SanDisk Ultra 30mb/s

[justine_k]

<p>Has anyone used the "new" SanDisk Ultra cards that supposedly write at 30mb/s? It seems like quite the good deal and a huge jump over what they used to write at...listed as the same as the Extreme III right now.</p>

<p>Are the claims that it's just as fast legit or are they actually a lot slower?</p>

[frank_skomial]

<p>The SanDisk 30 MBytes/sec is fast for 24 MBits/sec HD AVCHD video, but chokes on D700 after the buffer is reached, storing 8 pictures per second NEF files in 14 bits mode, but that does not mean thst the speed is not legit. Is just not fast enough for some use.</p>

<p>You need to determine your devices speed needed. Sandisk also makes 60 and 90 MBytes/sec cards.</p>

<p>There are usual complaints from those who use slow USB ports, slow card readers, or slow computers or cameras, but that may not be the card fault.</p>

[leighb]

<p>The 8 GB SanDisk Extremes that I just got are spec'd at <strong>60 MB/sec</strong>. I see no reason to doubt the rating.</p>

<p>Obviously the sourcing hardware has to support these high speeds, or the transfer will occur at the highest rate supported by the hardware.</p>

<p>- Leigh</p>

 

[Ed_Ingold]

<p>I've only seen Sandisk Ultra II cards rated at 20 mb/s, Extreme III at 30 mb/s, Extreme at 60 mb/s and Extreme Pro at 90 mb/sec. The ratings are usually optimistic, but this sounds like a typographical error. I use Extreme cards (60 mb/s) in my D3 and DTE video recorder (25 mb/s minimum). Once the buffer in the D3 fills up, it continues to crank along at about 2 fps.</p>

[leighb]

<blockquote>

<p>The ratings are usually optimistic, but this sounds like a typographical error.</p>

</blockquote>

<p>Hi Edward,</p>

<p>Not sure what the typographical error might be. The speed is printed on the card as "60MB/s" with the 's' in lower case, so it's not a question of them using upper case for everything. By industry standard MB is the abbreviation for MegaBytes, as compared with Mb which is Megabits.</p>

<p>My 60 MB/s 8GB SanDisk Extreme says UDMA (actually UDMA 5) on the front. The UDMA 5 mode supports transfer rates up to 100 MBytes/sec. The 45 MB/s card does not specify the DMA mode.</p>

<p>Per the SanDisk website, their 90 MB/s Extreme Pro card requires UDMA 6 for full-speed transfer. That mode supports a maximum 133 MB/s transfer rate.</p>

<p>- Leigh</p>

<p>refs:<br>

SanDisk CF page<br>

http://www.sandisk.com/products/dslr/sandisk-extreme-pro-compactflash-card</p>

<p>Wikipedia Compact Flash page<br>

http://en.wikipedia.org/wiki/CompactFlash</p>

 

[Ed_Ingold]

<p>I was refering to the claim of 30 mb/s for a Sandisk <strong>Ultra</strong>. Sandisk claims 90 mb/s for the <strong>Extreme Pro </strong>(printed on the face of the card and on their website). I doubt they will go any faster, regardless of the interface.</p>

[leighb]

<blockquote>

<p>I doubt they will go any faster, regardless of the interface.</p>

</blockquote>

<p>OK. I give up.</p>

<p>Why would <strong>ANY</strong> product go faster than it specified speed?</p>

<p>- Leigh</p>

<p> </p>

[Dieter Schaefer]

<p>You can read here http://www.robgalbraith.com/bins/multi_page.asp?cid=6007<br>

about the write speeds of the older SanDisk cards for your camera<br>

and here: http://www.robgalbraith.com/bins/content_page.asp?cid=7-10044-10297<br>

about the newer ones. None actually reaches the speed that is written on them - and what write speed you actually get depends strongly on your camera. On my D200, it hardly makes a difference if I use the old Ultra II or the older Extreme III or Extreme IV - it makes a big difference on the D300 though.</p>

[Ed_Ingold]

