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Benson's Avatar
Posts: 4,930 | Thanked: 2,272 times | Joined on Oct 2007
#55
Originally Posted by jibanes View Post
I also suggest some random i/o patterns rather than sequential i/o, but most importantly what would be REALLY useful is to know how many writes such or such card or brand or type of card allow, it's flash technology, therefore it has a limited amount of write cycles available, which obviously is clearly not advertised, and these numbers vary quite a lot from constructor to constructor (and often from same cards from the same manufacturer, but different revision numbers). But performing such tests are indeed destructive, although that'd be worth it.

Benchmarks in sequential i/o are somewhat useless, because as long as the card is fast enough to play a movie (the contrary would be surprising) then it's fast enough for anything you would want to do that involves sequential i/o on a flash card (unless if you're intending to put a database on such card and do some table scans). Random i/o is probably closer to what people are using these cards for. If you're just storing movies on such card, then maybe, just maybe you bought the wrong kind of device, and you should have looked for some video ipod or anything (archos, creative zen...?) preferably with a harddrive. Because the point of storing 10 movies on a card is somewhat meaningless (that's when streaming media is usually more valuable than reading from the flash card); and needless to say, the cost of a 12GB/8GB card is almost as high as the cost of 10 dvds.

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Now, let me ask the N810 community, what do you intend to use your 6GB+ flash card for? Now don't get me wrong, it's fine to have your favorite movie on your flash card (as long as it's "Wargames"), I'm just saying that it somewhat defeats the purpose of flash memory.
First, Flash is about as fast at random as sequential access -- it's slower than RAM by enough that loading whole addresses instead of increments isn't a major penalty, and it's not like a disk where pulling a long stream of bits off as the disk goes can be is bus-saturatingly fast, but spinning the disk a different speed (for CLV disks) and slewing the head to the new track is slow. So the benchmarks should be fairly reliable, and definitely a fair comparison between units. Any random access penalty will be bus-dependent, and thus "fair".

What I use a 6GB+ flash card for (in my N800, I don't have an N810 ? Well, I've had it for ~2 months, and I've got:
~160 MB - Manual backup of OS2008 root partition (so I could recover manually installed progs and stuff)
~540 MB - Music, MP3s, mainly >=128kbps. More coming, but I haven't got it on yet.
~300 MB - Maemo Mapper dbs, some of world, US, state, and local area at various (appropriate) zoom levels. Still haven't downloaded all the maps I want, as I can only do this with strong wifi and plugged in. (I've only got stuff from one repo, at present, so multiply x5 or so just to get all the repos I want, much less the areas I haven't got yet.)
Total, ~1.2 GB, but it'll be a lot more with more music and WAY MORE maps. The maps, I think, are a big thing. With the N810's GPS, Maemo Mapper would be even more useful. And I want a lot of maps available.