Go Back   Steve's Digicams Forums > Digicam Help > Memory Cards, Microdrives, Card Readers

Reply
 
Thread Tools Search this Thread
Old Aug 14, 2002, 7:54 PM   #1
Junior Member
 
Join Date: Aug 2002
Posts: 9
Default Lexar vs Sandisk

Hi Folks-

I recently purchased a Sandisk Ultra 512 MB CF card. I understood it to be a 16x card, 2.4 MB/sec.

In my Nikon 880, it was twice as slow as my Lexar 8x card.

Multiple tests of filling the camera buffer and waiting for it to finish writing to the Sandisk Ultra card was 10 seconds compared to 4-5 seconds with a Lexar 160 MB 8x card.

So I sent it back and am now waiting for delivery of a Lexar 24x 512 MB card.

Anyone have any idea why Sandisk Ultra is twice as slow as Lexar 8x?

Sandisk tech support sez that the larger cards will be slower as they fill up, but the card was empty and just formatted in the camera.



[Edited on 8-15-2002 by nomad]
nomad is offline   Reply With Quote
Sponsored Links
Old Aug 14, 2002, 10:35 PM   #2
NHL
Senior Member
 
NHL's Avatar
 
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,547
Default

The speed rating is only applicable to professional dSLR that can fully use them... Beside the rated Mb/s is measured at the IDE interface (ie PC/laptop) and has no relevance with what a slower camera can do!

On consumer camera like yours or almost anything below $2k, the camera itself is too slow for the cards. That's why test comparison between flash cards are of no use to anyone. The same flash card which is fast on one brand of camera may be slower on another brand or vice versa.

It has more to do with how each camera orders it's buffer output to the flash, and how they line up with the block/page in that flash, ie if the card match with your camera it'll be faster! BTW vendors change the internal organization of flash to improve yield and maximize their profit without reflecting on the actual MB. So the flash that you buy today, may not be the same a month from now!

[Edited on 8-15-2002 by NHL]
NHL is offline   Reply With Quote
Old Aug 14, 2002, 10:48 PM   #3
Junior Member
 
Join Date: Aug 2002
Posts: 9
Default

Thanks for responding.

Due CF cards require specific support to take advantage of faster memory?

It will be interesting to see how the 24X Lexar performs.

The 8x Lexar card is faster than any other card that I have.

What is perplexing is that the Sandisk Ultra is 2x slower than an 8x Lexar. Hmmm...
nomad is offline   Reply With Quote
Old Aug 14, 2002, 11:00 PM   #4
NHL
Senior Member
 
NHL's Avatar
 
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,547
Default

You just have to try different brand yourself, don't rely on someone else different brand of camera... Or look @ a Nikon 880 user group (ie a 995 will have a different result than yours)

Are you really shooting at that speed or you just want to try to see which one is faster. In normal use it should not matter, but it's bugging you right? Take the total file size and divide by the # of seconds and you are nowhere close to the advertised speed (which is for read). I bet you the Lexar even though slower at read is actually faster @ write, but vendors usually don't advertise the slower write time, it won't sale!

[Edited on 8-15-2002 by NHL]
NHL is offline   Reply With Quote
Old Aug 14, 2002, 11:30 PM   #5
Junior Member
 
Join Date: Aug 2002
Posts: 9
Default

Yes, I take pics that fast. But that is really not the point.

I like nature pics, and due to the fact that the 880 is not a SLR, especially for it's great macros, I rely on it's auto focus.

Insect photography especially requires taking as many pics as possible before they fly away. Auto focus, as you probably know, is, well, especially on Nikon cameras that for some srange reansn willl not have AF assist, shaky at best.

It will truly be interesting to see if the 24x Lexar is faster than the 8x Lexar and the 16x Sandisk.


If indeed 16x Sandisk Ultra is slower than an 8x Lesar in some cameras, it should be part of it's stats.

So, are you saying that only some cameras support the Sandisk Ultra? That the published write speeds are camera specific?

Every time I've purchased a faster Lexar card the 880 performance has improved. But not so with the Sandisk Ultra. it is 2x slower.
nomad is offline   Reply With Quote
Old Aug 14, 2002, 11:40 PM   #6
NHL
Senior Member
 
NHL's Avatar
 
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,547
Default

Look for the * asterisk that tell the actual write time. The x is usually associated with read time... and not write!

http://www.stevesforums.com/forum/vi...d.php?tid=1178

For example take a look at this OEM:

http://www.toshiba.com/taec/componen...lashseries.pdf

The read is 6.5 Mb/s, but the write time is only half 3.2 Mb/s. What worse is the asterisk for the 16/32Mb the write time is down to a paltry 1.5Mb/s. Plus remember theses are all raw ATA speed at the PC/IDE interface, with a slower camera with loads of SW your 880 is even much slower than that!

