01-26-2011 05:24 PM
28 12
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  1. jonaddis84's Avatar
    Im looking for a 16gb replacement for my 8gb stock card. Was about to buy a Sandisk from amazon but its a class 2. I found another thread with people comparing different class cards read and write speeds, but none of them said whether it translated into noticeable differences.

    A class 2 card is as low as $21
    A class 6 card is as low as $61

    If Im not even going to NOTICE that difference outside of the SD card speed test app then I dont want to fork over an extra $40
    10-30-2010 09:33 AM
  2. eldub1's Avatar
    A class 4 will do. It wil also save you a few dollars.
    10-30-2010 09:45 AM
  3. thekarens's Avatar
    I got a class 6 off Amazon for around 37. I'm happy with it.

    Sent from my HTC Evo 4g
    10-30-2010 09:51 AM
  4. smileshappy's Avatar
    I got a komputer bay 16 gig class 6 from amazon for a really cheap price. Should check into it. I am happy with mine.
    10-30-2010 11:05 AM
  5. Gekko's Avatar
    it takes me about 15 minutes to copy a 2GB movie from my Netbook to my EVO's included microSD card via the included HTC USB cable. would another brand or type or class of microSD card be significantly faster? my guess is no.
    10-30-2010 12:43 PM
  6. Caitlyn McKenzie's Avatar
    Only around twice as fast.
    10-30-2010 01:41 PM
  7. Gekko's Avatar
    well the 2GB mp4 movie plays beautifully on my EVO using the stock video player BUT fast forwarding capability is not good. it kicks me out of the movie when i try to use the scroll bar to fast forward. not sure if this is because the file is so big (2GB) or just a limitation of the video player - or both. no big deal for me because watching movies on EVO is more of a novelty for me and not something i would do often if ever. interesting test though.
    10-30-2010 01:46 PM
  8. IAmSixNine's Avatar
    The higher class rating is only noticable for transfereing larger files. So yes to those who have 2 gig files, and yes to me who has 3 gigs of music.
    General day to day use of the device no, but yes if you record in HD, technically the higher recording needs class 4. Class 2 is a bare minimum for HD recording. Again, just my opinion and only backed up by a few things i have read.
    I am looking for a class 4 or 6 32G card because i do occasionally want to record in 720P and not get choppy recording or play back.
    Also if i update my music it would be nice to have it go faster.
    10-30-2010 02:29 PM
  9. Kevin OQuinn's Avatar
    The higher class rating is only noticable for transfereing larger files. So yes to those who have 2 gig files, and yes to me who has 3 gigs of music.
    General day to day use of the device no, but yes if you record in HD, technically the higher recording needs class 4. Class 2 is a bare minimum for HD recording. Again, just my opinion and only backed up by a few things i have read.
    I am looking for a class 4 or 6 32G card because i do occasionally want to record in 720P and not get choppy recording or play back.
    Also if i update my music it would be nice to have it go faster.
    Kingston is the only brand right now that makes a class 4 32gb microSD.
    10-30-2010 07:20 PM
  10. Caitlyn McKenzie's Avatar
    The higher class rating is only noticable for transfereing larger files. So yes to those who have 2 gig files, and yes to me who has 3 gigs of music.
    General day to day use of the device no, but yes if you record in HD, technically the higher recording needs class 4. Class 2 is a bare minimum for HD recording. Again, just my opinion and only backed up by a few things i have read.
    I am looking for a class 4 or 6 32G card because i do occasionally want to record in 720P and not get choppy recording or play back.
    Also if i update my music it would be nice to have it go faster.
    The EVO does not need anything more than Class 2 for HD recording ever. The 720p recording option records at ~1MB/s, which is half of a Class 2's rated speed.

