R/W speeds of cartridge?

[kijetesantakalu042]

I'm working on a project and I want to know how fast the 3ds can read the ROM and how fast it can write to the SPI flash (Savedata).

 

[linuxares]

I sadly don't know the answer, but just remember there is different speeds on them, since its different manufacturers of the nands and rams.

 

[kijetesantakalu042]

I sadly don't know the answer, but just remember there is different speeds on them, since its different manufacturers of the nands and rams.

I was asking what the highest speed the interface could go at. Still that answer gives me hope that it can go pretty fast.

 

[linuxares]

@SylverReZ Did you know this? Maybe it have the same speed as the DS?

 

[SylverReZ]

The R/W speeds from NAND and SPI EEPROM are fairly similar to the original DS.

 

[kijetesantakalu042]

The R/W speeds from NAND and SPI EEPROM are fairly similar to the original DS.

If I were to build a super speedy cartridge which had NAND and EEPROM that ran at infinite speed, how fast could the 3DS actually write to it?

 

[SylverReZ]

If I were to build a super speedy cartridge which had NAND and EEPROM that ran at infinite speed, how fast could the 3DS actually write to it?

The N-Card flashcarts acts the same way as a retail DS cartridge, has the same I/O in one ASIC COB blob. Doesn't have the best speeds for transferring and reading data through USB, though. For reading data from the NAND flash, a random read takes just around 50 nanoseconds according to the datasheets. Least it's much faster in comparison to the DS-Xtreme carts.

 

[kijetesantakalu042]

The N-Card flashcarts acts the same way as a retail DS cartridge, has the same I/O in one ASIC COB blob. Doesn't have the best speeds for transferring and reading data through USB, though. For reading data from the NAND flash, a random read takes just around 50 nanoseconds according to the datasheets. Least it's much faster in comparison to the DS-Xtreme carts.

While the chip used can handle 40 MB, can the DS/3DS actually read at that speed? It'd be nice if the 3DS could actually handle that speed but I doubt it.

I suspect no one really knows this info.

 

[ghjfdtg]

The maximum speed is somewhere around 16 MHz with 8 data lines. HOS never uses the maximum speed for CTRCARD. NTRCARD can only handle 6.7 MHz.

 

[kijetesantakalu042]

The maximum speed is somewhere around 16 MHz with 8 data lines. HOS never uses the maximum speed for CTRCARD. NTRCARD can only handle 6.7 MHz.

do you have source for that? (PLS i want to know more)

 

[ghjfdtg]

"CTRCARD Registers" below.
https://problemkaputt.de/gbatek-3ds-cartridge-registers.htm

 

[kijetesantakalu042]

"CTRCARD Registers" below.
https://problemkaputt.de/gbatek-3ds-cartridge-registers.htm

That isn't even related to the question...

 

[zxr750j]

Chatgpt:
The Nintendo 3DS's internal NAND flash storage typically has read speeds around 15–20 MB/s and write speeds of around 3–5 MB/s.

 

[kijetesantakalu042]

Chatgpt:
The Nintendo 3DS's internal NAND flash storage typically has read speeds around 15–20 MB/s and write speeds of around 3–5 MB/s.

that's not it either.

 

[zxr750j]

If I were to build a super speedy cartridge which had NAND and EEPROM that ran at infinite speed, how fast could the 3DS actually write to it?

The Nintendo 3DS has several bottlenecks that limit its data transfer speed to and from cartridges, even if the cartridge's storage could hypothetically operate at "infinite" speed:

1. Cartridge Interface Limitations: The 3DS uses a custom cartridge interface, which is not optimized for ultra-high-speed data transfer. Actual data transfer rates through this interface are around 10–15 MB/s, with peaks possibly hitting around 20 MB/s, but those peaks are rare and not always sustainable.
2. CPU and Memory Bus Constraints: The ARM11 and ARM9 processors, along with the 3DS’s memory architecture, impose limitations on how quickly data can be processed and written to memory. The 3DS’s CPU is not designed for high-throughput I/O operations, so data processing and transfer speeds are inherently capped by the CPU and bus speeds.
3. Software Overhead: The 3DS’s OS and software routines also add some overhead to read and write operations. Accessing data from a cartridge requires I/O routines to translate that into usable data for the system, which further slows down effective throughput.
4. Power Constraints: Running high-speed data operations continuously on a device like the 3DS could lead to thermal throttling or power-related issues, further reducing the speed of sustained write operations.

So even with an ideal, infinitely fast cartridge, the 3DS would likely cap out at around 15–20 MB/s for peak transfer speeds in best-case scenarios.

 

[kijetesantakalu042]

The Nintendo 3DS has several bottlenecks that limit its data transfer speed to and from cartridges, even if the cartridge's storage could hypothetically operate at "infinite" speed:

1. Cartridge Interface Limitations: The 3DS uses a custom cartridge interface, which is not optimized for ultra-high-speed data transfer. Actual data transfer rates through this interface are around 10–15 MB/s, with peaks possibly hitting around 20 MB/s, but those peaks are rare and not always sustainable.
2. CPU and Memory Bus Constraints: The ARM11 and ARM9 processors, along with the 3DS’s memory architecture, impose limitations on how quickly data can be processed and written to memory. The 3DS’s CPU is not designed for high-throughput I/O operations, so data processing and transfer speeds are inherently capped by the CPU and bus speeds.
3. Software Overhead: The 3DS’s OS and software routines also add some overhead to read and write operations. Accessing data from a cartridge requires I/O routines to translate that into usable data for the system, which further slows down effective throughput.
4. Power Constraints: Running high-speed data operations continuously on a device like the 3DS could lead to thermal throttling or power-related issues, further reducing the speed of sustained write operations.

So even with an ideal, infinitely fast cartridge, the 3DS would likely cap out at around 15–20 MB/s for peak transfer speeds in best-case scenarios.

I didn't go to GBATemp to have someone past my question into chatgpt

 

[Latiodile]

Chatgpt:

answer discarded.

 

[ghjfdtg]

That isn't even related to the question...

I don't know what is if not this documentation. Don't be lazy and do the math.
CTRCARD_CNT has a minimum clock divider of 4 which gives us 16.75 MHz which is 16.75 million bits per second for each data line and there are 8.
The total theoretical transfer speed is ~15.97 MB/s but due to overheads and delays from the underlying NAND flash you will never reach the maximum.

 

[kijetesantakalu042]

I don't know what is if not this documentation. Don't be lazy and do the math.
CTRCARD_CNT has a minimum clock divider of 4 which gives us 16.75 MHz which is 16.75 million bits per second for each data line and there are 8.
The total theoretical transfer speed is ~15.97 MB/s but due to overheads and delays from the underlying NAND flash you will never reach the maximum.

I sort of glanced over the page /:. I think that's the final answer I think.

 

[Joom]

I didn't go to GBATemp to have someone past my question into chatgpt

People seem to not know that GPT sources places like this for this kind of info, and then just regurgitates an overly generalized summary. It's absolutely useless for this kind of stuff, and it makes me hate things like Gemini since that's now the first thing you see when searching Google. I can't even find a song based on its lyrics thanks to that garbage.

/AI rant