Big differences in transfer speed - USB sticks and SDHC cards

[Dave2002]

I bought a new USB memory stick recently - a 128 Gbyte Kingston. It seemed very slow, and others who had placed reviews reported that it wasn't fast. Today I tried to copy a whole bunch of files - probably about 20 GBytes to the stick, and I think it took around one and a half hours.

Then I thought that wasn't too terrible, compared with some others - a bit slow, but not impossible.

Later I tried to copy some SDHC cards. A couple are high speed Sandisk Ultra - claimed to be 80x. I noticed that I was able to copy about 12 Gbytes in around 2 minutes, so storage with that speed could do the original copy in under 5 minutes. I knew there were differences in transfer rates, but I didn't realise that there is such a huge discrepancy.

Now I'm even wondering if I should send the new USB stick back as not fit for purpose. There's slow and there's ...... almost static ......

[Anastasius]

Thanks for the heads up. I didn't realise there was so much difference in speed.

[Gordon]

I bought a new USB memory stick recently - a 128 Gbyte Kingston. It seemed very slow, and others who had placed reviews reported that it wasn't fast. Today I tried to copy a whole bunch of files - probably about 20 GBytes to the stick, and I think it took around one and a half hours.

Then I thought that wasn't too terrible, compared with some others - a bit slow, but not impossible.

Later I tried to copy some SDHC cards. A couple are high speed Sandisk Ultra - claimed to be 80x. I noticed that I was able to copy about 12 Gbytes in around 2 minutes, so storage with that speed could do the original copy in under 5 minutes. I knew there were differences in transfer rates, but I didn't realise that there is such a huge discrepancy.

Now I'm even wondering if I should send the new USB stick back as not fit for purpose. There's slow and there's ...... almost static ......

https://en.wikipedia.org/wiki/Secure_Digital#.22.C3.97.22_rating

Have a look at this link to the spec for SD card family. It might help to see what card labelling tells you about the performance. The old X rating was basically about READ speeds and often the WRITE speed was a lot less. Also don't forget that the overall speed depends also on your host device's performance and what else it might be doing.

The X rating was based on the old CDROM transfer speed of about 1.2 MBit/s so your 80X HC device should be capable of being READ sustainably [ie non fragmented file transfer] at about 90MBITS/sec ie about 11MBYTES/sec - assuming the device and its host have nothing else to do - and that includes any housekeeping during transfer. That figure defines its READ speed - but what is its WRITE speed?? Again note the use of MB/s ie Mega BYTEs rather than Bits.

Your 12GBYTEs transfer in about 2 mins is about 100MBYTEs/sec which is within the XC spec but does your host support that? Typically devices are sometimes downward compatible which means they adjust to the host and do the best they can which may not be their full capability.

Cheapest cards can be assumed to be the low end of the spec and even not fully compatible with the latest XC/HC etc specs - IF no logo then not compatible. The logo means a licence which in turn means full compatibility.

The fact that your card is a Kingston AND is so large at 128 GBYTEs suggests that it should be compatible with the latest SDXC spec; however, unless the device itself declares it, the speed rating - write and read - may not be defined. Does it have any logo? If so, it should meet a certain speed class rating as a guarantee.

[Dave2002]

Thanks for the heads up. I didn't realise there was so much difference in speed.

Neither did I. Sometimes shear bulk is worth having, even if it's slow, though I have had memory sticks fail, and that's even more problematic if they are large capacity. Some are advertised as USB 2, and others as various grades of USB 3 - though most are advertised as USB 3 now, as the USB standard should ensure compatibilty anyway, and marketeers don't seem to worry much about shading the truth.

Although there are speed differences between devices using USB 2 and USB 3, for some devices it doesn't actually appear to be the interface which slows things down. The overall time will depend on transfer time, plus internal processing. If the internal processing is slow, that will dominate, it's only with fast memory that the transfer time will start to have a significant effect.

Thus with my Sandisk SDHC example, which I estimated might take 5 minutes to transfer a similar amount of data as to the Kingston memory (which took over 90 minutes) - I doubt that it would take three times longer with USB 2 than USB 3, giving a transfer time of about 15 minutes - which is still 6 times faster.

Earlier this year I measured transfer rates to SSD using different interfaces, USB 2, Firewire and USB 3. USB 3 was the fastest, taking about 4-5 seconds for my test file (large), then Firewire which took about 11-12 seconds, and finally USB 2 which took around 16-18 seconds. This was with the same SSD.

I am still wondering whether it's acceptable to Amazon to send that stick back - I can check it further, but for me that really was painfully slow, even if the bulk memory seemed cheap enough.

[Flay]

It's the same for SD cards. The one I had originally with my Olympus E-M10 camera was slow, which was particularly frustrating when deleting pictures. Fortunately last "Black Friday" I spotted an offer on Amazon for a 64GB Lexar SD card which is rated at 1000X giving 150MB/sec. It has made a tremendous difference.

