Puppy Linux Discussion Forum

[otropogo]

I bought a Dane-Elec Proline Class 10 200X SD card and tested it in my USB3 card reader. The card's packing guarantees minimum write speed of 10MB/s, but I recorded speeds under 4MB/s and as low as 3.3MB/s under Windows 7.

The same file write as slowly as 1.7MB/s under Lupu528 using the Linux driver.

To eliminate the possibility of the reader or the system being at fault, I ran exactly the same write tests with a Compact Flash card several years old, and the latter wrote almost three times faster.

Under Windows 7, which offers a detailed report of the write progress, the card seemed to be extremely slow getting underway. In a write of under three minutes, it was crawling along writing between 120KB and 1MB/s for the first 50 seconds. It took another 20 seconds to hit peak speed at under 4.5MB/s, and slowed down again at the end.

The highest write speed recorded in other tests, copying a single large file (the test above was of a folder holding almost 2,000 text files), was still only 12MB/s. In my experience so far, under both Windows and Puppy, the fastest write speeds are obtained when writing large single files, such as isos.

I've contacted Dane-Elec support about it, and am waiting for their response.

Dane-Elec support suggested I exchange the card for another at the retail outlet. I did, and ran the same tests, with exactly the same results...

In my tests, the "guaranteed minimum write speed" would be more aptly named the "guaranteed maximum write speed", which I find to be aroun12 to 14MB/s for a large single file.


It may still be good value for the money. I see the entire line is OVERPRICED at 50% off at The Source in Canada until the 19th. But it could be a very poor bargain if the advertised minimum is required by your camera to maintain burst capacity.