Fake Flash Card Results topic

I used FakeFlashTest to test a card I had received, and would like some understanding of the results please...

This is the log: What is the actual usable space??


FAKEFLASHTEST v1.1.1 [SSi]
DRIVE 4 - 249.9GiB Generic- SD/MMC
FFT - Quick Size Test (destructive)
F: (no label) DRIVE 4 - 249.9GiB Generic- SD/MMC

Writing marker blocks to drive 4
5% complete - 103 min 14 sec remaining
10% complete - 97 min 39 sec remaining
15% complete - 92 min 17 sec remaining
20% complete - 86 min 52 sec remaining
25% complete - 81 min 24 sec remaining
30% complete - 75 min 57 sec remaining
35% complete - 70 min 31 sec remaining
40% complete - 65 min 8 sec remaining
45% complete - 59 min 42 sec remaining
50% complete - 54 min 16 sec remaining
55% complete - 48 min 51 sec remaining
60% complete - 43 min 25 sec remaining
65% complete - 38 min 0 sec remaining
70% complete - 32 min 35 sec remaining
75% complete - 27 min 9 sec remaining
80% complete - 21 min 44 sec remaining
85% complete - 16 min 18 sec remaining
90% complete - 10 min 52 sec remaining
95% complete - 5 min 26 sec remaining
100% complete - 0 min 1 sec remaining
Reading back marker blocks...
5% complete - 0 min 38 sec remaining
10% complete - 0 min 36 sec remaining
15% complete - 0 min 34 sec remaining
20% complete - 0 min 32 sec remaining
25% complete - 0 min 27 sec remaining
30% complete - 0 min 26 sec remaining
35% complete - 0 min 25 sec remaining
40% complete - 0 min 23 sec remaining
45% complete - 0 min 21 sec remaining
50% complete - 0 min 18 sec remaining
55% complete - 0 min 17 sec remaining
60% complete - 0 min 15 sec remaining
65% complete - 0 min 13 sec remaining
70% complete - 0 min 12 sec remaining
75% complete - 0 min 9 sec remaining
80% complete - 0 min 8 sec remaining
85% complete - 0 min 6 sec remaining
90% complete - 0 min 4 sec remaining
95% complete - 0 min 2 sec remaining
*** ERROR *** reading from drive 4 at Sector 14892474
Memory tested in blocks of 25600 sectors.

BAD MEMORY from sector 14892474 (7,271.7158MiB) to sector 524281274 (255,996.7158Mib)
Test took 6717 seconds.

*** FAILED ***

DEVICE HAS DUPLICATE OR BAD BLOCKS!

Recommended maximum usable partition size: 7,259.2158Mib (approx. Last good Sector=14892474)

Unplug and re-connect the drive, then reformat it using Windows or RMPrepUSB.