Related
How much does class speed matter for a smart phone. I was under the impression that it's mainly important for video capture and photography (when using a digital camera).
Sent from my DROID2 GLOBAL using XDA App
There is no requirement or restriction on this. Anything microSD or microSD HC will work. Recommended is to get class 2 or better card in order to achieve better speeds when copying stuff from/to phone via USB in disk drive mode.
However under 'anything' do not assume you should go and get the cheapest ever card you find on eBay or something - if card isn't functioning good, phone may experience wired behaviour like resets/etc. Get something recognizable (SanDisk, Kingston, etc).
Some video camcorders require certain class+ card in order to keep up with HD recording bandwidth required. Since D2G can't even shoot 720p, even slowest card will be ok. Not that 720p would have required more...
leobg said:
There is no requirement or restriction on this....
Click to expand...
Click to collapse
Leo are you certain it will take ClassIII memory? It makes sense just not sure the hardware did that.
to the OQ - If they come out with a newer class there might be a compatibility issue with the phone but XDA folks usually finds away to support them soon after via a patch.
Stay away from old legacy (Not Classed) SD cards. Go for the fastest and largest you can afford.
Android rely's much more on the SDcard than WM ever did.
the phone should support up to class 6 (or whatever is the highest class) just fine, class just means the speed of the card, the d2g supports any class micro sd card up to 32gb in size, so as long as you dont exceed that, youre fine. the speed of the card could be a factor for programs that cache to your sd card, youd want a faster sd card if you plan to have programs do that.
I am pretty sure the class is backwards compatible. Kinda like USB 2.0 and 1.0. Its going to use the fastest the device is capable of using. I think it's more the size limits (In the case of android, 32gb) that matters. Granted, I could be mistaken.
does anyone know the max sd card transfer speed of the pad, and the dock?
i am looking at a 128GB SDXC card (yes, its a lot, but this is replacing a dead laptop for the foreseeable future) , UHS-1 60mb/s, or a 45mb/s one. will the UHS card actually have any benefits in the dock, or simply when transfering data to it from the PC.
many thanks!
I'm currently running a Class 10 (200x) 32 GB SDHC in the dock, branded Dane-Elec. Runs fine. I don't know if it takes 32+ GB cards, though... And to be honest, while heavily dependent on what you actually do with it, for most purposes a high-speed card should suffice...
ishamm said:
does anyone know the max sd card transfer speed of the pad, and the dock?
i am looking at a 128GB SDXC card (yes, its a lot, but this is replacing a dead laptop for the foreseeable future) , UHS-1 60mb/s, or a 45mb/s one. will the UHS card actually have any benefits in the dock, or simply when transfering data to it from the PC.
many thanks!
Click to expand...
Click to collapse
I'm currently using two Sandisk cards:
- microSD class 10 30MBps SDHC Ultra (16GB)
- full SD class 10 SDHC Extreme 45MBps in the docking station (32GB)
They get better speeds than the built-in disk, but it is still not great. It seems to be about 15-18Mbps write for SD, 6Mbps write for microSD and 30-32Mbps read for both (as compared to 12/18 of the internal memory).
The fastest way of moving data still seems to be external USB HDD...
Hope this helps, haven't tried any other yet. I have tried both FAT32 and NTFS though. They seem to give similar results (I had no problems using NTFS on my SD card so far, which is a good sign).
d14b0ll0s said:
I'm currently using two Sandisk cards:
- microSD class 10 30MBps SDHC Ultra (16GB)
- full SD class 10 SDHC Extreme 45MBps in the docking station (32GB)
They get better speeds than the built-in disk, but it is still not great. It seems to be about 15-18Mbps write for SD, 6Mbps write for microSD and 30-32Mbps read for both (as compared to 12/18 of the internal memory).
The fastest way of moving data still seems to be external USB HDD...
Hope this helps, haven't tried any other yet. I have tried both FAT32 and NTFS though. They seem to give similar results (I had no problems using NTFS on my SD card so far, which is a good sign).
Click to expand...
Click to collapse
I haven't used an external drive yet, but I agree with the observation that the transfer speed is not optimal, no matter what card I plug in (I have transplanted a few I normally use in my DSLR just for testing; they are all fast cards, as you can imagine). I transferred several documentaries and a lot of photographs yesterday evening and it took ages, mainly due to the fact that the transfer process hangs up the entire device (!) regularly. It seems to happen after about 70 to 80 MB are read into (temporary?) memory and apparently are only then buffered out to the main storage. Let's hope a custom ROM can straighten this issue out...
