Author Topic: SD Card Speed  (Read 781 times)

Chris

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SD Card Speed
« on: May 19, 2011, 06:08:16 PM »
I was at Staples today getting an ink cartridge for my printer. While I was there I looked at SD cards because I lost my only 8GB card recently. They had PNY 8GB class 10 cards on sale for $19.99 so I got 2 of them.

After a short period of unscientific testing I have come to the conclusion that there is not a noticable difference in speed between the new PNY class 10, 8GB "professional" cards and my PNY class 4, 4GB optima cards.

Does anyone have a different experience?

keithsnell

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Re: SD Card Speed
« Reply #1 on: May 19, 2011, 07:05:48 PM »
I think it depends greatly on the brand (controller) and type of card.  It takes about 40 seconds to clear a 10-shot buffer when using my 8GB Kingston class 4 SDHC card, and about 8 seconds to clear a 10-shot buffer when using my 16GB SanDisk Extreme (HD Video) Class 10 SDHC-I card (rated at 30MB/s, and comes darn close to that in testing on a few hardware review sites).  It's important to note that the SDHC-I card uses the new UHS-I bus, which quadruples the potential bandwidth across the interface.  (UHS-I cards are backwards compatible with older devices, but won't read or write at the rated speeds when used with devices that aren't UHS-I compliant.  UHS-I cards are compatible with the D7000, but not listed as compatible for any Nikon cameras prior to the D7000.)

I suspect that card speeds will vary greatly across test devices, depending on the read/write performance of the device/camera as much as on the card itself, and of course also dependent on the bus interface.  (I suspect that a high-speed UHS-I card probably has a better chance of meeting its rated speed than a card that isn't UHS-I.  Actually I'm just about certain of that, since the SDHC bandwidth tops out at about 25MB/s with the "old" interface, but is capable of 104MB/s with the UHS-I interface.)

I'm happy with the performance of the Sandisk Extreme SDHC-I cards in the D7000.  They cost me $45.99 per card through Amazon.

Hope this helps,

Keith

Chris

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Re: SD Card Speed
« Reply #2 on: May 19, 2011, 07:25:00 PM »
Thanks Keith. It helps a lot. I wish I would have asked or done some research before buying but I was there and saw the SALE sign. :) I'm satisfied with them but might have prefered the new sdhc-i if I had known.

Chris

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Re: SD Card Speed
« Reply #3 on: May 19, 2011, 08:57:23 PM »
Do you get improved transfer speeds when copying them to the PC? I think that would be more important to me than write speed in the camera. When I have a full card it seems to take forever to copy when I'm waiting.

keithsnell

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Re: SD Card Speed
« Reply #4 on: May 19, 2011, 09:23:43 PM »
Do you get improved transfer speeds when copying them to the PC? I think that would be more important to me than write speed in the camera. When I have a full card it seems to take forever to copy when I'm waiting.

No, I don't get improved transfer speeds when copying them to the PC, but that is primarily because the SD card reader in my computer (which is only a year old) is not UHS-I compliant.  There are however inexpensive (USB) SD card readers on the market now that are SDHC-I compliant and have much higher read speeds.  To be honest, I don't find the time it takes to download a 16GB card to be too long.  (The transfer speed to my PC is just over 7MB/s.)  I just put the card in and let it download in the background and go about doing other things.  Maybe someday I'll upgrade to a faster external card reader, but for now the convenience of the internal reader is nice.

Keith
« Last Edit: May 19, 2011, 09:26:04 PM by keithsnell »