It's a good price here still

[Dave2002]

It's the same for SD cards. The one I had originally with my Olympus E-M10 camera was slow, which was particularly frustrating when deleting pictures. Fortunately last "Black Friday" I spotted an offer on Amazon for a 64GB Lexar SD card which is rated at 1000X giving 150MB/sec. It has made a tremendous difference.

Indeed. Wow - that Lexar does sound fast for an SD card. Once one gets to higher performance storage devices, then the interface may start to have an impact. That kind of performance is needed for new cameras and video camers, which may deliver 4k quality. Partly also the overall behaviour depends on the memory used in the device - e.g video camera or camera - microphones may be less fussy. Some devices have enough in-built storage to buffer data, so can still function with slower storage, but as you mention, that might affect overall operation, depending on what's being done. If there's a need for large storage (e.g video cams, and long takes), then any in-built storage used for buffering can run out, and then the recording to the SD card will probably fail, or at least terminate prematurely.

Older cameras probably won't work that fast anyway. I think the Sandisk Ultra card I mentioned earlier is rated at 80MB/sec, which is still a lot faster than some other storage. Until the cards all become as "cheap as chips" (silly phrase, as fish and chips may be expensive these days!) there is no need to use faster cards with some (possibly older) devices, and there can be significant price differentials.

We should all watch out for offers on or around Black Friday - which I think is November 25th this year.

[Dave2002]

It's a good price here still

Seems to be similar at am.uk now, so would save me having to enter more details into a new site.

https://www.amazon.co.uk/s/ref=sr_1_...367&sr=8-1-acs £23.99 Will probably order a few given your tip. Could perhaps also function as extra storage on some laptops and other machines.

https://www.mymemory.co.uk/SDXC/Lexar/Lexar-64GB-Lexar-Professional-1000x-SD-%28SDXC%29-Card-UHS-II-U3---150MB_s

These might not get any cheaper, even on Black Friday. It might also be worth checking Lexar (and maybe others) to see if they do high speed USB memory sticks at reasonable prices.

[Dave2002]

Just tried out the Lexar card recently purchased for £23.99. Initially didn't work - so had to reformat in one of my computers, then worked in the camera.

Unfortunately the am.uk price has gone up to over £30, and the mymemory.co.uk price is now £24.99 (big deal!) but they don't actually have any in stock.

I expect in the future these things will get cheaper, and perhaps faster still - though I'm not sure about that for these applications.

In my camera it looks as though it will record video at about 3 mins/Gbyte, so one of those cards could contain about 3hrs of HD video. I suppose 4k video would consume memory like it's going out of fashion. One thing I would like to know is how to take long video shots with an SDHC card - as I recently noticed that the camera gives up when 4Gbytes have been recorded - FAT32 limitation I think. Is this an inevitable "problem" with regular cameras which have a video record capability, or can it be overcome? Perhaps that would be a reason to use some form of digital camcorder.

I was in Maplin this morning, and noticed some Sandisk SSDs - a little over £200 I think it was for about 960 Gbytes (probably this one - http://www.maplin.co.uk/p/sandisk-96...a-ii-ssd-a36rr) - which seemed to be at 500 Mbps, but there was another model (Samsung?) - with a different mounting format (maybe M.2?) which was considerably more expensive per Gbyte, but claimed to be at 2500 Mbps. The first would easily go in an external case for USB 3 connector - and they can be obtained for under £10 if you know where to look. That's not bad for fairly fast external drives, but of course a regular hard drive of similar size can be obtained for about £50 - but it won't be as robust, and probably not as fast.

There seems to be considerable variation in the pricing of SSDs - even for ones which are nominally similar in speed. I don't suppose many of us have a great deal of experience of that yet.

[Anastasius]

.....as I recently noticed that the camera gives up when 4Gbytes have been recorded - FAT32 limitation I think. Is this an inevitable "problem" with regular cameras which have a video record capability, or can it be overcome?

Correct. The only way to get round it is to either split the data (which relies on the s/w in the camera and probably non-existent) or reformat to NTFS (but the camera might not handle that and Macs don't like NTFS, IIRC)

Perhaps that would be a reason to use some form of digital camcorder.

Nope. Only if the can split the data...see earlier.

[Dave2002]

Nope. Only if they can split the data...see earlier.

Some definitely can do that.
I used a Zoom q2hd recently, and the recorder was on for two sessions each about an hour.
Those devices generate multiple files with some form of consecutive numbering.

I did wonder if there'd be a problem if something important was happening exactly at the switchover point, but it doesn't seem difficult to simply trim and join the files together in a video tool, such as Quicktime, and the results seem seamless enough.

I have read (but not confirmed this by any sensible article) that the EU has regulations which restrict recording on still cameras to 30 minutes - though this might be an urban myth, or another anti-EU story.

I didn't think that cameras could do NTFS either - can they? Macs can work with NTFS, it's just not the normal formatting mode. There is software available for purchase to give NTFS capability, or some disk drive or memory manufacturers provide the drivers etc. free with their hard drives or SSDs.

[Anastasius]

Some definitely can do that.
I used a Zoom q2hd recently, and the recorder was on for two sessions each about an hour.
Those devices generate multiple files with some form of consecutive numbering.

