ipod 5.5gen 80gb's test disk result

[isanggon]

I found my 80g's test disk result shows very slow on 512 byte writes are 23 KB/s or less!
Create and delete counts at the top are lower than 30gb.
I wonder this problem is mk8011gah's specific problem or ipod 80g mainboard's common problem.

And another thing,

Can I change this hdd to mk1214gah? Is it work on ipod 80g's mainboard?

[saratoga]

Heres the SVN message when support for the 80GB ipod was added:

"ATA driver: * Support for drives with large physical sectors and no support for partial access in the firmware (i.e. Toshiba MK8010GAH - iPod G5.5/80GB). Sequential writes with a single 512-byte buffer to that disk are really slow, so this is an intermediate solution that allows to adjust the FAT driver and the file system gradually. * Assume multisectors = 16 if the value reported by the drive is invalid (also MK8010GAH)."

[isanggon]

Thank you for quick answer. Then, it's harddrive specific problem.

[dreamlayers]

4096 byte writes are so much faster that they should maybe be used instead.
For example take a look at this test disk result.  (That's the unboosted result without the patch.) 

Suppose a 512 byte write involved reading a 4096 byte block, altering a 512 byte part, and writing back the 4096 byte block.  To keep it simple and pessimistic, let's just use the slowest 4096 byte speed, 2313 KB/s.
(2313 * (512 / 4096)) / 2 = 144.56 KB/s
That's quite an improvement over the fastest 512 byte write speed of 23 KB/s!

The code is already present in firmware/drivers/ata.c.  Look at what MAX_PHYS_SECTOR_SIZE does.  It could maybe use a tweak though, only increasing how many sectors are written at a time because the current 512 byte read speed is similar to 30 gig iPods.

Edit:  On second thought, why not just enable write caching?  You do have a dependable power source:  a battery which the user cannot remove and clean shutdown before the battery gets too low.  All that's needed is a set features command to turn it on, and probably a flush before sleep.

[isanggon]

That's great idea. But sadly, I sold my 80g. It's disk speed was horrible.

[dreamlayers]

Currently is there any way to get a Video iPod with more than 30GB and decent disk speed in Rockbox?  Do any of the higher capacity replacement disks give good performance?

[isanggon]

At least, toshiba mk8025gal works fine with rockbox. I use gigabeat s30 with mk8025gal and disk performance was fine as well as Ipod 30gb's. I think mk8011gah is horrible with rockbox because its abnormal sector size, currently.