Canonical Continues Exploring Ubuntu x86-64-v3 Images - Now In Microsoft's Cloud

[phoronix]

Phoronix: Canonical Continues Exploring Ubuntu x86-64-v3 Images - Now In Microsoft's Cloud

Ubuntu maker Canonical has spent the past several months exploring Ubuntu x86-64-v3 based images for leveraging the x86_64 micro-architecture feature level capabilities to target the level embracing AVX/AVX2, FMA, BMI2, and other instructions supported largely since Intel Haswell and AMD Excavator era processors. As shown in benchmarks Ubuntu x86-64-v3 builds can deliver better performance for the AMD/Intel systems of the past number of years. Canonical's latest foray in this area is offering up Microsoft Azure images that are tailored for x86-64-v3...

https://www.phoronix.com/news/Ubuntu-x86-64-v3-Images-Azure

[Mark Rose]

For AWS at least there isn't an easy way to filter images or instances by extensions. I can imagine moving to a higher base requirement would cause an increase in support cases as there people using "previous generation" hardware for various reasons.

[-MacNuke-]

As a sidenote: Microsoft is moving to x86-64-v2 in the next 24H2 Windows 11 update. https://arstechnica.com/gadgets/2024...ome-older-pcs/

[Anux]

As a sidenote: Microsoft is moving to x86-64-v2 in the next 24H2 Windows 11 update. https://arstechnica.com/gadgets/2024...ome-older-pcs/

Where did you get that v2 thing from? The article only speaks of POPCNT which is more like v1.0.1

[-MacNuke-]

Where did you get that v2 thing from? The article only speaks of POPCNT which is more like v1.0.1

Well, it is part of SSE4 (SSE 4.2 for Intel CPUs) so it is basically x86-64-v2. And the listed AMD CPUs with POPCNT but not SSE 4.2 are not supported by Windows 11 for other reasons.

[Anux]

Well, it is part of SSE4 (SSE 4.2 for Intel CPUs) so it is basically x86-64-v2. And the listed AMD CPUs with POPCNT but not SSE 4.2 are not supported by Windows 11 for other reasons.

No? Its part of BMI https://en.wikipedia.org/wiki/X86_Bi...nstruction_set and my argument was, that they won't use any SSE3/4 instructions which v2 would imply. Just this single instruction.

POPCNT is already supported by first gen Core and Bulldozer i think. If MS was to use all extensions that are supported by Core 8000 and Zen 2 upwards they could easily use v3. Not sure why they don't because that would at least justify not supporting older CPUs. Maybe they plan to do so if enough people have upgraded to W11.
But most SSE/AVX instructions are not that useful for kernel tasks anyway.

[-MacNuke-]

No?

From the page:

"While Intel considers POPCNT as part of SSE4.2 and LZCNT as part of BMI1, both Intel and AMD advertise the presence of these two instructions individually."

In the end the result is the same. There are no CPUs that Windows 11 supports, don't have SSE4.2 and have the POPCNT instruction. If they will have a hard requirement on other instructions is practically irrelevant at that point. If you are on 24H2 you can basically assume x86-64-v2.

[Anux]

"While Intel considers POPCNT as part of SSE4.2

Ok, apart from not using xmm registers and not being a SIMD operation, I will let Intel have their way of definition.

If you are on 24H2 you can basically assume x86-64-v2

But if you go only by what Win11 supports you can assume x86_64_v3. Still no sign that any of those instructions will be a requirement. If Intel decides to release a new crippled ATOM CPU with only SSE2, TPM2 and POPCNT (let's pray they don't) it would be a W11 compatible CPU and every software that assumed AVX or SSE2/3 will not run there.

[-MacNuke-]

Ok, apart from not using xmm registers and not being a SIMD operation, I will let Intel have their way of definition.

Windows 11 requires full SSE 4.2 now https://www.tomshardware.com/softwar...-will-not-boot

[Anux]

Windows 11 requires full SSE 4.2 now https://www.tomshardware.com/softwar...-will-not-boot

24H2 preview, but yes it will most likely come and possibly even more stuff (AVX)? At least then their statement about unsupported CPUs would make more sense.