AMD Zen 5 Details Emerge with GCC "Znver5" Patch: New AVX Instructions, Larger Pipelines

[AleksandarK]

AMD's upcoming family of Ryzen 9000 series of processors on the AM5 platform will carry a new silicon SKU under the hood—Zen 5. The latest revision of AMD's x86-64 microarchitecture will feature a few interesting improvements over its current Zen 4 that it is replacing, targeting the rumored 10-15% IPC improvement. Thanks to the latest set of patches for GNU Compiler Collection (GCC), we have the patch set that proposes changes taking place with "znver5" enablement. One of the most interesting additions to the Zen 5 over the previous Zen 4 is the expansion of the AVX instruction set, mainly new AVX and AVX-512 instructions: AVX-VNNI, MOVDIRI, MOVDIR64B, AVX512VP2INTERSECT, and PREFETCHI.

AVX-VNNI is a 256-bit vector version of the AVX-512 VNNI instruction set that accelerates neural network inferencing workloads. AVX-VNNI delivers the same VNNI instruction set for CPUs that support 256-bit vectors but lack full 512-bit AVX-512 capabilities. AVX-VNNI effectively extends useful VNNI instructions for AI acceleration down to 256-bit vectors, making the technology more efficient. While narrow in scope (no opmasking and extra vector register access compared to AVX-512 VNNI), AVX-VNNI is crucial in spreading VNNI inferencing speedups to real-world CPUs and applications. The new AVX-512 VP2INTERSECT instruction is also making it in Zen 5, as noted above, which has been present only in Intel Tiger Lake processor generation, and is now considered deprecated for Intel SKUs. We don't know the rationale behind this inclusion, but AMD sure had a use case for it.




Next, we have a larger pipeline design. The Zen 5 integer unit has six ALUs compared to the four found in Zen 4. The Address Generation Unit (AGU) count is also higher, going from three to four. The floating point store pipelines are now doubled, and they are 256-bit each to handle a 512-bit floating point store from a single cycle. Some other instructions like cmov/setcc and floating point shuffles can now be handled by all ALUs in Zen 5, whereas in Zen 4, it was handled only by two ALUs. Apparently, the Zen 5 uArch is now handling most of the AVX-512 operations as a single slot pipeline cycle, rather than the old double pumping, which halved AVX-512 instructions into two 256-bit ones for processing on the 256-bit wide ALUs. Lastly, the patch notes that, once again, there will be no difference between Zen 5 and Zen 5c cores ISA-wise, same with Zen 4 and Zen 4c cores, where the latter only implemented smaller caches.

View at TechPowerUp Main Site | Source

 

[beedoo]

Gimme!

 

[AsRock]

targeting 10-15% IPC improvement.

So they don't know yet ?, expecting and what you get are two different things.

Nice to see AVX to be added though.

 

[Onasi]

So they don't know yet ?, expecting and what you get are two different things.

More likely it’s less “they don’t know” and more “it depends on the workload”.

 

[3valatzy]

They must return to more convenient, "cool" and relatively quiet 95-125W TDPs.
170W CPUs requiring 360mm AIO is prohibitive.

This means that 9000 will be slower than 7000 because of the lower TDP (even if 10-15% IPC increase).

What a ridiculous - super hot CPUs, whiny small and hot M.2 PCIe 5.0 SSDs, super gigantic graphics cards.
All of them - no-go.

 

[ncrs]

[...]The new AVX-512 VP2INTERSECT instruction is also making it in Zen 5, as noted above, which has been present in Intel CPUs since Tiger Lake.

A small correction: this instruction family was present only in Tiger Lake. Official support for it was removed from subsequent Intel processors.

 

[Klemc]

Nextgen AI CPUs...

 

[Daven]

They must return to more convenient, "cool" and relatively quiet 95-125W TDPs.
170W CPUs requiring 360mm AIO is prohibitive.

This means that 9000 will be slower than 7000 because of the lower TDP (even if 10-15% IPC increase).

What a ridiculous - super hot CPUs, whiny small and hot M.2 PCIe 5.0 SSDs, super gigantic graphics cards.
All of them - no-go.

You are thinking about Arrow Lake. That architecture will be slower as its a derivative of Meteor Lake where the IPC went down.

Zen 5 will have a 10-15% IPC increase and clocks up to 6.0 GHz. No one is asking for lower TDP for enthusiast CPUs and most likely the full turbo clocks will use the full 220W of the AM5 socket.

 

[3valatzy]

You are thinking about Arrow Lake. That architecture will be slower as its a derivative of Meteor Lake where the IPC went down.