    Also, whoever mentioned playback of a 2GB movie and fast forward crashing: no, that's just an issue of the app.
    10-31-2010 12:59 AM
  11. willy900wonka's Avatar
    There is another aspect to choosing your microsd card. That is battery consumption. Not going to go into details. There is only a finite amount of electricity a chip can consume before it overheats. So if a sd card is limited@ some speed it's because it takes more energy than what it can dissipate, to go faster. So if a sd chip is rated at 10 and you use it at 2 then you are using one fifth of the rated max current for the sd. Since all sd's are close in total consumption at their rated max, you do the math.
    Please Google this and don't take my word for it.
    10-31-2010 10:58 AM
  12. deaofly's Avatar
    I have arc media player which plays great and can skipping to any part of the video and it wont skip or lag, but they are 300mb vids. You can try it out.
    10-31-2010 01:34 PM
  13. Caitlyn McKenzie's Avatar
    There is another aspect to choosing your microsd card. That is battery consumption. Not going to go into details. There is only a finite amount of electricity a chip can consume before it overheats. So if a sd card is limited@ some speed it's because it takes more energy than what it can dissipate, to go faster. So if a sd chip is rated at 10 and you use it at 2 then you are using one fifth of the rated max current for the sd. Since all sd's are close in total consumption at their rated max, you do the math.
    Please Google this and don't take my word for it.
    Not only is this post nonsensical, it has absolutely no point to it.
    10-31-2010 02:58 PM
  14. willy900wonka's Avatar
    Not only is this post nonsensical, it has absolutely no point to it.
    Can you be specific? Hand waving doesn't count. You're obviously an EE.
    10-31-2010 04:21 PM
  15. PookiePrancer's Avatar
    Not only is this post nonsensical, it has absolutely no point to it.
    After reading that 4 times, I'm going to have to go with your assessment. That was so painful to read, I don't WANT to Google anything about it.
    10-31-2010 09:13 PM
  16. mmhhc's Avatar
    Easy guys. Willy900wonka is just saying that the max current usage is the same regardless of class number, i.e.:

    Imax,class2 = Imax,class4 = .... = Imax

    He is also assuming that the current consumption scales linearly with read speed, something like:

    I,actual = Imax*(read speed/max read speed)

    So if a movie only requires 1MB/s to read from the card, then a class 2 is at 50% power while a class 10 is at 10% power.

    Is Willy Wonky? I don't know. I "googled it" but could not find the answer. I even looked on manufacturers web-sites.

    Willy, please point us in the right direction.
    PookiePrancer likes this.
    10-31-2010 11:50 PM
  17. splmonster's Avatar
    The EVO does not need anything more than Class 2 for HD recording ever. The 720p recording option records at ~1MB/s, which is half of a Class 2's rated speed.

    Also, whoever mentioned playback of a 2GB movie and fast forward crashing: no, that's just an issue of the app.
    If that was the case it wouldn't skip during HD playback on recorded videos.
    11-01-2010 12:08 AM
  18. Jerzyiroc's Avatar
    I've had two different class 2 sd cards and I have no issues with HD playback
    11-01-2010 12:57 AM
  19. splmonster's Avatar
    I've had two different class 2 sd cards and I have no issues with HD playback
    I don't have issues with the playback of HD videos from say "my computer". Now ones that I record on the phone is a different story. Choppy playback when viewing the videos I have recorded with the phone in 720p. I have seen it happen on about 20 different Evo's. So it can't be just mine.. Has to be the class 2 does not have sufficient enough write speed for 720p.
    11-01-2010 03:40 AM
  20. willy900wonka's Avatar
    Easy guys. Willy900wonka is just saying that the max current usage is the same regardless of class number, i.e.:

    Imax,class2 = Imax,class4 = .... = Imax

    He is also assuming that the current consumption scales linearly with read speed, something like:

    I,actual = Imax*(read speed/max read speed)

    So if a movie only requires 1MB/s to read from the card, then a class 2 is at 50% power while a class 10 is at 10% power.

    Is Willy Wonky? I don't know. I "googled it" but could not find the answer. I even looked on manufacturers web-sites.

