the feasibility of time-travelling DeLoreans.

Far be it from me, of course, to badmouth a technology so great it’s won what looks exactly like an Academy Award for “The complete innovation activity”. That is, I think, the most hilarious of the various awards the Compu-Technics technologies have received either because they paid for them (there are “award mills”, just like “diploma mills”, that’ve served the quack and kook communities for about as long as there’ve been quacks and kooks; you pays your money, you gets your certificate/medal/trophy), or because they turned up at some obscure trade show or convention and their wild claims were believed.

I’ve been looking for something like this for a long time.

I think of your writing like the line in the John Wayne/John Ford movie Rio Grande.
“Trooper Harris brought us the word. We came as soon as we could.”

When you think 100,000 cycles doesn’t sound much, but your numbers look reasonable. For laptops the average file size is probably larger - think internet browsing (html, jpg, flash files) usually ~ 20-50KB, so the flash will wear a bit faster.

By my obzerversions, the hard drive of the average sales manager’s laptop dies once a year, some time faster than that - so the flash still looks pretty cool even for not so esoteric applications.

At price 1K per drive compared to 2-3K for data recovery services it is pretty good if you ask me.

Add to this the read only dead cells (when it dies flash becomes read only) which allows you to still read/recover the data. The side effect to dead cells is that the drive will get smaller and smaller with more dead cells, but this is easy to get under control. Much easier than sudden dead hard drive.

Also, can you imagine how cool would be to run ZFS on flash drives!

There is also this company - Atomchip, not sure if you have seen the site or not, but this guys have 1TB quantum storage chips with the size of ~1″x1″.

http://atomchip.com/_wsn/page3.html

It looks pretty weird on the pictures, but I really hope it is true :))