Benchmarks Issues Unmasked!

Before we pass over to the actual benchmarks results, let me tell you something very exciting: we have finally found out the notorious thing, which produced wrong results and confused us a lot. This is Maxtor’s brand technology aka Write Verify. As you might remember, this technology first appeared in Maxtor DiamondMax 60/VL30 HDD family and implied that the HDD could read the freshly written data to make sure that they had been written correctly. Of course, this reduced the HDD performance a lot. All Maxtor hard drives sold in those times had the automatic Write Verify set for first 10 boot-ups by default. And then it was automatically disabled. The company has also released a special WVSET utility, which allows enabling and disabling this option.

Since we need the HDD to show maximum performance during the tests, we always disabled this option with the help of Maxtor’s utility, however, it wouldn’t work with the last generation Maxtor drives. Even though the low write speed reveled during the tests indicated that Write Verify was the one to slow it down, there was no way to disable it. Then we started resorting to all sorts of tricks such as turning the testbed on and off ten times before starting the tests, and the like, but they also didn’t always help. The write speed could grow up to the normal level, but the benchmarks results would again be too different. We couldn’t understand anything.

So, one day HDTach benchmark was terminated in the middle and then started anew. The result was like a bolt from the blue: in the interval where we have already run this test the write speed was high, and then after the termination point it dropped again!

Further experiments showed that new Maxtor drives do perform the Write Verify once for each sector on the first write. And now imagine how greatly this fact affected the results of our (and not only our) test sessions!