Diy Sdxc Mod

[MonkeyChops]

3 cards for just amiga games? do they even make cards that small anymore? I do like the idea though, someone was making sd card labels for that kind of setup awhile back.

Maybe. I have 24G of amiga emulation stuff, and I by no means have it all. So unless I buy 32G cards (I won't yet, 16 are so much cheaper), I'm on the way to 3

opps, I'm letting my amiga ignorance show :blush:

 

[Alec]

Somehow, I fit without a problem on my 40 GB partition...

I do have another, but it's filled with a bunch of junk I don't really need (mostly 8-GB raw DVD images) which I access at most once in 2 months, and a windows partition which I boot into about twice a year.

So... If I buy two 32 GB SD cards, that will probably be too much for me. :lol:
(I'll probably buy a slow 32 GB card and a fast but smaller card)

 

[second exodous]

What kind of speed do you get with a USB reader with a class 6 SD card? My 16GB Transcend card, class 6, maxes out USB at around 24 MB/s. I say max out because my external HD does 24 MB/s on any computers through USB but the same drive on eSATA is 60 MB/s on every computer I've tried so I think my SD card maxes USB out.

Anyway, from my experience the bottle neck of the speed of anything is USB 2.0, never the actual device (hard drive, SDHC, thumb drive). So if you plan to use USB on the Pandora you're capped at USB 2.0, pretty much every class 6 card maxes that out. On this wiki page it caps the fastest SDHC card at 45 MB/s, way faster than my experiences with USB. This wiki page on USB says the 2.0 spec is up to 60 MB/s, I've never seen that though.

Just for fun I ordered this this to see if I can get over 24 MB/s with my card. I also want a card reader in my computer permanently and I can mod this nice into my floppy port, I already have all the front ports so I didn't really need one of those all in one drive bay things.

Anyway, speed shouldn't be that big of a concern, the only time you really need speed is when you move data from one card to another or put it into your computer to load games/music/movies. I kinda get annoyed when I go to load 10+ gigs on my SD card for my GP2X, thinking I should be getting more than the USB bottle neck, but patience is a virtue.

Storage capacity is a concern though, 64GB is what the ipod touch has right now so the potential of the Pandora is on par with current solid state devices. in X amount of years the Pandora 2 will come out and I'm sure it will have the current card storage technology, so I'm fine with the limitations of SDHC for now.

 

[Squidge]

Yes, the spec says upto 60MB/sec (but redefines 1MB as 1,000,000 bytes, so it's really 57.22MB), but regardless that is marketing speak as you can never use up all the bandwidth on USB - Firstly, slaves can't talk unless they are spoken to by the master, secondly there is much more data sent than just the file you are copying. Last the USB bus data is split up into frames on the bus which are time dependent. If you can't stuff all your data onto the bus in time (or rather, into the usb controllers buffers AND it stuff them onto the bus), then you have to wait (queue the data) until the next frame.

I'd guess that data per second throughput (assuming no other devices on USB) would max out at about half of what the spec says, perhaps a little more - 35MB/sec.

 

[Jourdy288]

Storage capacity is a concern though, 64GB is what the ipod touch has right now so the potential of the Pandora is on par with current solid state devices. in X amount of years the Pandora 2 will come out and I'm sure it will have the current card storage technology, so I'm fine with the limitations of SDHC for now.

Pandora 2 = 5 Years[sup]tm[/sup]

I think that we'll be OK until then, though, and again, regarding storage, the more the better.
Just a quick n00bs question, is it possible to use empty space on an SD card for RAM?

 

[second exodous]

. . .slaves can't talk unless they are spoken to by the master, secondly there is much more data sent than just the file you are copying. Last the USB bus data is split up into frames on the bus which are time dependent. If you can't stuff all your data onto the bus in time (or rather, into the usb controllers buffers AND it stuff them onto the bus), then you have to wait (queue the data) until the next frame.

Yeah, I didn't know what exactly was happening, I kinda read some of the wiki about motherboards having multiple USB buses.

I'd guess that data per second throughput (assuming no other devices on USB) would max out at about half of what the spec says, perhaps a little more - 35MB/sec.

