yashsingh1/xdaforums huggingface dataset:
[Nook Color Android Development] 360Razir:
Good explanation/write-up, nemith. Not being a dev, but a user, it helps me to better understand which ROMs to use on my NC. I really liked HC EMMC, but did not realize that it would make it so I could never return back to stock (losing my S/N and such).

Also concur with ADude about cache....a good explanation would be helpful here. I only clear the cache/Dalvik when installing a new kernel. Not sure if even necessary? And, I clear AFTER installing, not before, so not sure if I am even doing that in the correct order. Setting the record straight would go a long way for us non-devs.

Sorry, one more thing, it would be great to have a consistently updated bootable SD card with latest/greatest of CWR on it. I am still on 3.0.0.6 and I am not sure why??

Thanks!

~ Razir
[Nook Color Android Development] samuelhalff:
Could have used this a few months ago.

Thank you.

Nemith, your thread is directed at devs. If you want to make sure people don't flash my HC v4 2nd edition, you might want to invite users to read this as well.
[Nook Color Android Development] cromanorn:
I have this installed..... I am going to run the dual boot removal zip when I get home.

Am I screwed? Anthing I need to worry about?:eek:
[Nook Color Android Development] nemith:
I've thought of this. CWM would require a major rewrite to do this and the changes would never be sucked in.

Maybe one of these day's I will may my own CWM Kang that can do this, or better yet a desktop application that takes a update.zip and splits out a SD image!
[Nook Color Android Development] nemith:
No you are just in the "I am smart enough to use these roms without posting big "help me" posts on XDA.

These roms are not really harmful, but they should be avoided by people who don't understand the nook and how it works.

If you understand Android and how the NC is laid out then there should be minimal risk to using these roms. I just want to spell it out for people who are new to the NC or Android that these are "advanced" roms.
[Nook Color Android Development] cromanorn:
THANKS!!! I had the NC for about 4 days now and would hate to have messed it up in the long run. I have a Droid Incredible that has been flashed more times than I can remember. It would be nice if the warnings were incorporated into the OP of these roms. I read the entire thread before flashing and I may not have flashed if this warning was there. I like having the option of going back to Stock without repercussions.

edit: Just saw the update you put in your OP about advanced users. I don't consider myself advanced but I am not a beginner either.
[Nook Color Android Development] 12paq:
Yup. That would be very nice.

The Nook having SD boot priority really makes it versatile for testing, and quite recoverable. It also satisfies a unique situation where many users have a family device with Nook magazines and children's books not available on the Nook app, so many like myself are booting experiments and daily runners from SD and keeping the wife happy. LOL. :rolleyes:
[Nook Color Android Development] nemith:
If you go digging at nookdevs.com and on your own NC you should be able to figure out what is safe and what is not.
[Nook Color Android Development] minotauri:
the ironic thing is CM Roms don't fully follow Rule #3 since they have multiple scripts that run inside their packages during rom installation.
[Nook Color Android Development] jlt220:
I'm not sure you are correct in saying that if you flash one of the HC emmc roms you can not revert back to stock. I know for a fact I have done both the dual boot, and HC emmc roms and reverted back to stock multiple times after doing so

I'm not saying you are wrong but I don't think i did anything to "advanced" to get back.
[Nook Color Android Development] jlt220:
Quoted:

(I have this installed..... I am going to run the dual boot removal zip when I get home.

Am I screwed? Anthing I need to worry about?)

I had it installed and got back to stock no problem... i'm not sure what he is talking about.... i could be wrong though...

It was dualbooted CM7 and HC

went back to stock, registered with BN and all was well.

nooted it and then install HC on emmc

reverted back to stock to set up the ubuntu on NC

got bored of that and am back on HC on emmc
[Nook Color Android Development] actorman46:
I went back to stock after both as well. Has anyone not been able to after using one of those two roms? I work at b&n and I had to spend time with the stock since they wanted me on the nook counter. I've been back and forth between all the roms more times then I can count.
[Nook Color Android Development] jlt220:
To the OP again i'm not trying to be rude, but could you respond to the last few commenter on this thread, it seems like my self a few others are having an experience that is quite different from what you described in your first post.

Could you help me understand why it hasn't been that difficult to get back from the roms that you specifically said can make it very hard to go back to stock from for us?

I'm currently on HM on emmc and if i did something fancy to get back the last time i restores i'd like to know if i need to do it again.