Thanks. Given these figures, would you install apps on the main memory, if a 30mbps rated micro sd for best performance?
Sent from my LT26i using xda premium
ishamm said:
Thanks. Given these figures, would you install apps on the main memory, if a 30mbps rated micro sd for best performance?
Sent from my LT26i using xda premium
Click to expand...
Click to collapse
In my case internal memory is faster than microSD. You don't really have the option, unless you play with the filesystem and mount your MicroSD on /mnt/sdcard instead of /Removable/MicroSD. In the Infinity /mnt/sdcard is just a folder within the internal memory by default (many apps use it though, so they had to arrange it this way). I don't think there is any reason to change this, as internal memory seems faster and that's whole 64GB of it (OK, maybe 56 available, but still a lot..).
Perfect thanks, I thought though that there were current issues with I/O speeds until someone could fix it in a Rom. Or has this been addressed in the new firmware?
Sent from my LT26i using xda premium
ishamm said:
Perfect thanks, I thought though that there were current issues with I/O speeds until someone could fix it in a Rom. Or has this been addressed in the new firmware?
Click to expand...
Click to collapse
Hopefully I could tell you in a few days, but honestly I don't think it has (can't try it out yet, as the firmware released is Taiwanese version, and I'm on the World-Wide).
The Infinity is not that far behind other new tablets or rather it's not only TF700's problem, see http://forum.xda-developers.com/showpost.php?p=28416635&postcount=2842
However, after changing the scheduler to sio and doing some tweaks (see my post on it: http://forum.xda-developers.com/showthread.php?t=1758160), it's running pretty smoothly (unless you want to do a lot of CPU-heavy jobs while having huge reads or writes in the background, in this case it can get frustrating, but.. there is no real alternative these days).
d14b0ll0s said:
Hopefully I could tell you in a few days, but honestly I don't think it has (can't try it out yet, as the firmware released is Taiwanese version, and I'm on the World-Wide).
The Infinity is not that far behind other new tablets or rather it's not only TF700's problem, see http://forum.xda-developers.com/showpost.php?p=28416635&postcount=2842
However, after changing the scheduler to sio and doing some tweaks (see my post on it: http://forum.xda-developers.com/showthread.php?t=1758160), it's running pretty smoothly (unless you want to do a lot of CPU-heavy jobs while having huge reads or writes in the background, in this case it can get frustrating, but.. there is no real alternative these days).
Click to expand...
Click to collapse
This. As i've ranted earlier, the new firmware provides fixes for camera issues, not for the I/O the TF700 so obviously suffers from. Having said that, it is not like the tablet in itself is useless as it is -- far from it -- but remains a mystery to me why they didn't spot this in advance (like with the Prime's issues with GPS and wifi), It seems like ASUS develops a device by letting several teams work onindividual components, and, when they get their specific part up and running, just put it together and relese it. I have a distinct feeling that neither device was actually and properly tested.
But, still, I'm pretty happy with the device overall.
I think you need to read this thread:
http://forum.xda-developers.com/showthread.php?t=1767755
From what I see my UHS-1 card that doesn't work is initialized as DDR which means the max speed for the TF700T µSD is 50 MB/s (as that is the only DDR speed).
The full size SD socket uses a USB host so the big question is is it USB 2.0 or 3.0!
All specifications says USB 2.0 for the dock, so I would assume that's correct, even for the TF700 dock.
Asus has finally responded that there is limited UHS-1 support in the µSD slot.
For now you are better off not trying UHS-1 in there. The may come up with a patch...
external memory limits
ishamm said:
does anyone know the max sd card transfer speed of the pad, and the dock?
i am looking at a 128GB SDXC card (yes, its a lot, but this is replacing a dead laptop for the foreseeable future) , UHS-1 60mb/s, or a 45mb/s one. will the UHS card actually have any benefits in the dock, or simply when transfering data to it from the PC.
many thanks!
Click to expand...
