Measuring The Performance Cost To AMD Memory Guard With Ryzen AI PRO CPUs
While in some workloads there was a very clear performance penalty to having this full DRAM encryption by default, it's important to note that it's by default and included as part of the out-of-the-box testing shown in the prior AMD Strix Halo benchmarking... All of the Ryzen AI Max+ PRO 395 and Ryzen AI Max PRO 390 benchmarks on Phoronix the past few weeks have been with this AMD Memory Guard memory encryption feature enabled as is the default. And still the Ryzen AI Max processors delivered incredible performance over prior AMD Ryzen laptop SoCs and the Intel competition. So disabling the AMD Memory Guard security feature in select workloads would yield just even better performance than already showcased in those prior articles.
Out of nearly 100 benchmarks run for this Full DRAM Encryption comparison, the geo mean of all showed less than a 2% penalty of this AMD Memory Guard provided full memory encryption compared to disabling the feature from the system BIOS. It's a small price to pay for the added security especially on laptops or edge/in-the-field servers. For workloads clocking in a measurable performance difference, it tended to be within a few percent.
Here is a look at the subset of the workloads tested where a measurable difference was observed:
AI workloads, typical Linux server workloads, video coding, Java software, and other memory-intensive applications were where those differences were noted while for web browser use and other light desktop / typical laptop applications there didn't end up being any significant performance impact from AMD Memory Guard.
In case you missed it see the HP ZBook Ultra G1a Linux review to learn more about this laptop tested.
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