MicroSD Card performance variance on XO-1.5

[Mikus Grinbergs]

> we definitely need to understand what SD card is behind each "works"
> or "doesn't" report re Record and other write-intensive tasks.

Results from motherboard-unmodified B2 XO-1.5 (SHC9370111D):
[I bought these SD cards myself;  both are 8G, labeled class 6]

 int:0  Mfg 0x1b  OEM 0x534d  Micro SD   Read: 16.5  Write: 8.3
 ext:0  Mfg 0x27  OEM 0x5048  Ext slot   Read: 14.9  Write: 4.8

Note:  when I ran the OFW command multiple times, the numbers reported
for the internal card became lower and lower for each repeat.

[Testing Record-86 on os850 on this machine, I was satisfied with how
the result looked, when recording a video clip in 'High' quality.]

mikus