While the AMD Ryzen AI Max+ PRO 395 and Ryzen AI Max+ 395 are very similar processors just as the Ryzen PRO processors are to other non-PRO parts, one of the differences with the AMD PRO Technologies come down to AMD Memory Guard providing full system memory encryption. From the HP BIOS with the ZBook Ultra G1a there is a convenient toggle for this full memory encryption support and thus I decided to carry out some benchmarks to measure the performance cost to this memory encryption feature on this AMD Strix Halo SoC.
With not too often having the Ryzen “PRO” variants in the lab at Phoronix for testing, while having the HP ZBook Ultra G1a review sample in for testing with the Ryzen AI Max+ PRO 395 flagship SoC, I was curious to measure the AMD Memory Guard performance impact.
AMD Memory Guard is enabled by default on AMD PRO processor platforms. Within the HP BIOS it was indeed on by default but with a checkbox to easily disable this memory security feature if so desired. The AMD Memory Guard whitepaper promotes it as a security feature for laptops that are always/often-on and helping to protect any passwords / security keys / private information stored within RAM. AMD Memory Guard works without any software modifications and any operating system.
The AMD Memory Guard whitepaper talks of “no significant impact to system performance” with less than 1% for some benchmarks but PCMark 10 System Performance on Windows reported in the whitepaper to be a 3.4% hit. I ran my own benchmarks to see what the AMD Memory Guard encryption impact looks like for Strix Halo.
With the HP ZBook Ultra G1a with AMD Ryzen AI Max+ PRO 395, I ran the same benchmarks while “Full encryption of main memory (DRAM)” was enabled (the default) and then disabled from the HP BIOS. The same Ubuntu 25.04 setup was used for all testing with no other changes besides toggling this memory encryption option. Dozens of workloads were then tested to see the performance impact of this full DRAM encryption.
Contrary to the few data points in the whitepaper, I was able to find a number of workloads where the full DRAM encryption did provide a measurable impact but overall it wasn’t that costly of a feature for the added security benefits. And considering all of the other out-of-the-box Strix Halo tests to date on Phoronix with the HP ZBook Ultra G1a laptops were with this AMD Memory Guard feature enabled, Strix Halo still delivers very robust performance with or without AMD Memory Guard.
