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allenxml 于 2015-11-8 09:25 编辑
Once we started exploring IO consistency, nearly all SSD manufacturers made a move to improve consistency and for the 2015 suite, I haven't made any significant changes to the methodology we use to test IO consistency. The biggest change is the move from VDBench to Iometer 1.1.0 as the benchmarking software and I've also extended the test from 2000 seconds to a full hour to ensure that all drives hit steady-state during the test.
For better readability, I now provide bar graphs with the first one being an average IOPS of the last 400 seconds and the second graph displaying the standard deviation during the same period. Average IOPS provides a quick look into overall performance, but it can easily hide bad consistency, so looking at standard deviation is necessary for a complete look into consistency.
I'm still providing the same scatter graphs too, of course. However, I decided to dump the logarithmic graphs and go linear-only since logarithmic graphs aren't as accurate and can be hard to interpret for those who aren't familiar with them. I provide two graphs: one that includes the whole duration of the test and another that focuses on the last 400 seconds of the test to get a better scope into steady-state performance.

Given the higher over-provisioning and an enterprise-oriented controller, it's no surprise that the SSD 750 has excellent steady-state random write performance.

The consistency is also very good, although the SSD 750 can't beat the 850 Pro if just focusing on consistency. When considering that the SSD 750 provides nearly three times the performance, it's clear that the SSD 750 is better out of the two.

At the initial cliff the performance drops to around 15K IOPS, but it quickly rises and seems to even out at about 22-23K IOPS. It actually takes nearly an hour for the SSD 750 to reach steady-state, which isn't uncommon for such a large drive but it's still notable.
I couldn't run tests with added over-provisioning because NVMe drives don't support the usual ATA commands that I use to limit the LBA of the drive. There is similar command set for NVMe as well, but I'm still trying to figure out how to use them as there's isn't too much public info about NVMe tools.

以上内容转自AnandTech,2.2W的Steady-State 4k IOPS random write 与intel p3700 2TB的17W IOPS怎么能是一个级别呢?看人家评测要看仔细一点啊,下面这条里面已经说明原因了。

再给你加个我自己测试的帖子
/thread-1313467-1-1.html单论峰值也不是750能比的,AS SSD只不过是SSD评测届中的鲁大师而已,根本跑不满。
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