Myce/OakGate Entropy Tests
These tests are designed to show performance metrics for
different combinations of Queue Depth and Entropy % (Entropy % is the degree to
which the data that is random and therefore incompressible). Testing with
different Entropy % levels has become important with the advent of controllers,
such as those from LSI Sandforce, that compress data before writing it to NAND.
Controllers that compress data can be expected to perform better with highly
compressible data (i.e. data with low Entropy).
The first test performs 5 minutes of Random 4K writes for
each combination of Queue Depth and Entropy %.
The second test does the same thing for a mixture of Read
and Write traffic (70% Reads, 30% Writes).
4K Entropy Write Test
4K Entropy Write Test – Power Efficiency Mode – Single
Here you can see there is little or no variance in
performance to be found in any of the Entropy tests, as the degree of random
data increases (and this comment applies to all of the test results for the
Myce/OakGate Entropy Tests). We can therefore conclude that the Micron 5100 does
not compress data and we will therefore skip the running and presentation of
further Entropy tests.
4K Entropy 70% Reads 30% Writes Test
As we saw no evidence of compression in the 4K Entropy Write
Test we will skip the presentation of the 70/30 entropy results.
Now let’s head to the next page, to look at Power
Consumption and Data Reliability…..