@CTCaer Do you know what the 'real world' speed limit is on the SDCard slot? I have been using a SamEvo 128gb UHCC1 from 2016. It tests about 75/20mb. Its worked pretty well and my Nand backup/verify time took like 84min. It looks like these newer UHC3 cards are getting much faster write speeds 70=80mb but not much faster reads 90-100mb. In talking to someone doing a Nand backup/verify last night to a UHC3 card they were probably going to get thru it in about 50-55min, so apparently the faster write speeds will help with Nand dumps and .nsp installs.
So anyways just curious on read speeds in particular (as it relates to load times) in the SD slot, at what range will we likely not see much performance difference (is 80mb about it), and does the internal flash have more bus lanes or is it just really fast memory? There are a few games that installing internal makes a significant difference, I suspect its because they use lots of small_file assets making the large cluster size of SDcards less than ideal? Do we know how what file system the internal uses? Any thoughts on that from what you have learned so far would be appreciated and thank you for the work you are contributing for this super exciting scene.
The switch speed limit is 104MB/s raw.
In hekate the RAM is untrained and this reduces the speed to about 24MB/s.
If you include the execution time this falls more, to around 18-22MB/s.
So the backup/verify will not help you test it.
Now the real world test.
What you are testing is wrong. The sequential read does not play a big role.
U1 vs U3: there's a great deal in this.
U1 means 10MB/s minimum speed at all times (seq or random).
U3 means 30MB/s minimum.
So when a game starts loading assets from here and there, the loading times will be a great deal better on a U3 card.
And it's not the cluster size. The cluster size helps. If you write 1 small file it will still take a whole cluster.
And because the read is the whole cluster this makes it faster than having let's say 512B cluster. That's why exFAT is faster. Because 128KB cluster size.
It's about fs cluster size vs sd card physical block size.
Anyway for compatibility this is true: FAT32 /w 32KB cluster size. exFAT /w 128KB cluster size.
The internal emmc and its buss are way faster than a sd card with a UHS-I bus. Both in speed and I/O throughput.
Not even a UHS-II card with a UHS-II bus or card reader can win the eMMC.
The eMMC uses FAT32 for SYSTEM and USER. But this doesn't play a big role if you have such a fast bus and chip.
TL;DR:
The best speeds in switch can only be achieved with a UHS-I or UHS-II card that is U3 compatible.
(The UHS-II card will fallback to UHS-I, but its chip is very fast and will help with random accesses.)
For filesystem it's exFAT 128KB.
(Except if you have a buggy switch fw version and you should use FAT32 32KB to avoid corruptions.)