    Willy, please point us in the right direction.
    You're right about the assumption, it does scale, once over a baseline threshold. Read on chip leakage.
    The actual data I have is from design (spec) books (paper) distributed by mfgs. They should be available on line. Pick a chip by mfg. then google its design specifications.

    http://www.datasheetlocator.com/

    A rhetorical question is why are low power sd's rated (when normalized to speed) and priced similarly to high speed sd's?

    The other route is load the "currentwidget" from market, and run an sd dependent apk while using different sd's.
    11-01-2010 04:42 AM
  21. Caitlyn McKenzie's Avatar
    If that was the case it wouldn't skip during HD playback on recorded videos.
    I don't have issues with the playback of HD videos from say "my computer". Now ones that I record on the phone is a different story. Choppy playback when viewing the videos I have recorded with the phone in 720p. I have seen it happen on about 20 different Evo's. So it can't be just mine.. Has to be the class 2 does not have sufficient enough write speed for 720p.
    This was an issue in the ROM, it was fixed in the latest update. If you're still having issues, you probably have a bad SD card.

    I am 100% factually certain that Class 2 is enough. The math is not going to lie, seriously. I can record anything and play it back on my phone smoothly, on my stock SD card.

    In addition! You are talking about READ speed, which SD cards are not rated for. If it plays correctly on your PC, then you automatically know the SD card was fast enough.

    Finally, keep in mind that the EVO will drop frames when recording video in anything other than perfect lighting conditions. This is a camera issue, NOT an SD card issue. You could have a Class 10 card and it would still happen.

    You're right about the assumption, it does scale, once over a baseline threshold. Read on chip leakage.
    The actual data I have is from design (spec) books (paper) distributed by mfgs. They should be available on line. Pick a chip by mfg. then google its design specifications.

    Global Electronic Components Datasheet Locator

    A rhetorical question is why are low power sd's rated (when normalized to speed) and priced similarly to high speed sd's?

    The other route is load the "currentwidget" from market, and run an sd dependent apk while using different sd's.
    Here's the real question: why in the world do we care about the power usage of a microSD card when the power usage is so infinitesimal that even discussing the difference would be ridiculous?
    11-01-2010 09:28 AM
  22. Jerzyiroc's Avatar
    I don't have issues with the playback of HD videos from say "my computer". Now ones that I record on the phone is a different story. Choppy playback when viewing the videos I have recorded with the phone in 720p. I have seen it happen on about 20 different Evo's. So it can't be just mine.. Has to be the class 2 does not have sufficient enough write speed for 720p.
    I used to have that problem when I first got the 2.2 update where it would playback on my phone choppy. I use the VaelPak rom and since I belive version 2.1, I haven't had an issues with it. I don't think he's messed around with it to allow better playback. I am slightly overclocked but that wouldn't affect the read write speed. I don't want to sound like I'm dismissing the sd class as being anissue, I do apologize if I came out like that. I just wonder if it's actually an issue of sd class, something else, or a combination of things. But I will have to agree with Vincent, a class 2 should be more than enough for HD recording.
    11-01-2010 12:51 PM
  23. add309's Avatar
    The higher class rating is only noticable for transfereing larger files. So yes to those who have 2 gig files, and yes to me who has 3 gigs of music.
    General day to day use of the device no, but yes if you record in HD, technically the higher recording needs class 4. Class 2 is a bare minimum for HD recording. Again, just my opinion and only backed up by a few things i have read.
    I am looking for a class 4 or 6 32G card because i do occasionally want to record in 720P and not get choppy recording or play back.
    Also if i update my music it would be nice to have it go faster.
    the last update got rid of the choppy playback on 720p videos so it has absolutely nothing to do with the sd card
    11-02-2010 01:05 PM
  24. kilo720's Avatar
    Does anybody know how the classes affect music cuase i wannq put 10gb of music my sd card
    12-28-2010 11:37 AM
  25. anon(49767)'s Avatar
    The class isn't going to have any effect on music playing. A class 2 is plenty fast enough for playing music - if it wasn't, all the stock users with class2 cards and gigs of MP3s on their EVO (myself included) would be screaming. You can put as much music as your card can hold.
    12-28-2010 01:16 PM
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