Hacking SD Card speeds for installing CIA

[Disco]

N3DS testing proved I was right indeed!

So, both N3DS and old 3DS started exactly at the same time (I was using once again Link Between Worlds CIA which is cca 720mb in size), N3DS started slow but as time passed, the difference was bigger.
In the end N3DS finished when old 3DS was on 78% of game installation so it's 22% difference! I presume that on bigger games (RE:R for example) the difference is even bigger.

Also in the old 3DS I have TDK class 10 32gb microSD in adapter which has 12mb/s writing speed, and in N3DS is the original Toshiba 4gb mSD class 4 which also has 12mb/s writing speed (obviously N is using some quality cards here).

So if someone has some faster card, please post your results

 

[SomecallmeBerto]

Really cool....must be because of the better tech

 

[GaaraPrime]

Appreciate the effort Disco dude

 

[themperror]

I don't think the 3ds is limited by SD Slot speed, I think it's the decryption/CPU speed that limits it, I have a 100MB/s read/write SD card and it still takes a while, I think the number mentioned in this thread are about right (normal 3DS XL). The only real benefit it will have is transferring games onto them (or cia's)..

 

[Kohmei]

Now we just need a devmenu that supports the 2 extra cores

 

[apoptygma]

I also now timed installation of Link Between Worlds which is 714mb, it took 12:40mins.
And that translate to atrocious 0.9-1mb/s of write speed. Thats super slow.

According to mathematics, that would take cca 1h to install RE:Revelations which is cca 3,4gb

You forgot one major factor. Your SD is both the source and destination for the processing. If you were going from another medium (ie. A game cartridge) to the SD your math works. Try dumping a retail cart if you want a proper test.

 

[apoptygma]

Now we just need a devmenu that supports the 2 extra cores

You may be right actually...

 

[apoptygma]

I don't think the 3ds is limited by SD Slot speed, I think it's the decryption/CPU speed that limits it, I have a 100MB/s read/write SD card and it still takes a while, I think the number mentioned in this thread are about right (normal 3DS XL). The only real benefit it will have is transferring games onto them (or cia's)..

CIAs aren't encrypted are they? . Isn't the decryption is done in the process of conversion from .3ds to .cia

 

[themperror]

CIAs aren't encrypted are they? . Isn't the decryption is done in the process of conversion from .3ds to .cia

As gamesquest1 said: "i think its just how the 3ds installs them, not that the SD cant read/write faster, i think its basically loaded up and written in small chunks, similar to how the original ncch decryptor worked"

Thus yeah the "extracting / de-chunking / whatever" takes alot of CPU power, thus not being capped by the SD write speeds but by raw CPU power, which explains why the N3DS does it better. And this makes very much sense..

 

[aos10]

the cia install are the same , it always the same ( on OG 3DS )
but , there is really huge deference between class 4 and class 10 on emunand or gateway or sky3DS
when i was using class 4 , the 3DS need 1 min to boot , when exiting any game it take 20 sec
but after i switch to really speedy card , it took me 3 sec to exit any game

 

[Disco]

the cia install are the same , it always the same ( on OG 3DS )
but , there is really huge deference between class 4 and class 10 on emunand or gateway or sky3DS
when i was using class 4 , the 3DS need 1 min to boot , when exiting any game it take 20 sec
but after i switch to really speedy card , it took me 3 sec to exit any game

Well, this is something new to me, thanks!

 

[gamesquest1]

CIAs aren't encrypted are they? . Isn't the decryption is done in the process of conversion from .3ds to .cia

they actually are being encrypted as they install to the SD card using the console unique encryption which is used for all content stored on the SD card, and they are actually still encrypted too during the conversion, but they are encrypted with zerokeys.....only way i see this getting any faster is if someone makes a CFW that just does away with all the encryption/decryption so you could put a purely decrypted rom on there, then the installation would probably be done in about the same time as it would take to copy a file from the SD onto the same SD card, the bottleneck is likely the encryption as its being encrypted to be stored to the SD

 

[apoptygma]

they actually are being encrypted as they install to the SD card using the console unique encryption which is used for all content stored on the SD card, and they are actually still encrypted too during the conversion, but they are encrypted with zerokeys.....only way i see this getting any faster is if someone makes a CFW that just does away with all the encryption/decryption so you could put a purely decrypted rom on there, then the installation would probably be done in about the same time as it would take to copy a file from the SD onto the same SD card, the bottleneck is likely the encryption as its being encrypted to be stored to the SD

Makes sense. Good info thanks.

 

[olec04]

My sd is really bad then