Good news guys, I just got my A-Data card in the mail!!!
nice way to start a monday
I took out my old card, I found it was a class 2 8GB, came with phone.
I'm copying all the files to a folder on my pc, then I will let the phone format the card for me, (as it may use a different default cluster size than windows, I'm curious to see. Plus it may be faster or slower, so knowing that I can format with my pc if needed.)
Then I will copy the card contents back and post the benchmarks!
Results:
A little more mixed up here, What I gather is that the phone was doing some background I/O and this makes for fluxuations. Either way, the max value you saw is the most possible.
I can gather this much,
Bigger cache makes writes faster at first, then slower the more you go up
Reads get faster and faster, past a point it seems to maybe be trying to read too much ahead slowing things down a bit.
Benchmarks results for new card:
Cache Write Read
128 18.8 12.9
1024 18.4 22
2048 18 25.9
2304 15.1 26.2
2432 19 26.3 << Best avereges so far
3720 13.8 24.2
4096 18.6 27.7 < got fastest read scrore, but not consistently
To sum it up:
Class 2, 8GB (tweak 512 cache) = Write: 5.1 MB/s, Read: 16.1 MB/s (**correction: actually default was slower, 128)
Class 2, 8GB (tweak 3072 cache) = Write: 10.3 MB/s Read 26.2 MB/s
Class 10, 16GB (defualt 128 cache) = Write: 18.8 MB/s, Read: 12.9 MB/s
Class 10, 16GB (tweak 2432 cache) = Write: 19.0 MB/s Read 26.3 MB/s
So using a read cache on a class 2 card, makes it read like class 10.
Class 10 only makes base read speed (before cache tweak, faster), but write speed is 4x more.
I have a funny feeling that something else might be limiting my read speed. I will do some research.
It's strange that I've seen other people get 40MB/s on other threads.
I will keep digging, there is much ram that is underutilized for better purposes like this.
If anyone has ideas please let me know. Also if you know where I can change the internal memory read_ahead_cache.
That will boost things by about another 50% if found.
For those who don't mind a good technical read about linux cache:
http://www.kernel.org/doc/ols/2010/ols2010-pages-83-90.pdf