Friday, September 12, 2008

Flash prices (was: RAM prices)

I've ordered a Nikon D90 with UK dealer AJ Purdy, and they throw in two 4GB SD cards with the sale. How very nice of them, that's a good deal, I thought. And then I happened to look these cards up, and guess what they cost? Six pounds each!
Holy crap. I remember the first memory card I bought back in 2000. I think it was 64MB, and it was something like £170. Man, these things have dropped in a hurry! That's about 1/2000 of the price per MB in eight years.
I have stopped deleting pictures from the cards, I just fill them up and keep them as extra backup. That said, I haven't yet managed to fill up card recently!

By the way, unlike many gadgets, the Nikon camera is not spectacularly cheaper if bought in the US compared to the UK. Otherwise I might have ordered from Amazon USA. They will only ship to a US address, but I use a service I think TTL pointed me to originally, AccessUSA (MyUS.com). This service works great. They have lots of experience sending abroad with the least amount of cost and hassle with customs etc.

12 comments:

Bert said...

"RAM prices"

Strictly speaking, you're talking about Flash ROM cards, not RAM... ;-)

Eolake Stobblehouse said...

Surely it's "Flash RAM"? It's not Read Only Memory, since you can write to it.

Bert said...

I'm afraid not. Whether a given type of memory is classified as RAM or ROM has very technical roots, but the general idea is that RAM loses its contents when power is removed, while ROM contents is permanent (until erased, that is).

I actually should have written Flash EPROM, for "Erasable Programmable Read-Only Memory". Trust me on this, there's a world of difference with RAM, aside from semantics. You actually have to erase the device (completely or partially) before writing to it, and writing requires a more-or-less complex programming algorithm to be carried out, hence the speed penalty for writing vs. reading.

Eolake Stobblehouse said...

So the camera erases and re-writes everything on the card every time I take a picture?

Bert said...

Not everything. Modern Flash devices are segmented into blocks. I honestly have no idea of how big such a block would be in a dedicated memory card, because these now use devices developed specifically for that application, and I would have to search a bit to find the relevant data.

But the idea is as follows: when you format the card, it is erased completely and a new, empty file structure is created. Then the card is filled up sequentially, one file at a time, until it is either full or you start deleting stuff.

When you delete a file, the space is reclaimed by erasing only those blocks that are fully occupied by the said file. The remaining block fragment(s) can either be reclaimed immediately by moving the remaining valid data in the fragment(s) to an empty block and erasing the old location, or simply tagged as invalid, to be reclaimed later in a subsequent garbage collection run. The exact behavior really depends on the system used, and whether or not some RAM is available to temporarily hold data while a block is being erased.

In this way, it really mimics a file storage system on a hard disk, with some precautions taken to ensure even wear of the blocks (the devices do age with every erase cycle).

Anonymous said...

It's definitely amazing how much prices of digital devices have come down. I paid almost $2K for an Olympus E-10 three weeks after it came out - I still have and use it, but it's only a 4MP camera. Great lenses though - I guess someone had to help them pay for their R&D expenses...

Eolake Stobblehouse said...

Thanks, Bert.

KY, are you considering a newer Olympus?

Anonymous said...

I bought my Nikon from Ritz but used
Bongo International http://BongoUS.com instead of AccessUSA


I think their website is more user-friendly and they gave me a better shipping price too

Eolake Stobblehouse said...

Well, the site certainly is prettier.
Thanks, this is good to know if I ever get problems with AccessUSA.

Eolake Stobblehouse said...

Anabellapena, does Bongo also make a "creative" invoice to save the customer import tax?

Eolake Stobblehouse said...

Anabellapena, does Bongo also make a "creative" invoice to save the customer import tax?

Anonymous said...

It is good to hear there are competitors to AccessUSA. I wouldn't necessarily put too much weight on the "prettiness" or even "user-friendliness" of the site, though, in this kind of service.

BongoUS.com, the domain name, was registered in June, 2007. AccessUSA has been around since 1995. In shipping, customs, etc. what counts more than anything else is experience and reliability.

If BongoUS is still around after this recession, I'll take a look.