What is the best/fastest SD card to offer best speed ?

espskog · May 2nd 2021

Hi.

I use a Kingston 32GB SD card and I assume it's a bit old and slow cause my diskspeed feels a bit slow in Minimig. So I am gonna invest in a new SD card (also because my current SD card plastic case opened up accidentally.

But - what is considered the best option here to get e.g. 32GB and the fastest IO ? Is it a samsung, a sandisk or a kingston ...or something else ?

And what specs should I aim for. I want the best of the best and it has to be a MicroSD card (not fullsize) as I am gonna use it in an adapter.

Suggestions, advises are welcome

Tobias · May 2nd 2021

Since the SD interface is using the old bitbanged SPI interface - it probably doesnt matter.

espskog · May 2nd 2021

Ok. Can this old bitbanged SPI interface be improved in terms of speed or is it locked in with the current hardware design on the TC ?

robinsonb5 · May 2nd 2021

Even if the extra signals required for faster transfers were available, the Minimig core is tied quite closely to SPI - that's not likely to change any time soon.

(The original Minimig had a microcontroller, the SD card and several virtual peripherals in the FPGA core all sharing an SPI bus on the PCB. The Minimig core for Chameleon still uses that same logical structure, it's just that more of it is now inside the FPGA, and less of it - just the SD card and RTC - on the PCB.)

Tobias · May 3rd 2021

I don't know how the Minimig Core deals with it, so no idea. But the hardware is wired up for SPI, indeed