Click to collapse
Careful there with a 128gig card, I read somewhere that there is a 32 gig upperlimit on recognizing cards and sticks...
tho I do wonder if you formatted it into enough partitions it might read them all?
kokoPedli said:
Careful there with a 128gig card, I read somewhere that there is a 32 gig upperlimit on recognizing cards and sticks...
tho I do wonder if you formatted it into enough partitions it might read them all?
Click to expand...
Click to collapse
If the dock uses a sdhc compatible controller and simply exposes the card as a mass storage device for the system, then there is really no such limit. The SDXC cards which supports >32GB does so due to the SD's FAT specification not for actual addressing and such.
SDXC cards are accessible as SDHC but standard specifies ExFat as default filesystem. This may not work on units not compatible with ExFat, but a reformat will fix that. In the TF700T's case we have already seen users use 64 GB cards breaking that 32GB barrier.
We have also seen the TF700T mount ExFat, although it seems to fallback to NTFS.
The thing he should be carefull of is UHS in the µSD socket as it's still wonky.
In the dock I suspect a UHS card will simply be treated as a normal SDHC card, but UHS cards usually have better class speeds so may be a benefit even with the dock doing USB2.0 hosting.
Edit:
To back up my claims see here...
http://kb.sandisk.com/app/answers/detail/a_id/2520/~/sd/sdhc/sdxc-specifications-and-compatibility
I have a new TF700T with the Keyboard/Dock, and am wanting to pretty much max out its storage capacity in preparation for an upcoming trip (photography).
I realize that the Tablet itself requires MicroSD. I'm actually looking at this one:
Sandisk 64gb MicroSDXC Class 10
The Dock will obviously take a straight SD card, or a MicroSD card using the SD adapter. Is one of these ways any better as far as performance and reliability? I want to maximize read/write speeds.
I've also read enough threads here and elsewhere to see that this device is finicky with regard to which cards it'll work with, which formatting will be accepted and seen, etc. Any thoughts/experience in terms of which 64gb SD and/or MicroSD work best would be appreciated. And I understand that the higher the Class, theoretically the faster read/write speeds, but in an imperfect world, this isn't always the case, especially with this somewhat quirky device.
DLCPhoto said:
I have a new TF700T with the Keyboard/Dock, and am wanting to pretty much max out its storage capacity in preparation for an upcoming trip (photography).
I realize that the Tablet itself requires MicroSD. I'm actually looking at this one:
Sandisk 64gb MicroSDXC Class 10
The Dock will obviously take a straight SD card, or a MicroSD card using the SD adapter. Is one of these ways any better as far as performance and reliability? I want to maximize read/write speeds.
I've also read enough threads here and elsewhere to see that this device is finicky with regard to which cards it'll work with, which formatting will be accepted and seen, etc. Any thoughts/experience in terms of which 64gb SD and/or MicroSD work best would be appreciated. And I understand that the higher the Class, theoretically the faster read/write speeds, but in an imperfect world, this isn't always the case, especially with this somewhat quirky device.
Click to expand...
Click to collapse
I have one of those, formatted with exFAT. In the tablet it seems fine, and I can put video files on it and stream them off with no problem.
Not tried it in the dock.
If I unmount it clean from the tablet it is usually fine in my Windows 7 laptop; but occasionally it gets left in a dirty state and Windows will mount it read-only. I don't know if that's common with other cards.
However, in another thread I started a while ago I think we've found that the card can't be used in the tablet for recovery purposes. That may or may not matter to you.
Thanks for the reply. I went ahead and order the MicroSDXC card above, along with the full SD version of the same Class 10 card. I heard from another TF700T user for whom the MicroSDXC worked fine, so hopefully I'll be okay.
And thanks for the tip, but no, I won't need that card for recovery purposes.
Best,
I bought this SD card from amazon
Sandisk Ultra 32GB Class 10 Micro SD Card with SD Adapter
http://www.amazon.co.uk/gp/product/B007JTKLEK/ref=noref?ie=UTF8&psc=1&s=computers
formated by 4ext, has 1 EXT4 with 1GB/512MB, rest are FAT32. Installed VJ CM10.1 5.1 ROM, a2sd YNY. Nightmare came after phone booted, it's fast, but randomly "DEAD". "DEAD" mean phone totally freezed, no response at all, include all keys and screen. Have to remove the battery to restart....
I changed back to my old Class4 sd card. Did some test on this new class10 SD card, has no problem at all.
