SD Card Random Access Time - is this really what we are looking for?
Please move this thread to the General Forum
I thought I knew which was the decisive thing about SD card compatibility/performance with WP7.
Random access time
, as most would jump to say, but apparently this theory proves to be wrong in practice... or maybe I'm missing something
Transcend class 6 - 4GB
Random R/W: ~5.1 MB/s (read)/ ~0.025
Transcend class 6 - 8GB
Random R/W: ~4.6 MB/s (read)/ ~0.040
In short, despite having slightly better CrystalDisk Mark
Random Write results, Card B
performes MUCH WORSE on my HD2 running Mango than Card A
I mean 3-5 minutes to download and install an app from Marketplace (eg. Accuweather, Appflow, etc.), while the other one does it in max. 30 seconds!!!
Until the progress bar reaches to 50% the speed is about the same but from then on, Card B
stuggles to finish (I assume the bar shows the download progress in the 1st half and the install progress in the 2nd half)
A few notes:
- the underperforming card was checked for errors with Easeus Partition Manager and it has none, also no bad sectors;
- both cards were tested in the exact same conditions, both formatted the same way and on the same PC, both tested on the same phone, etc.;
- the testing sequence was as follows (every single time): phone off > format sd card > hard reset > connect to wifi > sign in > download apps
- the experiment was repeated several times, always having the same outcome.
So what could possibly be the explanation for this?
Is it not the Random Accesss Time the key criteria we are looking when choosing a good SD card for our phones? If it is, where did I go wrong?
If not, what is it then?