[dhruvdh]

> Performance per watt was better for Intel

No, not its not even close. AMD is miles ahead.

This is a Phoronix review for Turin (current generation): https://www.phoronix.com/review/amd-epyc-9965-9755-benchmark...

You can similarly search for phoronix reviews for the Genoa, Bergamo, and Milan generations (the last two generations).

[pclmulqdq]

You're thinking strictly about core performance per watt. Intel has been offering a number of accelerators and other features that make perf/watt look at lot better when you can take advantage of them.

AMD is still going to win a lot of the time, but Intel is better than it seems.

[adrian_b]

That is true, but the accelerators are disabled in all cheap SKUs and they are enabled only in very expensive Xeons.

For most users it is like the accelerators do not exist, even if they increase the area and the cost of all Intel Xeon CPUs.

This market segmentation policy is exactly as stupid as the removal of AVX-512 from the Intel consumer CPUs.

All users hate market segmentation and it is an important reason for preferring AMD CPUs, which are differentiated only on quantitative features, like number of cores, clock frequency or cache size, not on qualitative features, like the Intel CPUs, for which you must deploy different program variants, depending on the cost of the CPU, which may provide or not provide the features required for running the program.

The Intel marketing has always hoped that by showing nice features available only in expensive SKUs they will trick the customers into spending more for the top models. However any wise customer has preferred to buy from the competition instead of choosing between cheap crippled SKUs and complete but too expensive SKUs.

[CoastalCoder]

I think Intel made a strategic mistake in recent years by segmenting its ISA variants. E.g., the many flavors of AVX-512.

Developers can barely be bothered to recompile their code for different ISA variants, let alone optimize it for each one.

So often we just build for 1-2 of the most common, baseline versions of an ISA.

Probably doesn't help that (IIRC) ELF executables for the x86-64 System V ABI have now way to indicate precisely which ISA variants they support. So it's not easy during program-loading time to notice if your going to have a problem with unsupported instructions.

(It's also a good argument for using open source software: you can compile it for your specific hardware target if you want to.)

[pclmulqdq]

Wise customers buy the thing that runs their workload with the lowest TCO, and for big customers on some specific workloads, Intel has the best TCO.

Market segmentation sucks, but people buying 10,000+ servers do not do it based on which vendor gives them better vibes. People seem to generally be buying a mix of vendors based on what they are good at.

[adrian_b]

Intel can offer a low TCO only for the big customers mentioned by you, who buy 10000+ servers and have the force to negotiate big discounts from Intel, buying the CPUs at prices several times lower that their list prices.

On the other hand, for any small businesses or individual users, who have no choice but to buy at the list prices or more, the TCO for the Intel server CPUs has become unacceptably bad. Before 2017, until the Broadwell Xeons, the TCO for the Intel server CPUs could be very good, even when bought at retail for a single server. However starting with the Skylake Server Xeons, the price for the non-crippled Xeon SKUs has increased so much that they have been no longer a good choice, except for the very big customers who buy them much cheaper than the official prices.

The fact that Intel must discount so much their server CPUs for the big customers is likely to explain a good part of their huge financial losses during the last quarters.

[andyferris]

Are generic web server workloads going to use these features? I would assume the bulk of e.g. EC2 spent its time doing boring non-accelerated “stuff”.

[everfrustrated]

Intel does a lot of work developing sdks to take advantage of its extra CPU features and works with open source community to integrate them so they are actually used.

Their acceleration primitives work with many TLS implementations/nginx/SSH amongst many others.

Possibly AMD is doing similar but I'm not aware.

[kkielhofner]

ICC, IPP, QAT, etc are definitely an edge.

In AI world they have OpenVINO, Intel Neural Compressor, and a slew of other implementations that typically offer dramatic performance improvements.

Like we see with AMD trying to compete with Nvidia software matters - a lot.

[pclmulqdq]

AMD is not doing similar stuff yet.

[kimixa]

But those accelerators are also available for AMD platforms - even if how they're provided is a bit different (often on add-in cards instead of a CPU "tile").

And things like the MI300A mean that isn't really a requirement now either.

[pclmulqdq]

They are not, at the moment. Google "QAT" for one example - I'm not talking about GPUs or other add-in cards at all.

[Tuna-Fish]

You might not be, but the parent poster is.

QAT is an integrated offering by Intel, but there are competing products delivered as add-in cards for most of the things it does, and they have more market presence than QAT. As such, QAT provides much less advantage to Intel than Intel marketing makes it seem like. Because yes, Xeon (including QAT) is better than bare Epyc, but Epyc + third party accelerator beats it handily. Especially in cost, the appearance of QAT seems to have spooked the vendors and the prices came down a lot.

[tecleandor]

I've only used a couple QAT accelerators and I don't know that field much... What relatively-easy-to-use and not-super-expensive accelerators are available around?