<p><em>That mode supports a maximum 133 MB/s transfer rate.</em></p>

<p>You mentioned this. Why does it matter what the maximum rate is? You would need an e-SATA reader to get anywhere close to the faster card rates, and the cheapest one is nearly $900.</p>

[leighb]

<blockquote>

<p>Why does it matter what the maximum rate is?</p>

</blockquote>

<p>Because UDMA is an electronics industry standard. It has nothing to do with a particular application.</p>

<p>You were criticizing the card specifications based on how it would perform in a particular piece of equipment.</p>

<p>Totally irrelevant nonsense.</p>

<p>- Leigh</p>

<p> </p>

[justine_k]

<p>OK............Back on subject :-)! </p>

<p>No, there is no typographical error. The new ULTRA's (yes, the ULTRA's) are speced to 30MB/s. It takes about 2 minutes on the SanDisk website to confirm the speed of their new cards, which does indeed go up to 90 MB/s. </p>

<p>But my question was more along the lines of if the claim of 30MB/s were accurate on the Ultras....which apparently no one knows.<br>

<br />I wasn't particularily interested in "my equipment" performance with it. I was more curious in a hypothetical standpoint how well the new Ultra's are performing as a whole in regards to their supposed speed.</p>

[Ed_Ingold]

<p>I'm not sure how you would test the ultimate transfer rate without specialized equipment. I obtain a speed of 18-20 MB/s with an Sandisk USB2 reader and 30-33 MB/s with a Sandisk Firewire reader (FW400, 40-45 MB/s with FW800) - well below the theoretical maximum - for both Extreme IV (40 MB/s) and Extreme (60 MB/s) cards. Extreme cards are noticeable faster than Extreme IV and Ultra cards in my D3, but I can't put numbers to the experience.</p>

<p>As a footnote, using Firewire with Windows can be an interesting (i.e., disappointing) experience. XPSP2 has a glitch which drops FW400 to FW100, and Win7 has a new driver which "improves" FW performance by requiring extensive handshaking. The trick in Win7 is to select the "Legacy" driver using the Device Manager/Update Driver sequence. The trick in XP is to create a new registry entry and value - not for the timid. In Win7, the speed with the default FW driver is a measely 6 MB/s.</p>

<p>For Leigh - I misunderstood your first post, thinking that it implied you could boost the performance if you used a UDMA6 interface. Unfortunately, there does not appear to be any practical way to come close to that value.</p>

[leighb]

<blockquote>

<p>For Leigh - I misunderstood your first post, thinking that it implied you could boost the performance if you used a UDMA6 interface. Unfortunately, there does not appear to be any practical way to come close to that value.</p>

</blockquote>

<p>Hi Edward,</p>

<p>Having designed computer-based embedded communications systems for over 35 years I'm pretty familiar with interface specs.</p>

<p>There's absolutely no way to assess the maximum transfer rate of any storage medium using any standard interface system. In particular you can't have any operating system, no cables or interconnects of any type, and no other protocol (i.e. FireWire) involved in the test. Those simply invalidate the results. You have to use dedicated hardware designed specifically for the device under test.</p>

<p>I could probably list twenty parameters that affect transfer rate, like source impedance, rise and fall times, ringing, max/min logic levels, etc. Deviation of any of these from the spec'd value will degrade the transfer rate, even when all other parameters are nominal.</p>

<p>I'm quite confident that the SanDisk cards will meet spec in a test jig. I'm equally confident that you'll not likely find any consumer equipment that will achieve that speed. On the other hand, full-spec performance would be expected in laboratory equipment.</p>

<p>Another factor that can degrade transfer rate is noise, which causes errors in the received data. Robust protocols detect these errors and request re-transmission of the faulted data, so some data blocks are sent twice (or more), but only counted once in the throughput.</p>

<p>Just an observation.</p>

<p>Thanks.</p>

<p>- Leigh</p>

[simonpg]

<p>Yes I use these in SD and CF versions and they are great. The download speed is quite fast and sufficient for convenient transfer to your computer storage.<br>

Like you say they represent great value for money.<br>

I limit mine always to 4GB - any larger means too many eggs in one basket.</p>