(edit) I bring this back up only because I saw this thread referenced again recently, which means it is having an effect on peoples work so i'm just trying to understand it.
[Nook Color Android Development] Thuneau:
[Edit] It was the SD card's fault. It seemingly worked fine in the laptop and it mounted fine in CW Recovery, but as soon as I used a different SD card I could flash zips again.

So, now I'm playing with phiremod v6 and loving the Nook again.

I believe I just bricked my Nook through use of the dual boot script.

I can only boot from SD into CW but not a single zip can be applied to the internal storage. Not even the "reverse dual boot" zip will run. They all error out.

I believe this is due to unexpected partitioning.

I even formatted boot, system and cache and still it will not restore any Roms.

So now I'm hoping to access the Nook through USB and repartition the internal storage manually. But before I do that, I need to learn about ADB and what the correct settings are.
[Nook Color Android Development] xawen:
I don't think Nemith was saying that the existing dual boot installer is going to prevent you from returning to stock. He singled it out as a "ROM" that modifies the partition table, which can be a dangerous thing to do. There is information stored in the /dev/block/mmcblk0p2 and /dev/block/mmcblk0p3 partitions that is specific to each device and required by the B&N software. This information can't be rebuilt easily if lost.

The dual boot install and removal tools (in their current versions) appear to leave these partitions in tact. They are modifying the partition table though, so they're not recommended for novice users. You were able to install and uninstall it with no problems, so you're clearly not one :).

The other point is that future versions of the dual boot (doubtful since it has a good dev) or other similar style "ROMs" may not be so careful with your 0p2 and 0p3 partitions.
[HD2 Android Q&A, Help & Troubleshooting and Genera] Animefan:
as title, what does it mean ? I saw it pop up in android sd build treads a day or two ago but no idea what it is
[HD2 Android Q&A, Help & Troubleshooting and Genera] uxu:
ClockworkMod Recovery

See here for details > http://xdaforums.com/showthread.php?t=898913
[HD2 Android Q&A, Help & Troubleshooting and Genera] XthelordinatorX:
ClocksWorthMod (sorry if i spell it a bit wrong)

it's used for NAND to very easily update a rom on flash a new rom or do a backup and stuff.

but if you're not into NAND then you don't have to do anything with it ;)
[HD2 Android Q&A, Help & Troubleshooting and Genera] sohaibakram92:
Question since i am new to this stuff!

What does flash mean?.

What does NAND mean?

what are these terms?
[Legend General] Mr.Pigeon:
So I'm running cm7 #32 and I decided to perform a "Wipe Battery Stats" in recovery (followed instructions here: http://wiki.cyanogenmod.com/index.php?title=Troubleshooting#Battery_recalibration). Ever since, my 3G connection has been very flaky .. the 3G and cell signal icons constantly flip between white and green, and signal strength is very jumpy, going suddenly from full bars to no bars. When I do get a full 3G connection, data is VERY slow and mostly unresponsive.

Has anyone experienced this before? I've read a couple of old (non legend) threads describing similar problems after batt wipes, but they don't provided any solutions.
[Legend General] nottechspecd:
I too have the same problem.

I wiped as per the instructions, and my phone actually got stuck at the white boot screen!

I had to pull battery, and reflash cm7.0.2.1 and savagedzen (w/ the no sbc mod, obviously)

Now the phone seems nothing like it used to, buggy, unresponsive, not fun at all. I'm probably gonna nand and reflash.
[EVO 4G Q&A, Help & Troubleshooting] TheEvo:
Does anyone know how to get the MIUI music player on Cm7 RC3? P.S. I've looked everywhere and know this is a repost but none have worked.:confused:
[EVO 4G Q&A, Help & Troubleshooting] teh roxxorz:
http://dl.dropbox.com/u/19699565/com.miui.player-1.apk

Install the apk and it should work fine.
[EVO 4G Q&A, Help & Troubleshooting] TheEvo:
No this the old one I've seen this a million times. I had the new MIUI player but deleted it by accident.
[EVO 4G Q&A, Help & Troubleshooting] teh roxxorz:
Oh....well you can always download the latest rom and the should be able to extract the apk from the app folder.
[Vibrant Android Development] MadJoe:
This is a just a link to brainmaster's thread about this issue. I searched the Vibrant forum and didn't find it anywhere, but it REALLY makes a difference!

Click here to see the original post and download the files you need to flash.

See second post for screen shots of my experience.

This makes my gallery load so much faster it's ridiculous!

