I am doing a school project regarding the Meltdown patches and how it affects performance, and was doing some disk benchmarks (CrystalDiskMark).
Current setup is i5-8600K + Samsung 860Evo 250GB, and to my surprise, the Meltdown patch increased performance... in both Read and Write by very small numbers... (did 3 trials).. I tried the 4KiB Q32 T1 test.
So I reasoned that maybe it's because the CPU is too fast for the SSD and ran a CPU stress test in the background while benchmarking the disks
Even on a PCID disabled laptop, while the read speed decreased by 8%, the write speed increased by 20% (without stress test in background)
and I get 7% decrease in disk performance after the patch (36.85 --> 34.27 / 28.66 -->26.66MB/s)
Is this the correct way to benchmark the performance hit caused by the patch? And why does the patch increase performance at low CPU loads? I read the comments on this post: which said something about these disk benchmarks being bad for QD=1 workloads and were bad in simulating real-life scenarios but I wasn't able to understand what he meant.
Thank you for answering!