sdhc cards

R

R.J.

Member
Talking to a salesperson they recomend that i use a card that is a class 6. Any thoughts on this? Thanks
 
You can use any SDHC card that is rated Class 4 or faster. Class 6 doesn't cost much (if any) more than Class 4, so it's fine; it won't change the video performance at all but it might offload to your computer faster.

Stick with the best brands. Just like with anything, there's good stuff out there and there's junk out there. If you cheap out on your media, don't be surprised if your media cheaps out on you.
 
I have used a lot of Kingston cards with no problems. Adata is the only card that has given me problems.
 
I agree that Adata is problematic.
Not from my own experience, mind you, as i have never bought any.
But I have read in multiple areas that they are cards best stayed away from.
 
I know that a significant number of folks have had problems with A-Data SDHC cards, but I've got a 4GB A-Data (class-6) that works just fine. Of course, I always format in-camera. I'm mildly surprised at how many problems some folks seem to have with A-Data flash memory cards. They've been making extremely reliable RAM memory for computers for several years now, so it's not like they are some fly-by-night operation. Maybe they outsource their flash memory products to a somewhat less than reliable manufacturer operating a prison labor camp in China. Who knows.

Class-6 cards do tend to cost about the same as Class-4, until you get to the 32GB cards. My son picked up a Patriot class-4 32GB card for about $80 and it works just fine. The feedback on those, at Newegg, is pretty good too. (Patriot also makes very good quality RAM memory for computers.)
 
I using an 8GB Class 4 PNY card without problems. There are a few others I'll have to try soon...


Bob Diaz
 
I actually use that 4GB A-Data card often, since it's so dang easy to simply copy the contents straight to a single layer DVD for a whole whopping 15 cents (really cheap for storage, with no screwing around spanning disks, or anything of the sort). If Newegg ever does a real blow-out deal on 4GB SDHC cards that should work in the HMC40 (like for $5 ea w/free shipping), I might grab a handful. I rarely shoot a single clip that exceeds 20 minutes.
 
please, someone start writing down this stuff for future reference...i'm subbin to as many informative threads as possible.,
 
I just got a Toshiba 8 GB, Class 4 card, it seems to work OK.


Known Good Cards:
Toshiba 8 GB, Class 4 card
PNY 8GB Class 4 card
Kingston cards
SanDisk Extreme III
Lexar Platinum
Transcend
​

Mixed Reports:
A-Data card (some report problems)
​

Any additions and corrections to this list are welcome...


Bob Diaz
 
Robert M Wright said:
I know that a significant number of folks have had problems with A-Data SDHC cards, but I've got a 4GB A-Data (class-6) that works just fine. Of course, I always format in-camera. I'm mildly surprised at how many problems some folks seem to have with A-Data flash memory cards. They've been making extremely reliable RAM memory for computers for several years now, so it's not like they are some fly-by-night operation. Maybe they outsource their flash memory products to a somewhat less than reliable manufacturer operating a prison labor camp in China. Who knows.

Class-6 cards do tend to cost about the same as Class-4, until you get to the 32GB cards. My son picked up a Patriot class-4 32GB card for about $80 and it works just fine. The feedback on those, at Newegg, is pretty good too. (Patriot also makes very good quality RAM memory for computers.)
Click to expand...


All right, I make flash memory for a living, and thought I would chime in on this subject.

1. You cannot make GB size SDHC memory in a sweatshop/ prison camp/ whatever (this will be important in just a minute, bear with me). That spiffy red laser pointer you use in meetings is 670nm. That means that it is 670 billionths of a meter from crest to crest of the wavelengths of light coming out of it. That's pretty small. GB size flash will be on 65nm technology (or smaller). That means that the structures made in there will be about 1/10th the size of a wavelength of red light. Just keeping the air clean enough to make that costs a fortune, but failing to keep it clean is even more expensive as dust way way way smaller than cigarette smoke will ruin product. You don't want to know what one drop of sweat could do (sodium is the bane of semi-conductors!). Oh, a very very fine human hair is about 17,000 nm wide (thick hair is more like 180,000nm). The environment has to be carefully controlled because the process is subject to changes in temperature, humidity, and pressure. We spent over a year raising the temperature 1 degree Fahrenheit as a cost saving measure.

2. The flash memory chips are made on a silicon wafer (round platter of silicon, commonly 8" or 12" in diameter these days, with 25 wafers to a "lot." Each wafer will have hundreds, if not thousands of chips on it. Different classes of memory come from the same wafer. What happens is that each chip from each wafer is tested and then rated. Those that test as class 4 are class 4. Those that test as class 6 are class 6. We generally have an expectation of how product will perform, but minor process variations mean a difference in performance (and this is the same story with microprocessors).

