Archive for the ‘General Discussion’ Category

FullFAT 0.90 Pre-Release Now Available

Friday, June 12th, 2009

See http://code.google.com/p/fullfat/ for more information.

James

FullFAT – Read-Only BETA Officially Released

Thursday, March 12th, 2009

I’ve just made the first official release of FullFAT. Its a read-only preview BETA. You can download it from FullFAT’s googlecode page:

http://fullfat.googlecode.com

If you have any questions or problems using FullFAT please get in touch, (see Contact page) and let me know whats working, whats not.

I will try and help solve any problems via email.

Currently FullFAT compiles with the following compilers with no problems:

BlackFIN,
GCC
MSVC++
Renesas Compiler
Fujitsu Compiler

FullFAT Read Performance

Thursday, March 12th, 2009

I now have some pre-liminary read performance tests. In comparison to the EFSL library.

Results shown involve copying a 3MB file to a Ram Disk.

With a cache size of 512 (the smallest possible size):

Cache Size (Num Sectors) 512 (1) 1024 (2) 2048 (4) 4096 (8) 8192 (16) 16384 (32)
FullFAT (Kb/s) 1255.05 1082.50 1076.69 1075.68 1055.77 1050.97
EFSL     (Kb/s) 1065.56 1067.63 1062.02 1058.05 1024.28 1017.48

You can see that both systems degrade in performance slightly as the cache size increases. Caching really improves writing speed and thus provides an overall benefit, we shall see how FullFAT compares in this respect when writing has been implemented.

I shall try to optimise the reading of FullFAT further, and the caching system is due to be overhauled or even replaced for write functionality. There’s a great possibility that this can go even faster.

The test system used a Blackfin 537 processor, and a Kingston 512Mb SD Card via an SPI interface.

Note. Different systems will behave very differently, the speeds shown are for an SD card, and both file-systems could perform better, or worse with different media types.