The Ampere Altra Max Review: Pushing it to 128 Cores per Socket
by Andrei Frumusanu on October 7, 2021 8:00 AM EST- Posted in
- Servers
- Arm
- Neoverse N1
- Ampere
- Altra Max
Conclusion & End Remarks
Our time with the new Altra Max has been interesting, as it’s very much a chip design that quite polarising and pushing some aspects of core scalability to the very extreme.
When Ampere had talked about their plans to put to market a 128-core variant of the Neoverse N1, a 60% increase in cores over their first generation 80-core attempt, we were of course perplexed on how they would achieve this, especially considering the chip is meant to be used on the very same platform with same memory resources, and also on the same fundamental technology – same core microarchitecture, same mesh IP, and same process node.
The Altra Max is a lot more dual-faced than other chips on the market. On one hand, the increase of core count to 128 cores in some cases ends up with massive performance gains that are able to leave the competition in the dust. In some cases, the M128-30 outperforms the EPYC 7763 by 45 to 88% in edge cases, let’s not mention Intel’s solutions.
On the other hand, in some workloads, the 128 cores of the M128 don’t help at all, and actually using them can result in a performance degradation compared to the Q80-33, and also notable slower than the EPYC competition.
I think what we’re seeing here is that Ampere is hyper-optimising themselves into certain workloads. The Altra Max marketing is especially focused around cloud-computing and hyperscaler deployments of the chip. Ampere’s recent announcement earlier this summer, detailing that the company is working on their own custom CPU microarchitecture with specific plans to target such workloads, and abandon the general use case Neoverse Arm CPUs, with Ampere’s description of “general use case” here being mentioned in a negative context, is telling that this is all a deliberate strategy.
What differs a cloud CPU from a regular CPU? I’ll be frank here in mentioning that I don’t have sufficient background on the matter other than to say that memory does not seem to be a focus-point of such workloads. We’re still working on expanding our test suite with more real-world distributed systems workloads to cover such scenarios. By Ampere’s wording of their announcement this summer, and by the very apparent direction of the new Mystique design performance characteristics, it seems we’ll see even greater such extremes in the future.
On the competitive landscape, Ampere is carving out its niche for the moment, but what happens once AMD or Intel increase their core counts as well? A 50% increase in core counts for next-gen Genoa should be sufficient for AMD to catch up with the M128 in raw throughput, and technologies such as V-cache should make sure the HPC segment is fully covered as well, a segment Ampere appears to have no interest in. Intel now has an extremely impressive smaller core in the form of Gracemont, and they could easily make a large-core count server chip to attack the very segment Ampere is focusing on.
Only time will tell if Ampere’s gamble on hyper-focusing on certain workloads and market segments pays out. For now, the new Altra Max is an interesting and very competent chip, but it’s certainly not for everyone.
Related Reading:
-
The Ampere Altra Review: 2x 80 Cores Arm Server Performance Monster
-
AMD EPYC Milan Review Part 2: Testing 8 to 64 Cores in a Production Platform
-
AMD 3rd Gen EPYC Milan Review: A Peak vs Per Core Performance Balance
-
Intel 3rd Gen Xeon Scalable (Ice Lake SP) Review: Generationally Big, Competitively Small
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lemurbutton - Thursday, October 7, 2021 - link
Before AMD can disrupt Intel in the server, Ampere has disrupted AMD. And now Intel is coming back with Saphire Rapids. Doesn't look good for AMD.Teckk - Thursday, October 7, 2021 - link
AMD also has upcoming products, same as other companies :) Competition is good.schujj07 - Thursday, October 7, 2021 - link
Most likely Sapphire Rapids will only get Intel to Epyc Milan or a little past there. Overall ICL Xeon only caught Intel up to Epyc Rome. Initial tests on Milan were good, showing 5-7% better performance which isn't bad, however, it wasn't like what we saw on the desktop side. Turns out the benchmarks were run on a reference platform that AMD hacked to allow 3rd Gen support. Once benchmarks were done on Milan on platforms designed for 3rd Gen the performance jumped by another 10% or more. Basically that put ICL 15-17% behind Epyc Milan and SPR is only supposed to get about 19% more performance.mode_13h - Thursday, October 7, 2021 - link
> Initial tests on Milan were good, showing 5-7% better performance which isn't badInitial tests were flawed, due to non-production hardware/firmware. Check out their update:
https://www.anandtech.com/show/16778/amd-epyc-mila...
schujj07 - Thursday, October 7, 2021 - link
"Initial tests were flawed, due to non-production hardware/firmware."I basically said that in my initial comment.
"Turns out the benchmarks were run on a reference platform that AMD hacked to allow 3rd Gen support. Once benchmarks were done on Milan on platforms designed for 3rd Gen the performance jumped by another 10% or more. "
GreenReaper - Saturday, October 9, 2021 - link
Your initial comment was too long, he didn't read that far before hitting reply.whatthe123 - Thursday, October 7, 2021 - link
icelake is not great in general. it was an improvement over 14nm but the core scaling was not there and their 10nm was still struggling to hit competitive boost clocks. I don't think the uplift they saw between 14nm and icelake reflects sapphire rapids at all considering the major design changes and improved node, but if it does I don't see how sapphire rapids would compete with milan at a lower core count. If its competing with milan then the per-core performance and MT scaling has seen a huge uplift compared to icelake.schujj07 - Thursday, October 7, 2021 - link
Had ICL come out on time people would have been more impressed. The problem that ICL has is since it was soooooo late Intel had to squeeze every ounce of performance out of SKL. Overall ICL is just a short term platform but the performance comparison to SPR.mode_13h - Friday, October 8, 2021 - link
> Had ICL come out on time people would have been more impressed.Depends on what you mean by "on time". If it had come in place of Cascade Lake, then probably. However, if it still followed Cascade Lake, then the clockspeed drop and strong competition from Rome & comparison with Graviton 2 are still unflattering.
If Ice Lake had notched up the clockspeed ladder *and* launched in place of Cascade Lake, then it would've been a very solid entry.
Anyway, I'm sure Intel is still selling every one they can make. People are quick to point out how AMD benefited from Intel's process woes, but the past 5 years' demand surge has provided Intel a very nice cushion. They basically couldn't have picked a better time to falter.
schujj07 - Friday, October 8, 2021 - link
I believe that ICL was supposed to be 2nd Gen Scalable. When Intel found that it wasn't ready, they released Cascade Lake. Even worse was needing to release Cooper Lake for 4-8S systems in 2H 2020.