The Ampere Altra Max Review: Pushing it to 128 Cores per Socketby Andrei Frumusanu on October 7, 2021 8:00 AM EST
SPEC - Multi-Threaded Performance - Aggregate
Switching over to the aggregate geomean scores for the suites, we see a more moderate view of the generational improvements of the Altra Max chip:
In the integer suite, the M128-30 only sees a 6-10% advantage over the Q80-33 depending on the 2- or 1-socket scores. It’s a smidge faster than the EPYC 7763, but there’s more considerations to have than just the total scores.
In the floating-point suite, the system also sees rather lacklustre figures of only 3-4% advantage of the M128-30 over the Q80-33.
The general problem of these scores showcase is a trend of the new Altra Max design, and that is that it’s not as general-purpose as we tend to expect for a CPU. Even though we see regular large workload gains of 30-45%, the way the suite is designed for the “base” scores is that we’re running all workloads with the same number of instances, something which at 128 cores on the Altra Max inevitably leads to performance regressions in anything that is more demanding on memory and caches.
When we first heard of the Altra Max only featuring a 16MB cache, we were quite pessimistic of this aspect of the design, well – that was also true of the 32MB cache of the 80-core Altra, where performance in some workloads just can not scale well beyond a certain core count due to the shared resource contention.