Is it because it's 32GB? Should I use a 8GB instead? Please help.
Hello!
I'm not sure, but i read alot about people getting trouble with a 32gb SD. Maybe do the partition again, something might have gone wrong.
Hope it helps,
- Rinse
Hello,
The first partition must be FAT32, than you can create the second partition in EXT4 format, I think.
Insert in pc, restore to defaults, format, then do as you please!
Huh, strange - I have same card, but 16GB.
In my tablet it is working without a problem. But in desire - I was trying for 5 days to make it working - without luck Random freezes, FC, phone dead (had to remove battery to power it on).
I tried diffrent roms - didn't work. Tried to format it (in 4ext), zero it (on pc with card reader), partition it again with diffrrent partition sizes (1.5GB, 1GB, 512MB) - nope.
Card is ok (as I said - in tablet it's working) - but my desire don't like it So I'm still on 2GB class -500 and thinking what to buy (8GB class 10 ? what manufacturer - adata, kingston? )
is 32gb working on htc desire?
SanDisk cards are known to cause the problems you described with the HTC Desire. I had a SanDisk 8 GB card too, and exactly the same problems... the solution is to not use SanDisk cards.
xhemx said:
is 32gb working on htc desire?
Click to expand...
Click to collapse
No it ain't...... My Desire lags as hell when I use the 32 GB class 10 Kingston card... Works on my QMobile Q3i.... Dunno how...
are you sure UHS-1 cards like these sandisk ultra are compatible with desire ?
Hi,
I'm using a sandisk card too, i do have a lot of problems with my HTC Desire.. can't use the phone anymore for daily use.
Freeze by phone calls, have to reboot 3 times before it's good and well started up.
Maybe SanDisk is the problem? Can someone confirm this? But why do they liver SanDisk by buying the phone then?
I have Samsung class 10 card and it works realy good.
Sent from my HTC Desire using xda app-developers app
Me too, using a Samsung class 10 16gb for a long time with int2ext and it really works fast and stable.
henrikht said:
I have Samsung class 10 card and it works realy good.
Sent from my HTC Desire using xda app-developers app
Click to expand...
Click to collapse
Hi there,
I have the same problems with SanDisk 4GB class 6. The trick is do not use app2sd.
I want also know if other cards like kingston do have the same problem.
Now i'm using VJ 4.1.2 with sd-card fat32 and no apps installed. At this moment there are no problems with my phone.!
squarefw said:
I bought this SD card from amazon
Sandisk Ultra 32GB Class 10 Micro SD Card with SD Adapter
http://www.amazon.co.uk/gp/product/B007JTKLEK/ref=noref?ie=UTF8&psc=1&s=computers
formated by 4ext, has 1 EXT4 with 1GB/512MB, rest are FAT32. Installed VJ CM10.1 5.1 ROM, a2sd YNY. Nightmare came after phone booted, it's fast, but randomly "DEAD". "DEAD" mean phone totally freezed, no response at all, include all keys and screen. Have to remove the battery to restart....
I changed back to my old Class4 sd card. Did some test on this new class10 SD card, has no problem at all.
Is it because it's 32GB? Should I use a 8GB instead? Please help.
Click to expand...
Click to collapse
I have the same card I picked up last fall and have the same problem. I'm going to try it out in a DSLR to see if it works there. My old card is a class 8 Adata (I think, might be Kingston) and started to randomly corrupt the fat partition, loosing all data and requiring a full reformat (which is why I got the Sandisk in the first place). So I can use a card that makes my phone completely useless as a phone or use a card that randomly looses all of my data. I should probably get a new card. On the upside I have become prolific at backing up my data. Also worth noting is that the Sandisk card is fast while it's runing.
I'm using SanDisk ultra 16gb uhs-1 for a couple of months now, didn't have any such trouble. could pvt version of desire be connected with that? Mine is pvt3
I'm also pvt3. I'm also rooted, s-off, use a2sd, no change with mounts2sd, and tried different ROMs (ICS, JB 4.1 & 4.2).
It seemed to only happen while using a heavy app if the phone was bogged down with multiple apps. To rule out a power supply voltage drop I replaced the battery. Although replacing my two year old battery was a good upgrade, it did not fix
the issue.