Zen 5 will have a 10-15% IPC increase and clocks up to 6.0 GHz. No one is asking for lower TDP for enthusiast CPUs and most likely the full turbo clocks will use the full 220W of the AM5 socket.

It is hot. My preference is to avoid it. Because of the heat.

AMD Ryzen 9 7950X Cooling Requirements & Thermal Throttling

High temperature seem to be an issue on the new Ryzen 7000 processors. We're pairing a Ryzen 9 7950X with a $10 stock cooler, a Noctua air-cooler and a 420 mm AIO to get a feel for what the differences are like in terms of °C, MHz and performance in both applications and games.

www.techpowerup.com

 

[Onasi]

No one is asking for lower TDP for enthusiast CPUs and most likely the full turbo clocks will use the full 220W of the AM5 socket.

Uh, citation needed? I see quite a lot of people, both here and on other tech communities, lambasting both Intel and AMD for pushing their chips often beyond the optimal efficiency curve by essentially overclocking them out of the box. That’s why undervolting is popular. Not every enthusiast is drooling at the mouth at the idea of slapping a giant AIO or custom loop on a CPU that, realistically, would lose only single digit performance if dropped down to a level when a decent air cooler is enough.

 

[Daven]

Uh, citation needed? I see quite a lot of people, both here and on other tech communities, lambasting both Intel and AMD for pushing their chips often beyond the optimal efficiency curve by essentially overclocking them out of the box. That’s why undervolting is popular. Not every enthusiast is drooling at the mouth at the idea of slapping a giant AIO or custom loop on a CPU that, realistically, would lose only single digit performance if dropped down to a level when a decent air cooler is enough.

You want a citation that computer enthusiasts don’t want next gen high end parts to be slower than last gen?

BTW the X3D parts are as efficient and low power as you can possibly ask for.

 

[AnarchoPrimitiv]

It is hot. My preference is to avoid it. Because of the heat.

View attachment 334222

AMD Ryzen 9 7950X Cooling Requirements & Thermal Throttling

High temperature seem to be an issue on the new Ryzen 7000 processors. We're pairing a Ryzen 9 7950X with a $10 stock cooler, a Noctua air-cooler and a 420 mm AIO to get a feel for what the differences are like in terms of °C, MHz and performance in both applications and games.

www.techpowerup.com

Avoid Ryzen in favor of what? Intel who is even hotter and uses more power?

 

[Daven]

It is hot. My preference is to avoid it. Because of the heat.

View attachment 334222

AMD Ryzen 9 7950X Cooling Requirements & Thermal Throttling

High temperature seem to be an issue on the new Ryzen 7000 processors. We're pairing a Ryzen 9 7950X with a $10 stock cooler, a Noctua air-cooler and a 420 mm AIO to get a feel for what the differences are like in terms of °C, MHz and performance in both applications and games.

www.techpowerup.com

Check out this review and then let me know what you think.

AMD Ryzen 9 7950X3D Review - Best of Both Worlds

The Ryzen 9 7950X3D is the spearhead of the AMD Zen 4 X3D lineup. In our performance review we test AMD's new 16-core flagship with dozens of applications and 14 games at up to 4K, to see whether AMD can take the performance crown from Intel, how power consumption is affected, and what can be...

www.techpowerup.com

 

[Klemc]

Check out this review and then let me know what you think.

AMD Ryzen 9 7950X3D Review - Best of Both Worlds

The Ryzen 9 7950X3D is the spearhead of the AMD Zen 4 X3D lineup. In our performance review we test AMD's new 16-core flagship with dozens of applications and 14 games at up to 4K, to see whether AMD can take the performance crown from Intel, how power consumption is affected, and what can be...

www.techpowerup.com

I think :

7800X3D

 

[Daven]

I think :

7800X3D

Even better!

 

[3valatzy]

Avoid Ryzen in favor of what? Intel who is even hotter and uses more power?

Stay on previous gen AM4 Ryzens, or wait for faster next-gen 65W-95W Ryzens on AM5.

Oh, and wait till Lisa Su decides to offer normal IHS on top these CPUs.

 

[Daven]

Stay on previous gen AM4 Ryzens, or wait for faster next-gen 65W-95W Ryzens on AM5.

Oh, and wait till Lisa Su decides to offer normal IHS on top these CPUs.

I want the shape of my next IHS to be a unicorn humping a rainbow.

Anything else is an epic fail.

 

[Onasi]

You want a citation that computer enthusiasts don’t want next gen high end parts to be slower than last gen?

BTW the X3D parts are as efficient and low power as you can possibly ask for.