Stock I got 11MB/s read speeds, bumping up to the 2048kB gave me 20MB/s, and 3072kB pushed that even further to 29MB/s read speeds.

I am using a 16GB Kingston Class 4 that I picked up from Newegg a couple months ago. Write speeds aren't affected, the difference, I noticed, was whether or not my processor was settled before I started the test. It wasn't on the last two runs, so they have slower writes.
[Vibrant Android Development] MadJoe:
Initial, stock cache:

This was 2048:

And finally 3072:

Sent from my rough sketch of a Vibrant on a brick.
[Vibrant Android Development] bobshute:
I noticed the SD Card speed fix also and ran some tests. This is from my internal SD Card (using my external in my Nook color).

write read

128k Stock

6.6 14.8

512k

6.7 18.7

1024k

8.2 22.9

2048

8.5 36.4

4096k

7.6 32.2

I ran SD Tools five times each, threw out high and low, averaged the other three.

It looks like 2048k is best on the internal SD.
[Vibrant Android Development] MadJoe:
Nice. What SD card are you using, and did you notice any issues with 4084MB? I was going to try it, but 3072 is so much faster, I didn't bother.

Looks like you're running a class 6 or 8 by your write speeds.

edit: I'm confused, is it kB, or MB? I can't remember and gotta get back to work. I'll sort out my posts as soon as I get a chance.

Sent from my rough sketch of a Vibrant on a brick.
[Vibrant Android Development] atoz350:
This is most excellent.
[Vibrant Android Development] bobshute:
This is on the internal SD. I don't have an external installed at the moment.

Edit: What's sick is my Nook Color running CM7 on external SD (Sandisk 8GB Class 4) gets 4.2MBs writes BUT 82.4MBs reads. wish Vibrant could do that!!
[Vibrant Android Development] rorycs:
I think we need to note which SD is being tested, internal or external. On my Vibrant, the only card that SD Tools "sees" is the internal - although I do have the external installed and it is accessible. There appears to be no way to select which card is being tested.

Also, there is an app in the Market (paid) called "SD Speed Boost" which lets you change the cache size immediately using a slider between 128 - 4096 and applies the change immediately without a CWM flash (seems to also have a Set at Boot option, but I have not tried that yet). This makes it a LOT easier to test different settings.
[Vibrant Android Development] atoz350:
I'm using a Transcend Class 6:

4096 hack. I believe it only tests the internal.
[Vibrant Android Development] MadJoe:
What ROM, and/or Kernel are you using? Maybe that's the difference? Nice score, btw!
[Vibrant Android Development] MadJoe:
I've also noticed that my quadrant has gone from an average of about 1950 to now 2050 since flashing this. Anyone know if this hack/mod actually has an affect on Quadrant scores? My Database Reads seem to go much faster now, but it could be a placebo effect ;)
[Vibrant Android Development] kcp877:
I flashed all no change and it only checks my internal sd. I checked the folder etc/initd and the flash did take. Don't understand if there's a criteria for kernel or ext4 enabled for this to work
[Vibrant Android Development] Monk4Life:
Same here using overstocks kernel. No change. Tried it on my HD2 and wow what a difference.
[Vibrant Android Development] atoz350:
I'm using the stock ZSJPJ ROM with the Overstock Kernel. Thanks!

My Quadrant stayed the same.
[Vibrant Android Development] greeneyes513:
Quads went up 100-200. Rebooted still there. Bionix v 1.3.1 OS 2.2
[Vibrant Android Development] kcp877:
Is this only for 2.2.1? That would explain it I'm on 2.2 I didn't see that as a requirement though
[Vibrant Android Development] MadJoe:
I'm using Trigger 2.8.2 and OverStock 2.2, so 2.2 ROMs can see an improvement, but maybe 2.2.1 ROMs just see more significant gains?

Sent from my rough sketch of a Vibrant on a brick.
[Vibrant Android Development] kcp877:
Says on the market page can't test external sd on vibrant
[Vibrant Android Development] rorycs:
Missed that... thanks
[Vibrant Android Development] kcp877:
My result stock kb1 stock kernel with NO voodoo. I can't get better results is this what you guys are getting.

Write 10-11

Write 16.9 almost exact every time
[Vibrant Android Development] Blkegk:
I'd flashed both 2048 and 4096 speed fix and there is no difference between the two. I did see improvements in read speed over stock.

Stock average after 3 test.

Read = 9.5

Write = 5.0

Speed fixed average.

