Database Develop

Storage Card Woes(A Public Service Announcement)

People have been reporting problems with corruption and losing files on memory cards, particularly 2GB ones.
I am having the same problem with a PQI 2GB bought from Fry's(PLU# 5044075 and P/N: AE62-2030R01F4) in Houston, TX.
When I try to download something from an FTP Client to the storage card, it fails and when I leave stuff on it, it becomes corrupt and stuff disappears. Also, when transferring files over FTP, it moves at about 5-8 KBps.
I took my roommate's 64MB PQI from his Sidekick III and it worked like a charm. It was as follows.
1 Head
1 Cylinder
Type: FAT12
Sector: 512 Bytes
Cluster Size: 16 KB
BackupFAT: Yes
I used Pocket Mechanic(amazing interface) and Resco which is great and clean as well! Thank you for the recommendation. I scanned my card for bad sectors and they were all good.
This morning I used my co-workers SanDisk 1GB card and downloaded files from my FTP at 22KBps over EDGE which blew my mind. Furthermore, they weren't corrupted. His file system was FAT32.
My conclusion is that it isn't the formatting options, but the PQI cards and the old motto of "You get what you pay for". I am going to have to break down and buy another card which I really didn't want to do, but it's obvious that SanDisk clearly holds it's weight in these devices.
Thanks to everyone who made recommendations and turned me on to some great apps in the process. I'll update this when I get my new card and let you guys know how it went. Thanks again for being a great community!
EDIT: Could people without problems with a 2GB Post the following info to help those trying to buy a card?
Brand:
Part No:
Format Method
Type:
Sector:
Cluster Size:

Flash memory doesn't have heads or cylinders

I know, but the stat was there so I included it in case someone got a different value reported back to them...

soopahfly said:
Flash memory doesn't have heads or cylinders
Click to expand...
Click to collapse
Correct, but there may still be logical heads and cylinders for backwords compatibility with some OSes or software.
I dont know about the case with SD cards, but CF cards can be directly connected to an IDE bus and emulate an HD.

MMC Plus and SD 4Gb - slow write speed

Here is a problem... I've tested 4Gb SD card's FAT16 write speed using XDA IIi. And it is 2 times slower than one on 2Gb SD card(both Transcend, 150x). Nearly 630kb/s(2Gb) and 375kb/s(4Gb).
So, speed is unacceptable.
Will 4Gb MMC solve this speed problem?

Hi
You need to reformat you SD4Gb in Fat32. I had same problem like you with MMC+ 4Go and SD 4Go 150x, both from transcend. I reformated in FAT32 and they are more quicker.
Try it and ket me know.
You can use Pocket Mechanic from Anton Tomov which is a very good software.
Cheers

Hmm... Same benchmark gives me even slower result with FAT32... What cluster size are you using?
Best results achived with FAT16 64Kb cluster... Using SKTools for benchmarking.

Sectors per cluster:64
Bytes per sector: 512
Cluster Size is 64x512 = 32768
Hope it helps

SD Card

Could anybody tell me, why my new SD Card (Panasonic 2 GB Class 6) is much slower on my Alpine than my old SD Card (Panasonic 2 GB Class 2)? Here are the results from the SK Tools benchmark :
Class 2 Card: Read 6187 kb. Write 636 kb.
Class 6 Card: Read 729 kb. Write 481 kb.
Isn't it funny?
Perhaps I should format the SD Card properly?
Any ideas?
Thank you.

are cards empty when you check write speed?
class tells about writing speed on complitely empty cards

I tried both benchmarks, with the empty and the full card. The class 2 is much faster, especially in the write result. Unfortunally I formatted the new card on my device, with the effect that the card was become more slower. After that I formatted the card on my computer, now it's better, but nevertheless slower than the old one.

maybe it's something wrong with the card
the 2nd one is almost 10 times slower readed :/
did you check speeds on PC?
maybe PPC just can't handle with faster card

deezer said:
maybe it's something wrong with the card
the 2nd one is almost 10 times slower readed :/
did you check speeds on PC?
maybe PPC just can't handle with faster card
Click to expand...
Click to collapse
Well, that's my question. Where can I get the adequate information? How can I check the speeds?

use this
http://www.simplisoftware.com/Public/index.php?request=HdTach

Now I've found out that SD/SDHC Memory Card file systems formatted with generic operating system formatting software do not comply with the SD Memory Card specification. You need a special formatting program that complies with the SD Memory Card specification.
Because I have a Panasonic card, I took the Panasonic free SW (
link: http://panasonic.jp/support/global/cs/sd/download/sd_formatter.html).
The benchmark results are: Nearly 14000 KB/s (read), but still 470 KB/s (write) only.
No idea, how to increase the write performance.

[Q] SD card Cashe size

Hello all
The following post are on the frontpage of XDA today.
forum.xda-developers.com/showthread.php?t=1010807
The hack is ment to increase the cashe size used for SD card reading and thus increase the overall performance of the phone (when it reads from the SD).
I noticed that this hack only affect the internal SD card on the Galaxy S phone and that the results aint that great as reported in the original post. I wonder if any one can make this hack for the external SD card, so we can test the effect. we might just have to change the value at
/sys/devices/virtual/bdi/179:8/read_ahead_kb
but I dont know how to test it since SD Tools seems to pick the internal at all time.
NOTICE: since this should only affect the read speed, I would ignore the results of the write speed (it might have some kind of effect, but I simply dont know).
Bias: It is also a fact that SD Tools seems to give different results if you run the tests continously (with the same amount of cashe) without closing SD Tools down, compared to Running one test, kill SD Tools, run a new test.
Tests
The avg score is what I think it is after looking at the test. It is not any number reported, since the score reported by SD tools is just the last read/write speed. I also ignore the vary high number at the start of the test, since it seems like an outlier.
128 kb cashe:
Write: Interval = [5 mb/s ; 40 MB/s]
Avg = 11 MB/s
Read: Interval = [8 mb/s ; 18 MB/s]
Avg = 11.4 MB/s
1024 kb cashe:
Write: Interval = [3.8 mb/s ; 20 MB/s]
Avg = 5 MB/s
Read: Interval = [15 mb/s ; 19 MB/s]
Avg = 18 MB/s
2048 kb cashe:
Write: Interval = [11 mb/s ; 40 MB/s]
Avg = 25 MB/s
Read: Interval = [15 mb/s ; 22 MB/s]
Avg = 17 MB/s
3074 kb cashe:
Write: Interval = [4 mb/s ; 20.5 MB/s]
Avg = 5 MB/s
Read: Interval = [10 mb/s ; 40 MB/s]
Avg = 20 MB/s
As you can see, the write speed on 2048 kb seems all wrong, but as said before, I ignore the write speed.
From this test, it seems like 1024 kb is just fine.
Feel free to comment and post your results.

old trick, i edit it manually

But how do you change the cache size for the external SD card?
This hack is only for the internal

external SD
edit
/sys/devices/virtual/bdi/179:0/read_ahead_kb
and change the size to whatever you want

[Q] writing speed memory low

i have aproblem, my phone became recently a bit slow while downloading(torrents), i couldnt watch a yt vid(because it wpuldnt buffer, its not my internet connection that is bad and torrent didnt even took half of my bandtwith) so i did a benchmark, with some disturbing results:
sequential writing speeds: 3.74 mb/s
random writing speeds: 0.16 mb/s 42.01 iops(4k),
these benchmarks were done by androbench, they gave a ttop 10 list where there is a device with the same soc with over 15k iops random write speeds.
can this problem be solved with software or is the memory chip broken? Will a custom rom help?