I've never gotten above 24 or 25 MB/sec, but that may just be my SD reader and my external HDs. I think with the new SATA standard coming out it might become the de facto standard for storage in the future. eSATA is great, it's just not powered, I hope they fix that next revision. I read somewhere that it is coming sooner than later since the solid state drives are getting closer to maxing it out already. I only have my SD reader that is USB, everything else is eSATA and firewire with my current computer. After I get that SATA SD reader I'll be totally USB free as far as storage goes.

 

[Etinin]

Honestly two 32 GB SDHC cards is more than enough. You can put hundreds of games and dozens of movies on that

"640kb ought to be enough for anybody."


XD Sorry, I just had to...

Funny thing is that this guy said 640*10^5 KB ought to be enough for anybody.

 

[valhalla]

Just a quick n00bs question, is it possible to use empty space on an SD card for RAM?

It can be used as swap but it will be slow and with time it will damage the SD card.

 

[Tor]

Just a quick n00bs question, is it possible to use empty space on an SD card for RAM?

It can be used as swap but it will be slow and with time it will damage the SD card.

That is way too harsh. Many Nokia tablet users have used a swap file on an SD card for what amounts to years now. I've done so myself for a while now too.

A swap file on an SD card isn't there to improve performance (as you would expect by having more RAM), it's there to take the occasional overflow: Visit a web page that turns out to have lots of pictures, or something else that makes the page way more memory heavy than your current setup expected (maybe you have lots of other applications up and running already).

That heavy web page can be enough to tip you over the amount of RAM you have. With no swap you will crash and burn, i.e. the operating system will kill one or more applications. With a swap file in place the excess will instead overflow into the swap file and you'll survive the experience. For this purpose a swap file on an SD card works very well indeed. What's negative is that you have a file open on the SD card, so you must be careful before removing or replacing the card. This is less of a problem on a Nokia tablet than on the Pandora, because the Nokia tablets have a little magnetic sensor on the back cover (where the internal SD card is, on the N800), and just by opening the cover the device will turn off the swap file (if possible, if not it will tell you so), and unmount the card.

What I see from my experiences with swap-on-SD on my N800 is that most of the time the swap is empty or very nearly empty, and there is very little SD activity there. So no worries about burning out the SD card. It's just nice to have as a security net: Nothing is more annoying than processes getting killed.

The Pandora has twice the amount of RAM compared to the Nokia N8x0 tablets, and will have much less need for a swap file though (this can of course change if you run much heavier applications).

 

[levi]

I suspect you'll notice you're running out of RAM before the OS has to kill anything (though why would it do that? It would surely just deny memallocs, which admittedly could crash badly written apps). My Eee PC gets very slow if you use up all the ram because it can't use the remaining RAM for disc caching any more, and the SSDs in mine aren't exactly speedy.

I've disabled swap on my eee pc (and upped the RAM to 2GB, just so I can run a couple of web browsers and GIMP at the same time), but I'm a little worried about the log files. The main log gets written to every couple of minutes (though if that's cached to any significant effect) and the machine runs 24/7 which means you're getting thousands of write ops to the same file every week. From memory, most non-wear-levelling flash only handles a few tens of thousands of ops (specifically, its MTBF is somewhere around there).

I've been meaning to hack the init scripts to remount etc/logs as memfs early in the boot, and to copy the log files out of there to somewhere on disc on shutdown, but I haven't got round to it (and that solution isn't ideal if you need to diagnose a bug that's locking up your machine).

 

[pelrun]

I suspect you'll notice you're running out of RAM before the OS has to kill anything (though why would it do that? It would surely just deny memallocs, which admittedly could crash badly written apps). My Eee PC gets very slow if you use up all the ram because it can't use the remaining RAM for disc caching any more, and the SSDs in mine aren't exactly speedy.

You obviously haven't run swapless much. Linux will kill a process to free up memory if you run out; I can't remember whether it's a random choice or dependent on mem use. If you've got any swap at all then you'll probably never see it happen.

 

[levi]

I've been running swapless for about six months now, so not that long, no. But like I said, I notice well before it runs out of physical memory that it's having problems, and then I usually kill something manually. Now that I've got 2GB in the machine, I don't run out of memory very often at all, of course.