Meltdown & Spectre: Analyzing Performance Impacts on Intel's NUC7i7BNH

Concluding Remarks

While the primary purpose of this exercise was just to update our datasets for future system reviews, it none the less proved to be an enlightening one, and something worth sharing. We already had an idea of what to expect going into refreshing our benchmark data for Meltdown and Spectre, and in some ways we still managed to find a surprise or two while looking at Intel's NUC7i7BNH NUC. The table below summarizes the extent of performance loss in various benchmarks.

Looking at the NUC – and really this should be on the mark for most SSD-equipped Haswell+ systems – there isn't a significant universal trend. The standard for system tests such as these is +/- 3% performance variability, which covers a good chunk of the sub-benchmarks. What's left then are more meaningful performance impacts in select workloads of the BAPCo SYSmark 2014 SE and Futuremark PCMark 10 benchmarks, particularly storage-centric benchmarks. Other than those, we see certain compute workloads (such as the 2nd stage of the Agisoft Photoscan benchmark) experience a loss in performance of more than 10%.

On the whole, we see that the patches for Meltdown and Spectre affect real-world application benchmarks, but, synthetic ones are largely unaffected. The common factor among most of these benchmarks in turn is storage and I/O; the greater the number of operations, the more likely a program will feel the impact of the patches. Conversely, a compute-intensive workload that does little in the way of I/O is more or less unfazed by the changes. Though there is a certain irony to the fact that taken to its logical conclusion, patching a CPU instead renders storage performance slower, with the most impacted systems having the fastest storage.

As for what this means for future system reviews, the studies done as part of this article give us a way forward without completely invalidating all the benchmarks that we have processed in the last few years. While we can't reevaluate every last system – and so old data will need to stick around for a while longer still – these results mean that the data from unimpacted benchmarks is still valid and relevant even after the release of the Meltdown and Spectre patches. To be sure, we will be marking these results with an asterisk to denote this, but ultimately this will allow us to continue comparing new systems to older systems in at least a subset of our traditional benchmarks. Which combined with back-filling benchmarks for those older systems that we do have, lets us retain a good degree of review and benchmark continuity going forward.