Ok, so there is no one making 32GB memory in their basement, so what happens?

Well, I could buy some class 4 memory, and peel that sticker off and glue a new one on that says class 10, then sell it for more. A lower end maker (with more process variation) could get their label replaced with Toshiba or what have you.

Or, I could get my gritty paws on a bunch of failed product destined for disposal, and put "Premium" stickers on that. Then I could sell it for whatever I could fake it as.

So, the point here is that just because it says Sandisk class 6 doesn't mean that Sandisk thought it was worthy of class 6, or even of sale. It doesn't even mean that Sandisk actually made it.

You need to buy from a reputable dealer (like our beloved hosts, for example), because stickers are cheap. Even a dealer can get burned by this if their supplier pulls a fast one, but at least you have someone who will stand behind you if that happens.
 
Great post, v3rlon.

Bob, I'd like to add to the mixed results category Taiwanese version of Transcend cards bought via NewEgg. I got (2) bad cards from them back in August '09.

As and aside, this topic has been covered at length in the HMC150 category, so it's also a great resource because of similar recording media technology.
 
Known Good Cards:
Toshiba 8 GB, Class 4 card
PNY 8GB Class 4 card
Kingston cards
SanDisk Extreme III
Lexar Platinum
​
Mixed Reports:
A-Data card (some report problems)
Transcend (most report OK, but there is a chance of bad cards)
​
In reading v3rlon's posting, I have no doubt that he does work in the semiconductor industry, he shows a lot of knowledge of the process involved. (I used to work in TRW's microelectronics lab many years ago, OK late 1970s...)

Back then the products seem quite tame by today's standards, we build 4 bit and 8 bit 20 MHz A/D converters and 8 bit x 8 bit --> 24 bit x 24 bit binary multipliers. I worked in the test lab, so I knew the real performance of our products.

We would test the parts, like multipliers, and find that not every part could meet the 80 nanosecond specification, but could function at the slower 120 nanosecond time. Thus we would sell the premium parts at the higher cost and the slower parts at the lower cost. However, as time passed, we would get higher and higher yields for the premium parts. Many times premium parts were marked as slower parts, in order to fill the orders.

Now if you paid more and got a premium part, it really did work within the 80 nanosecond specification. For those who purchased the slower parts, many times they also worked within the 80 nanosecond specification, BUT not always. A number of the slower parts would fail the 80 nanosecond test.

.....

This brings me back to the issue of class 2 and class 4 memory cards. Assuming that we are not dealing with a fake, a class 2 memory card may have class 4 performance, but not always.

Given that some people are willing to put poison in children's milk to make a buck, it should be no surprise that they are just as willing to take a class 2 card and mark it as class 4 or 6. Worse yet, they'd be just as happy to take defective product and sell it as Class 10.

As I've said before; always take any new memory card, record a few clips to it, play it back, and format it. If you repeat this several times, without problems, chances are it's OK. Remember it's not a given, but the more you use the card without problems, the higher the odds are it's OK.

You need to buy from a reputable dealer (like our beloved hosts, for example), because stickers are cheap. Even a dealer can get burned by this if their supplier pulls a fast one, but at least you have someone who will stand behind you if that happens.
Click to expand...

The memory cards are our "tape" now, so it's not smart to buy for some unknown, just because they offer really low prices.



Bob Diaz
 
Bob, you will get 'mixed' reviews on ALL the cards. I can google right now and find bad performance reviews on Toshiba, PNY, Kingston, Lexar, etc.

The only ones that should be 'mixed' are the ones that have high 'consistant' performance reviews, and I hate to say it, but that would be the A-data cards.

I haven't checked on Patriot brands, so at this moment I cannot say anything positive or negative.

But with all of my SLR's, I only use transcend or SanDisk because they have the highest loyalty of users and less reported fault rates (unofficially. This is through my own homework.)

I would recommend to anyone to go to NewEgg, Tigerdirect & Amazon and read the reviews of each card. Then you will start to get the real pulse.

So for me it boils down to performance & value.

SanDisk has the best overall performance grade, but is also the highest priced card.
Lexar is next on that scale followed by Transcend (where Transcend has the best value.)

Value doesnt just mean 'buying cheap', but rather buying cheap and NOT having to buy again any time soon.

Again this is through my own research and not meant to push or sway.

I will say this though. I am using the same Transcend cards thought I bought 2 years ago and not a single failure yet. No data loss, no formatting/writing issues, no compatibility issues, nothing.
 
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If you look at feedback, for all the Patriot SDHC cards, at Newegg, on the whole it seems pretty similar to feedback for the Transcend SDHC cards.
 
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