@Test
  public void testPopulate5kbwrites() {
    ENTRY_SIZE = 1024 * 5;

    /*
     * OP_COUNT can be increased/decrease as per the requirement. If required to be set as higher
     * value such as 1000000 one needs to set the VM heap size accordingly. (For example:Default
     * setting in build.xml is <jvmarg value="-Xmx256M"/>
     *
     */
    OP_COUNT = 1000;
    UNIQUE_KEYS = Boolean.getBoolean("DRP.UNIQUE_KEYS");
    RegionAttributes ra = region.getAttributes();
    // final String key = "K";
    final byte[] value = new byte[ENTRY_SIZE];
    Arrays.fill(value, (byte) 77);
    String config = "ENTRY_SIZE=" + ENTRY_SIZE + " OP_COUNT=" + OP_COUNT + " UNIQUE_KEYS="
        + UNIQUE_KEYS + " opLogEnabled="
        + !Boolean.getBoolean(GeodeGlossary.GEMFIRE_PREFIX + "disableOpLog") + " syncWrites="
        + Boolean.getBoolean(GeodeGlossary.GEMFIRE_PREFIX + "syncWrites");
    if (ra.getDiskStoreName() != null) {
      config += " diskStoreName=" + ra.getDiskStoreName();
    } else {
      config += " [" + ra.getDiskWriteAttributes() + "]";
    }
    log.info(config);

    long startTime = System.currentTimeMillis();
    if (UNIQUE_KEYS) {
      for (int i = 0; i < OP_COUNT; i++) {

        region.put(i, value);
      }
    } else {
      for (int i = 0; i < OP_COUNT; i++) {
        region.put("" + (i + 10000), value);
      }
    }

    long endTime = System.currentTimeMillis();

    // region.close(); // closes disk file which will flush all buffers
    ((LocalRegion) region).forceFlush();

    long et = endTime - startTime;
    long etSecs = et / 1000;
    long opPerSec = etSecs == 0 ? 0 : (OP_COUNT / (et / 1000));
    long bytesPerSec = etSecs == 0 ? 0 : ((OP_COUNT * ENTRY_SIZE) / (et / 1000));

    String stats = "et=" + et + "ms writes/sec=" + opPerSec + " bytes/sec=" + bytesPerSec;
    log.info(stats);
    System.out.println("Stats for 5kb writes :" + stats);
  }
Disk region perf test for Persist only with sync writes.
geode-core/src/integrationTest/java/org/apache/geode/internal/cache/diskPerf/DiskRegionPersistOnlySyncJUnitTest.java