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diglloydTools DiskTester Java to Debut Soon
Related: diglloydTools, DiskTester, Java, memory, Other World Computing, SSD
Previous version of Java (prior to JDK 20 or 21 not sure) could not deliver the required I/O speed. It had to do with the way buffer memory was handled between the JVM and native code. That now looks to be fixed in JDK 20 and 21, and possibly earlier.
After 4 very long days of coding, I now have developed a DiskTester Java (dtj) that actually outperforms the original native version.
Indeed, dtj is capable of I/O speeds up to 100 GiB/sec on the 2023 Mac Pro M2 Ultra, that is, when the OS has cached the data. That is actually quite a feat requiring buffering and threading. But it’s important for testing new superfast PCIe SSD cards, like the OWC Accelsior 8M2.
The feature set is not as extensive but equivalent commands to DiskTester fill-volume, DiskTester creates-files, DiskTester run-sequential, DiskTester run-sequential-suite are all implemented and working impressively fast.
For context, 100 GiB/sec exceeds the memory bandwidth of the 28-core 2019 Mac Pro. The M2 Ultra memory bandwidth leaves Intel machines far behind in the dark ages.
Here, 108.7 GiB is being read (cached) at a scrazy-fast 100202 MiB/sec = 105 MB/sec.
MacPro:diglloydUtil $ dtj read --bufsize 32M --numbuf 24 ~/Desktop/out
...
#238: 108.7 GiB @ 100202 MiB/sec overall 100202 MiB/sec
Validating
Shown below are the results from classic DiskTester vs DiskTester Java (dtj).
DiskTester Java delivers higher and more consistent performance (orange and blue lines) vs DiskTester class (red and green), being designed to extract every last ounce of performance out of the drive, thus yielding a picture of best possible drive performance. Which is the whole idea.
Of course, tests can be run with different parameters., as before, and even different APIs (Java or POSIX).
WOW that OWC FX SSD is impressively fast! Reads are as fast as the Thunderbolt bus allows, and write speed far exceeds most SSDs.
Write: 2255 MiB/sec = 2365 MB/sec
Read: 2921 MiB/sec = 3062 MB/sec
Get OWC FX SSD at MacSales.com.