Read = 38.0

Write = 4.8

I currently running the latest trigger rom and overstock kernal.
[Vibrant Android Development] :
It does nothing in my rom, I actually get slower write speeds...256kb is wat I have already in my rom and changing it have me MAYBE +1mb/s read, -3mb/s write
[Vibrant Android Development] atoz350:
After using it for a while I have reverted back to stock.It actually broke my Auto-Rotation. I don't see how it is related, but that was my result. YMMV.
[Vibrant Android Development] kcp877:
Why am I getting 11 for write speeds on stock non voodoo shouldn't it be slower than you guys running voodoo and tweaked roms? I'm on stock deodexed kb1
[Vibrant Android Development] oka1:
My card is write 10.5 and read 17.8 average without the fix, wintec 16 gig class10.......... I ll have to see if it improves (kid plying on the phone now):)
[Vibrant Android Development] nickmcminn60:
WOW! this is on CM7 with the 2080 OC'ed @ 1.3

Write = 12

Read = 122.9

http://www.zumodrive.com/share/bqilZjVkMG
[Vibrant Android Development] BriDroid-74:
Wow, thanks!

Mine went from 7 write/14 read to 8 write/40 read. Gallery loads crazy fast now!

I'm currently running Bionix v 1.3.1 with CW kernel.

BTW my quadrant scores went up about 100 or so to just over 1500.
[Vibrant Android Development] Mattymat:
On simply honey with overstock 2.2 and I haven't noticed any increase in any benchmark. That's after I flashed every single new script. Maybe the others are right and 2.2.1 roms running the overstock kernel see no increase in performance.

Sent from my mobile
[Vibrant Android Development] plane501:
13mb+ write

120mb+ read

cm7 3076k
[Vibrant Android Development] PJcastaldo:
On sweet honey 2.7.2 w/ overstock 2.2 oc at 1.2, noticed a write increase of about 3.5 bringing it to 6.8/s but not really a change in reads. I used sd tools to test. But no change in quad scores.
[Vibrant Android Development] zimphishmonger:
Just decided to copy data off my internal SD to my PC as a test, as Im quite familiar with the typical transfer speed. Using 2048kb, my transfer speed increased from ~5MB/s to almost 10-11MB/s....:D
[Vibrant Android Development] VVerevvolf:
I chose the 3072 fix after testing them all with SD Test. I noticed my read and write scores improved and my quadrant hit 1800 for the first time!

See sig for ROM/Kernel.
[Vibrant Android Development] kponti:
Ok as we all know there are two SD cards on this phone....so how does this work? Which SD card are we increasing speeds to if we do this mod?

The internal or external?

How do we do them both?

Sd Tools seems to only test internal SD cards so is that the only one we can check?
[Vibrant Android Development] w_bovine:
That is somewhat confounding in that I can only test the external SD on my Vibrant. Unless the app is reading my internal SD at 8GB.

I have not seen any improvement in read speed running ZSJPJ Stock Tweaked from jellette with that ROM's standard kernel. 8 GB class 6...it's an ADATA I think.
[Vibrant Android Development] Wade-0:
So what is the downside to bumping the read_ahead cache? I have to assume that it was set low for a reason. Why wouldn't the majority of custom ROMs be doing this already if it's so easy?
[Vibrant Android Development] MadJoe:
That's a valid question; I don't know. I ask myself every day, why did Samsung make this stat-stacked phone and kneecap it with the RFS file system? So now I get to ask myself: why did they also kneecap the sd card?!?

Maybe to make modding it that much more rewarding?

Sent from my rough sketch of a Vibrant on a brick.
[Vibrant Android Development] nickmcminn60:
Cant help but wonder if this is just tricking the test resulting in bloated numbers. (kinda like ext2 did to quadrant) Big numbers but no real-life gain? I scored 122.9 on READ: http://www.zumodrive.com/share/bqilZjVkMG
[Vibrant Android Development] Wade-0:
It's one thing to question Samsung's choices, it's another thing entirely to question all of the aftermarket ROM developers. What reasons might they have for not incorporating this tweak in their ROMs already? Or are you suggesting that they are ALL completely ignorant of this setting?
[Vibrant Android Development] tissimo:
Increasing cache size, so not actually reading off the sdcard, but rather the ram.. Real world you'll have a slight increase if the app/os prefetches the data into the cache.
[Vibrant Android Development] :
I get ~7-12mbs write, ~18-22mbs read stock TOXIC 1.0 with overstock2.2 kernel and my usual 256k read ahead, doesn't change much if any with any of the other sizes. My gallery loads faster with the 256k than anything else, Id like to ask how many runs are people doing before they average? And the more you run the test the faster speed u get (at least on mine). From my testing I see little difference above 256k.
[Vibrant Android Development] nickmcminn60:
Ran it about ten times and yes it did seem to steadily improve untill about the 7th run. Then it started coming down with each additional run so I stopped.