Everything I've tried points to a SD card issue so it is interesting to hear that it may only effect the 32GB UHS-1 cards. Samsung isn't as readily available around here so I may try the 16GB version but I'd prefer the upgrade to 32GB capacity. The card was phenomenally fast while the phone remained stable so I'd take speed over capacity. I just haven't seen mention of this problem with other 32GB cards.
Sent from my HTC Desire
If partitioning with 4ext recovery and cleaning the sd port in your phone (blow some compressed air into it, with phone powered off and let it regain normal temperature before powering back on) won't help, try sending the card back to SanDisk, in my country they give lifetime warranty for their cards. But first you gotta make sure your desire is intact hardware wise.
You might also test your card with tools like crystal disk mark and see if it gives up when strained.
follow topics....
Criise said:
Hi there,
I have the same problems with SanDisk 4GB class 6. The trick is do not use app2sd.
I want also know if other cards like kingston do have the same problem.
Now i'm using VJ 4.1.2 with sd-card fat32 and no apps installed. At this moment there are no problems with my phone.!
Click to expand...
Click to collapse
Exactly that was my experience.
I got the SanDisk (Class 2, 4GB) which came along with the HTC Desire and bought a new SanDisk for mobile devices a few months ago (Class 6, 8GB). Both are working fine if I don't partitoning the cards/don't use A2SD - the phone won't freeze, etc.
If I partition these cards (method doesn't matter, tried CWM, GParted and another tool [don't know the name]) the phone is going to freeze randomly and on 2G network every time. My HTC Desire is PVT1. I rooted and flashed two PVT3 and one PVT4 devices as well and aligned their cards - no problems at all. No freezes, everything is running pretty good. So I have no idea.
The last months my phone barely run, it was freezing all the time. Even some ROMs which were running very great 2 years ago didn't run again (My boyfrriend said the problems occured because I was flashing it too often... But I can't believe that ).
I wasn't able to figure out what's wrong, so I decided to buy a HTC One.
I guess it's some hardware related issue?
squarefw said:
I bought this SD card from amazon
Sandisk Ultra 32GB Class 10 Micro SD Card with SD Adapter
http://www.amazon.co.uk/gp/product/B007JTKLEK/ref=noref?ie=UTF8&psc=1&s=computers
formated by 4ext, has 1 EXT4 with 1GB/512MB, rest are FAT32. Installed VJ CM10.1 5.1 ROM, a2sd YNY. Nightmare came after phone booted, it's fast, but randomly "DEAD". "DEAD" mean phone totally freezed, no response at all, include all keys and screen. Have to remove the battery to restart....
I changed back to my old Class4 sd card. Did some test on this new class10 SD card, has no problem at all.
Is it because it's 32GB? Should I use a 8GB instead? Please help.
Click to expand...
Click to collapse
Try following the steps HERE, make sure your partition is no bigger than 1.5 GB (I read somewhere it can cause issuess otherwise, I can't find it now though). I hope this helps!
Hi.
i've been using my samsung galaxy tab 2 7.0 (GT 3110) with stock JB 4.1.1, rooted and running Smanager with "internal2externalsd swap" script.
it had been working fine for 1 week, yesterday i was playing alien vs predator which i didn''t like and erased it. i go to sleep, wake up, and now the tablet says the microSd is damaged, but does not let me format, neither in my laptop (it does detect it, but when trying to format it tells me to insert the microsd).
it is a MicroSD 32gb class 4. (apparently no one brings class 10 to mexico).
This is the 2nd MicroSD i screw (yet the previous to this one, which was replaced by warranty, there was an obvious cause, because i did something wrong and the tablet stucked and it would auto reboot many times so the microSD was under lots of pressure, and besides i had the memory swap script running alog with "Link2SD" app so it was like a constant battle between them i guess)
anyway...
i do not want to screw another one as i doubt they would replace this with another one as obviously my tablet is the problem.
could it be the script?
could it be the fact that i use to force stop some apps?
could it be that i deleted some stock samsung apps like the game center and that stuff?
there was really nothing to suggest a malfunction :S, and i've used temporarily the microSD of my cellphone (8gb class2) and no problemwith that one :S (used it 2 weeks while waiting for the replacement of the first one, in those 2 weeks i formatted the tablet, started clean and had only the script running, no problem at all)
what do you guys think and suggest?
Every time i read those threads, i think that samsung has anything include in this tab, that destroyd every sd card, that is not from samsung.
