File systems and SD swap speed questions.

[TitanUranus]

I have a couple of questions, I suspect the answer is no, but is there EXT4 support yet (or are we still in need of a kernel update?). My second question is related to filesystems of SDHC, what's the fastest filesystem we currently have? I'm going to try testing a fat32 partition for storing stuff on, and I'll increase the cluster size to 32k - will I notice a difference to EXT2/3 (I know EXT2 wears out flash less, but right now I'm interested in speed primarily write speed). Does increasing the cluster size to 4k in EXT or 32+ in fat32/NTFS help with speed? Finally, how good is swap memory management. I'm used to the OS running off SD, but would I notice a faster speed when using swap if I ran the OS from NAND and a 256mb swap on SD1 and a 256mb swap on SD2 as opposed to a single 512mb swap on SD2 with the OS booted and running from SD1?


Cheers folks.

 

[mcobit]

I think if you use swap you won't get any speed increase. It just allows you to run memory hungry apps.


If an app can use swap, it will especially firefox etc. Swapping is always slower than ram access, so if you don't need it to run and app, better don't use it!


As soon as an app is using swap, it will slow down ( compilers especially)


Edit: fastest supported filesystem may be ext2 or reiserfs, as they have no journal.

 

[TitanUranus]

Thanks mcobit. I was thinking that by running from NAND the OS files would be read from there which would leave the SD slots free from taking a speed hit reading them. Also, I had been hoping that by using 2 seperate 256mb swaps, one on each SD slot, it might share the reading and writing loads between the 2 cards increasing overall swap speed (ie it could write 10mb swap to card 1 at 10x speed, and another 10mb swap to card 2 also at 10x speed simultaneously. That would mean it could write 20mb swap 2 times faster than if it had to write 20mb swap to a single card).