I was only getting like 7 write and 15 read ( stock) and 12 write and 100+ read with the 256k
[Vibrant Android Development] :
mine shot up around run 4 or 5, thats when I started to doubt the test app. The SD card speed apps really arent accurate enough, just go with W.E feels best to you you guys. 256k works best for me, if you think you feel a speed improvement, keep it, hell try 6144 or 8193 for funzies! Our SD speeds really arent that slow to begin with, if it was ridiculous thatd be one thing, but I've had no problems with SD speed in the past 9 months, even on stock it reads it more than fast enough =3
[Vibrant Android Development] BruceElliott:
Not exactly. In the case of the quadrant test with ext2, quadrant was attempting to test the I/O speed by writing files and then reading them back. The problem was that the files were being written to and read from RAM rather than being written to and read from flash memory.

Here we are talking about a read lookahead cache. So, for starters, the current exercise has absolutely nothing to do with write speeds. As either the test or real-world applications read files, the look-ahead cache mechanism attempts to anticipate the next [cache size mb] of files that will be requested. If the cache mechanism guesses correctly (called a "cache hit"), then when the application gets around to reading files that happen to be in the cache, it can read those files at RAM read speed rather than at flash read speed. In the case of results being reported of faster Gallery speeds, for example, the cache mechanism is smart enough to know that when you open Gallery you will probably be opening image files. So, the cache mechanism reads some image files from flash and puts them into the RAM lookahead cache before you actually press the file icon to open that particular file.

So, hopefully from this you can see that the quadrant/EXT2 case was a test write then read back. In the case of an SD card read test, at least some of the data being read by the test is being accessed from the read ahead cache rather than from SD card memory. By increasing the size of the read cache, what we are really doing is increasing the statistical probability that the file that we next require will already be in RAM when we need it. It might appear at first glance that this increase in reading efficiency might scale up to ever larger cache sizes, however that is not the case at least because (a) a point may be reached at which an application is, for all practical purposes, accessing the data it needs at RAM speeds, and you cannot go faster than that; and (2) there is an amount of time overhead associated with operating the cache algorithm. That overhead increases with increasing cache sizes.
[Vibrant Android Development] BruceElliott:
Originally Posted by nickmcminn60

Ran it about ten times and yes it did seem to steadily improve untill about the 7th run. Then it started coming down with each additional run so I stopped.

I was only getting like 7 write and 15 read ( stock) and 12 write and 100+ read with the 256k

Of course read test speeds will increase each time you perform the test, up to a certain number of test iterations. That is because the cache algorithm increasingly populates the cache with more relevant read ahead data with each iteration.

The moral of this story is that a test is meaningless unless it is performed immediately following a reboot. Or, said differently, you must re-boot, test once; re-boot, test once; etc.

Edit: BTW, the latter is true of Quadrant in general. You must reboot between tests to avoid the "cache learning" phenomenon if you expect accurate results. I suspect that much of the disparagement directed toward these various tests is a consequence of operator error.
[Vibrant Android Development] kponti:
Well certainly helped my gallery load faster, but then again I only had 4kb cache set with the Bionix 1.3.1 rom
[Vibrant Android Development] MadJoe:
Nice (failed) attempt to stir up drama.

Sent from my rough sketch of a Vibrant on a brick.
[Vibrant Android Development] :
I ran it 3 times and rebooted, then did the same several other time with no significant change with any of the "fixes". I understand how the test works. Just wanted to point that out =) that I only did the many consecutive runs after doing the reboot runs testing the other "fixes" to see if the results changed then, but they still didnt =3
[Vibrant Android Development] :
lol, failed forum drama attempt XP
[Vibrant Android Development] Wade-0:
Nice attitude, sheep. "They said it makes it fast, I'll just believe whatever I read on random postings on internet forums!"

At least BruceElliott has attempted to introduce some useful information on this thread, the rest is just FUD. :rolleyes:
[Vibrant Android Development] nickmcminn60:
Very well written. And thanks for the explanation.