Its not the script, its the tab, it doesent like non samsung sd card's
Gesendet von meinem MK16i mit Tapatalk 2
really? damn.
i tried to find similar threads but no luck :S.
it will be hard to find a samsung microSD here in mexico =(.
is it really my only option? no way to prevent this? i can't find any info anywhere =(.
Dexxmor said:
Every time i read those threads, i think that samsung has anything include in this tab, that destroyd every sd card, that is not from samsung.
Its not the script, its the tab, it doesent like non samsung sd card's
Gesendet von meinem MK16i mit Tapatalk 2
Click to expand...
Click to collapse
You're really suggesting this? I highly doubt this is the problem. I've been running a non-Samsung SD since the beginning. The problem is with the script. Try running a higher class SD or stop running the script.
RikRong said:
You're really suggesting this? I highly doubt this is the problem. I've been running a non-Samsung SD since the beginning. The problem is with the script. Try running a higher class SD or stop running the script.
Click to expand...
Click to collapse
The problem is the microSD card.
You don't need a higher class microSD card to effectively utilise the swap script. Neither does the swap script directly damage the card.
What happened here is likely a poor quality or defective card that could not handle the increased R/W when using the swap script.
Some may argue that there is increased wear & tear on the microSD card when using the script, but the microSD card, regardless of class, would last a long time before failing.
There have been many reports of Sandisk cards failing in Samsung devices. Sandisk has already acknowledged defective batches of cards. Go google to learn the specifics.
It was a Kignston 32GB Class 4.
i am planning on getting an AData 32GB class 10. (the only class 10 i could find anywhere, there are Kingston also, but not trusting them again =/, i have and externa HD from AData that has been working excellent for about 2 years)
probably it was defective.
do you guys suggest more a class 4 or class 10 for the increased R/W you mention?
i've been reading and aparently class 10 has a faster write speed but less overall speed so i got a little bit confused =(
jaydaman said:
The problem is the microSD card.
You don't need a higher class microSD card to effectively utilise the swap script. Neither does the swap script directly damage the card.
What happened here is likely a poor quality or defective card that could not handle the increased R/W when using the swap script.
Some may argue that there is increased wear & tear on the microSD card when using the script, but the microSD card, regardless of class, would last a long time before failing.
There have been many reports of Sandisk cards failing in Samsung devices. Sandisk has already acknowledged defective batches of cards. Go google to learn the specifics.
Click to expand...
Click to collapse
I would argue that the script does cause the issue. He's already been through 2 cards, and they weren't SanDisk. The tablet is not designed to run everything from external, so it will cause more stress.
RikRong said:
I would argue that the script does cause the issue. He's already been through 2 cards, and they weren't SanDisk. The tablet is not designed to run everything from external, so it will cause more stress.
Click to expand...
Click to collapse
Well, if you said that the card failed after a year or so, I would say it could be the high levels of wear & tear due to the script.
But, just a week ??? Come on, that's ridiculous to think that the script could induce such shocking levels of wear & tear on the card to cause it to fail in a week.
Very likely it is a poor quality or defective card.
i agree with jaydaman.
i guess it's worth to add that during the 2 weeks i waited for the replacement of the first MicroSD card i used a Kingston 8Gb class 2 (that was already on my cellphone) and had no problem during those 2 weeks. so maybe it was defective :S.
guess i'll get the AData 32Gb class 10 and hope for the best =/, it's really useless to live without the script as apps wont install or run directly from the "external sd", so that limits the number of apps i can have.
=(
jaydaman said:
Well, if you said that the card failed after a year or so, I would say it could be the high levels of wear & tear due to the script.
But, just a week ??? Come on, that's ridiculous to think that the script could induce such shocking levels of wear & tear on the card to cause it to fail in a week.
Very likely it is a poor quality or defective card.
Click to expand...
Click to collapse
I agree, i have been storing apps on my card since i bought my tab, either with the script, or folder mount,with no prob. Besides, older phones store apps on sdcards almost exclusively, because of small internal memory.
Sent from my GT-P3110 using xda app-developers app
Flash memory like microSD cards are being mass-produced in greater volumes than ever, especially with the popular brands such as Kingston & SanDisk thanks to the proliferation of smart/mobile devices.
It is thus likely that there are more 'lemon' cards with every batch.