I did wonder if there'd be a problem if something important was happening exactly at the switchover point, but it doesn't seem difficult to simply trim and join the files together in a video tool, such as Quicktime, and the results seem seamless enough.

I have read (but not confirmed this by any sensible article) that the EU has regulations which restrict recording on still cameras to 30 minutes - though this might be an urban myth, or another anti-EU story. See below

I didn't think that cameras could do NTFS either - can they? Macs can work with NTFS, it's just not the normal formatting mode. There is software available for purchase to give NTFS capability, or some disk drive or memory manufacturers provide the drivers etc. free with their hard drives or SSDs.

From the web:

One of the significant upgrades in Canon's $3500 5D Mark III DSLR was the extension of the video recording limit from 12 minutes to just under 30 minutes. In the 5D Mark II, 1080p video clips could not be longer than 12 minutes due to the 4GB size limit in the FAT32 file system. DSLRs of that era--the first to record high-definition video--also weren't optimized for video capture, so the processors would overheat after extended periods of recording. That's a problem that still exists today in more compact mirrorless cameras that shoot in 720p or 1080p (like the Sony NEX 7). A 12 minute cap might not have affected professionals using DSLRs for TV shows and independent films--where most individual shots don't last longer than a few minutes--but we definitely felt that crunch when shooting our iPad autopsy video. Newer cameras overcome heating issues with redesigned interior hardware arrangement, and the 12 minute FAT 32 cap is negated with seamless file spanning. But the 30 minute continuous recording cap still stands. And it turns out that it's completely arbitrary.
Back in 2006, the EU controversially decided to classify high-end digital cameras as video recorders, which attached a customs duty of 5-12% for digital cameras imported into Europe. The classification was decided not just based on digital cameras' improving abilities to record video through its lens and sensor, but their ability to record direct input from external sources like televisions. A home video recorder tax would theoretically offset money lost from users recording movies off broadcast television or cable onto digital devices, though the EU has never been very clear on the tax's intent. The tax's consequence, though, has been felt in every digital camera user looking to use a DSLR in place of a camcorder, as camera manufactures would rather limit recording capability in software than raise the price of its cameras (or lower their margins).

[Dave2002]

But the 30 minute continuous recording cap still stands. And it turns out that it's completely arbitrary.
Back in 2006, the EU controversially decided to classify high-end digital cameras as video recorders, which attached a customs duty of 5-12% for digital cameras imported into Europe. The classification was decided not just based on digital cameras' improving abilities to record video through its lens and sensor, but their ability to record direct input from external sources like televisions. A home video recorder tax would theoretically offset money lost from users recording movies off broadcast television or cable onto digital devices, though the EU has never been very clear on the tax's intent. The tax's consequence, though, has been felt in every digital camera user looking to use a DSLR in place of a camcorder, as camera manufactures would rather limit recording capability in software than raise the price of its cameras (or lower their margins).

Thanks for finding that information re the EU issues. Actually I think that for many "ordinary" cameras the technical issues, at least for some models, may still be the limiting factor - at least as they are currently implemented, with files reaching a limit of 4 Gbytes, and the camera not then starting another file. Of course this could be a convenient way for the manufacturers to show compliance with what seems a somewhat arbitrary and unnecessarily restrictive EU ruling, and in this instance it does not seem to favour the consumer. Quite why the camera manufacturers could not have simply restricted input through external sources to 30 mins, if that really was a concern of the EU, I cannot fathom. Restricting direct input through the lens seems very unreasonable.

One might also question whether the whole approach of restricting what users might do is sensible.

[Anastasius]

.....
One might also question whether the whole approach of restricting what users might do is sensible.

Since when did the word 'sensible' and 'EU' appear in the same sentence (apart from this one, of course)

[Dave2002]

Lexar do seem to have some of the fastest USB memory sticks, too - but there are significant differences in pricing.

https://www.amazon.co.uk/gp/product/...A3P5ROKL5A1OLE 400 MB/s around £28 for 64 Gbytes, but around double that for 128 Gbytes.

Slower, but with more capacity

https://www.amazon.co.uk/gp/product/...A3P5ROKL5A1OLE 128 Gbytes but "only" up to 150 MB/s at about £22 per stick.

[Dave2002]

Not yet a "scientific" test, but I bought this Lexar USB stick - https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1

I then copied a folder with some video files etc. - about 3.77 Gbytes to a Kingston stick - took about 9mins 30 secs.

I then repeated the copy of the folder to the Lexar stick - took under a minute.

That's a very significant difference - around an order of magnitude.

Even halving the time would have been significant, and indicate useful potential, but the difference on this "test" was very substantial.

With speed differences like that, it could be worth paying a bit more for memory to get much faster performance. Obviously if bulk memory storage is required, and transfer times are not important, then cheaper memory may be justified, but if there's only a modest premium for faster sticks then they may represent the "way to go". Of course reliability is another factor - I'm assuming similar levels of reliabilty.

I've only had one USB stick failure (which was complete) that I'm aware of, over quite a number of years - probably at least ten, but they do happen.