Thus, one needs to sustain a random byte stream for several seconds to get a correct notion of the performance profile.įor testing disk capacity, I found F3 by Michel Machado also does performance profiles while checking the disk capacity:Īs log as your adapter can sustain the maximum i/o speeds the will detect most problem cards. In conclusion, when testing these cards keep in mind some models have over 8MB+ of RAM caching with low-level compression and sector sparing. The clones out of china are easy to spot given they are usually re-branded older model cards that usually max out at 4MB/s. However, I learned that even the identical model are different after cloning the disk images onto several dozen cards.Įven off-the-self from a few local retailers, you will get slightly different write speeds and capacities from the same source.Įxcluding the host system workload: sometimes you’ll get average card writes at 8MB/s, and other times it’ll climb to around 16MB/s. Notably, the Sandisk Extreme include wear levelling (should last longer), but we have yet to see the prices adjust to sane levels. I use those little ARM boards quite a bit, and found that the service life of Sandisk Ultras is quite good. Posted in Parts, Raspberry Pi, Slider Tagged raspberry pi, sd cards Post navigation
So beware: if the price it too good to be true, it very well may be. Even getting a brand name card may not help since some are counterfeit. There are a lot of fakes floating around marked with higher capacities than they actually support. also checked the capacity of the SD cards. measured much higher speeds running the same tests using a Mac with a USB dongle. The cards are capable of much more than the Pi can deliver. Another interesting result is that the Pi’s data bus greatly limits the access speeds. For example, a system doing a lot of small database reads and writes might work better with one SD card while a system storing and then streaming videos might work better with another card. That lead to determining which software tools to use for the measurement. The discussions in the blog about what to measure were as interesting as the actual results. tests were solely on the Pi while were on Windows 7, Ubuntu, and a Pi. over at Raspberry Pi Spy also tested SD cards and found similar differences. The no-name cards fared pretty badly but even among the brand names there is considerable variation. He ran a number of tests on cards ranging from cheap no-names to well-known brand names.
wondered exactly how different cards would affect system performance.
They are not all created equal and the differences can impact the running of your Raspberry Pi, no matter which model. There is surprising variation in the performance of SD cards.
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