Why write speed is faster than write speed

vbimport

#1

My SATA controller is SII3512. I am trying to do performance test on two SATA drives. :confused:

I have two different SATA devices: Channel 0 ( /ata0 ) is Sata Hard Drive ( spinning drive ) and channel 1 is flash drive ( /ata1 )
The test consist of the following

  • For every write test : Open (…) , write (…) , close ().
    -For every open test : open (…) , write(…) , close(…)

What bothers me is the read is slower than a write. I put trace in the code and The DMA is not used. I was expecting Flash Drive to be slower than Hard Drive

-> sataBenchAll 5

*************** Starting Serial ATA All Devices Benchmark! ****************

 *********** Starting Serial ATA device [B]/ata0[/B] Benchmark! ************

write 0: 16777216 bytes / 163 ticks = 5.889571 MB/sec
write 1: 16777216 bytes / 166 ticks = 5.783133 MB/sec
write 2: 16777216 bytes / 166 ticks = 5.783133 MB/sec
write 3: 16777216 bytes / 166 ticks = 5.783133 MB/sec
write 4: 16777216 bytes / 169 ticks = 5.680473 MB/sec

read 0: 16777216 bytes / 270 ticks = 3.555556 MB/sec
read 1: 16777216 bytes / 269 ticks = 3.568773 MB/sec
read 2: 16777216 bytes / 270 ticks = 3.555556 MB/sec
read 3: 16777216 bytes / 269 ticks = 3.568773 MB/sec
read 4: 16777216 bytes / 270 ticks = 3.555556 MB/sec

 *********** Serial ATA device /ata0 Benchmark finished! ************


 *********** Starting Serial ATA device [B]/ata1[/B] Benchmark! ************

write 0: 16777216 bytes / 268 ticks = 3.582090 MB/sec
write 1: 16777216 bytes / 277 ticks = 3.465704 MB/sec
write 2: 16777216 bytes / 277 ticks = 3.465704 MB/sec
write 3: 16777216 bytes / 281 ticks = 3.416370 MB/sec
write 4: 16777216 bytes / 277 ticks = 3.465704 MB/sec

read 0: 16777216 bytes / 510 ticks = 1.882353 MB/sec
read 1: 16777216 bytes / 509 ticks = 1.886051 MB/sec
read 2: 16777216 bytes / 510 ticks = 1.882353 MB/sec
read 3: 16777216 bytes / 510 ticks = 1.882353 MB/sec
read 4: 16777216 bytes / 509 ticks = 1.886051 MB/sec

 *********** Serial ATA device /ata1 Benchmark finished! ************

#2

What is the brand and model of both drives? The HDD could be on its way out. You can also make sure you have the latest Firmware flashed to the sata controller.