[Edited on 8-15-2002 by NHL]
NHL is offline   Reply With Quote
Old Aug 15, 2002, 9:04 AM   #7
Senior Member
 
sjms's Avatar
 
Join Date: Jul 2002
Posts: 2,735
Default

NHL and i have an on going discussion on subjects related to this. he is correct to a certain extent with most of his statements. my experience with sandisk cards is the they tend to advert more than they deliver. i feel you will see a minor difference in the camera but don't expect it to be a monumental speed increase. all the info he said is pretty much spot on and the tech support is also correct. but there is a difference in (and where our opinions diverge)the controllers in the card. this is the logic device that will essentially control the memory in the card and how it will be addressed. the 880 is optimized in a certain way where speed is not number 1 priority. every camera has a comprmise. unfortunately as you increase in dollars yen or your choice of currency there will be decrease in the compromise factor.

the most important thing to remember is that digital photography is in its infancy. we have a long way to go.

if you look at the current crop of dslrs i wouldn't own one. they are the poorest investment in the market today. the level of compromise in design is just too great. i use them by NPS or rent.
sjms is offline   Reply With Quote
Old Aug 15, 2002, 6:39 PM   #8
Junior Member
 
Join Date: Aug 2002
Posts: 9
Default

I received the Lexar 24x card and it is no faster than the 8x. Looks to me that the 880 is hardware limited in write time.

Lexar makes great cards, but it's totally not clear from advertising that cameras may be limited in write speed regardless of memory speed.

Lesson learned.

I really had not considered hardware limatations, because each time I purchased a faster card it was faster. But, for the 880, it looks like 8x about is the limit.

But I still don't understand why the 16x Sandisk was 2x slower than the 8x Lexar. I guess, if you have an 880, buy Lexar.

I'd love a dSLR, because autofocus works about 50% of the time with the 880. Why, why, why won't Nikon have AF assist? Hello! Nikon!

It is truly frustrating. But nonetheless, I've been able to take some truly beautiful pics with my lowly 880 digicam. It's maco is supurb, asside from the fact that it only has 2 f-stop settings which causes depth of field problems in even bright sunlight.


I'm in complete agreement abut the dSLR's . I'd love to have one, but I'll "suffer" with my 880 for a year or two more. dSLR's lose all of their value in abut a year.

BTW, what ever happened to Foveon?

Thanks to all who responded. I'm a first time poster and welcomed the response.
nomad is offline   Reply With Quote
Old Aug 15, 2002, 8:37 PM   #9
NHL
Senior Member
 
NHL's Avatar
 
Join Date: Jun 2002
Location: 39.18776, -77.311353333333
Posts: 11,547
Default

nomad

Let me try to explain:

1. 16x is the advertised read time (ie the slower write time is usually wtitten in small print or hidden)

2. The Sandisk could have a slower write time than the Lexar, but I doubt it...

3. It's organization is larger (512Mb vs 160 Mb), and I believe this is the key as to why it's slower in an 880 (but probably real fast in a 5000/5700 for example.)

A memory location in a 'NAND' flash can not be randomly written over like a Random Access Memory, but a whole block need to be erased first and re-written even though just one location need to be changed... For example, to change a picture in a block, every pictures in that block need to be erased first and rewritten!

What happen is probably the block/page size of this Sandisk 512Mb device does not match with your 880 buffer, ie it's probably twice as large, so even though your camera need to write only 1/2 as much to flash, this 512Mb flash still need to complete the writes for the other 1/2. May be and just may be the 160Mb Lexar block size happen to match your 880!

However with a 5000 or 5700 with a buffer twice as large, theses cameras might be much faster with the 512Mb Sandisk than the 160Mb Lexar which only have a block size 1/2 as much. The Lexar 512Mb 24x just happens to run into your 880 HW/SW limitation, but again it could be faster on another camera.

Do you understand? or I just lost you...
NHL is offline   Reply With Quote
Old Aug 15, 2002, 11:26 PM   #10
Senior Member
 
sjms's Avatar
 
Join Date: Jul 2002
Posts: 2,735
Default

in short what he said is the card gagged on the input speed into the sandisk from the camera

[Edited on 8-16-2002 by sjms]
sjms is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 9:31 PM.