Smart Media Card Experiments

• The performance of the smart media card is quite close to the spec’s definition.

• However, the program overhead and driver’s limit will downgrade the performance

Measure Spec

Total OriginalCode

Overhead Remove

Total Spec

Erase 2s 2ms 2s 2ms

Write 8s 323us 250us 6.5s 200us

Read 2s 72us 47us 1.2s 38us

528-Byte Page Read Operation- Random Access : 12µs(Max.)- Serial Page Access : 50ns(Min.)

Fast Write Cycle Time- Program Time : 200µs(Typ.)- Block Erase Time : 2ms(Typ.)

For 1024 blocks, that is 16 MB.

Transfer Type MaximumTransfer Size

Control Endpoint 0 4KB

Control (Other Endpoints)

64KB

FDBench - Disk Benchmark(Unit: KB/s) Read Write Random Read Random Write

ATA Hard Disk 43967 37222 13427 18830

SATA Hard Disk

46800 49254 10112 27765

Genesys 15712 7691 15715 1960

Sandisk 16491 8048 15952 2514

Transcend 14528 11415 14275 2030

NTFS – Random Write

NTFS Observations

• The metadata files will always allocated at the same LBA, and there are some frequently modified data such as $MFT, $LOG.

• When performing random write operations, NTFS will read before writing

• Design a SSD maintain policy for NTFS to overcome the side effects on flash memory.