No one is asking for lower TDP for enthusiast CPUs

Uh, I was responding to this exact part of your statement. I have no idea where you got the “slower” part from. I assume, seeing how you brought up X3D yourself, that you are fully aware that there are ways of increasing performance without going overboard on power. Efficiency sweet spots are a thing. So… I have no idea what you are even arguing at this point.

 

[john_]

We don't know the rationale behind this inclusion, but AMD sure had a use case for it.

Probably this is an indication of when Zen5's first designs started. A period when that instruction was looking somewhat important and was still in Intel's included features.

 

[Jism]

The whole debate about too hot Ryzen CPU's - they are intended to run up or over 90 degrees.

So if it hits 90 degree's it's good; it's doing what it should. A 90 degree core is'nt going to melt down your room.

Its simply due to their performance target. When you let it it will do within scope of what it is capable of. Thats why you buy a performance cpu in the first place.

 

[EatingDirt]

Stay on previous gen AM4 Ryzens, or wait for faster next-gen 65W-95W Ryzens on AM5.

Oh, and wait till Lisa Su decides to offer normal IHS on top these CPUs.

You could simply buy a AM5 CPU and turn on ECO mode if you're concerned about heat(7950x has a 105w mode). It's a quick bios toggle. Intel is more slightly more complicated. The days of sub-105W Ryzen's are over, unless you're getting 6 core parts, unless we start seeing mixed Zen5c/Zen5 96xx/106xx series desktop parts.

IHS is there for compatibility to previous AM4 coolers. Now that it's established, I'd say it's basically guaranteed not to change until AM6.

No one is asking for lower TDP for enthusiast CPUs

Uh, I was responding to this exact part of your statement. I have no idea where you got the “slower” part from. I assume, seeing how you brought up X3D yourself, that you are fully aware that there are ways of increasing performance without going overboard on power. Efficiency sweet spots are a thing. So… I have no idea what you are even arguing at this point.

Efficiency sweet spots are a thing of the past. You're more than allowed to underclock your CPU to hit that sweet spot(AMD makes it easy with ECO mode), but Intel & AMD aren't going to sell lower power CPU capable of doing much more, for less money, like they did in the past.

 

[evernessince]

They must return to more convenient, "cool" and relatively quiet 95-125W TDPs.
170W CPUs requiring 360mm AIO is prohibitive.

This means that 9000 will be slower than 7000 because of the lower TDP (even if 10-15% IPC increase).

What a ridiculous - super hot CPUs, whiny small and hot M.2 PCIe 5.0 SSDs, super gigantic graphics cards.
All of them - no-go.

Ya do realize the 7800X3D exists right? It uses some 77w under an all core workload.

It is hot. My preference is to avoid it. Because of the heat.

All modern CPUs are designed to take advantage of thermal headroom. If you don't like it hot limit TJmax in the BIOS or enable Eco mode. This is a non-issue for people with even rudimentary computer experience.

 

[Random_User]

Great to see, that AMD expands their instructions set. However, does it has any reason, considering intel itself was hesitating to add AVX512, now just is clear for the more advanced AVX10. This at least has more reasoning, to not waste the money, for something more advanced, that might be already in the simultaneous development along with AVX512. However, these are just my layman guessings. I don't claim to be correct here.
But it requires of the reviews. This is in-line with the pre-Zen4 rummor mills.

I sincerely apoligize for derailling the thread, but:

They must return to more convenient, "cool" and relatively quiet 95-125W TDPs.
170W CPUs requiring 360mm AIO is prohibitive.

This means that 9000 will be slower than 7000 because of the lower TDP (even if 10-15% IPC increase).

What a ridiculous - super hot CPUs, whiny small and hot M.2 PCIe 5.0 SSDs, super gigantic graphics cards.
All of them - no-go.

Lol. What are you talking about? The Zen4 CPU will consume as much as user set it to consume. From what I've seen and read, the difference between various "ECO" modes and uncapped is not that big. Heck, one can put an intel shitty box cooler, and the CPU will envelop exactly to the cooling capacity. The throttling is not a problem, this is just the result of CPU being uncapped of it's max performance. And it won't get damaged, unless the reckless and lame "A...STek" motherboard vendor puts 1.45V on default, along with enormous current. Again, the CPU itself will just regulate it's performance, accordingly to it's cooling. Example. Another one.
Apply the same TDP limits as such that been used to Zen3, and it will perform the same, or even more efficiently.

And this isn't new stuff. There was an old video, might be Paul's Hardware, where the cooler on the editor's Threadripper has gone, and the clocks were just lowered. CPU was completely fine. And PC did everything it was thrown at.

You can set the 65, or even 35W limit to any modern Ryzen CPU, and will be cool and efficient. And it's just couple clicks. Some TPU users have shown, that intel "counterparts" can be efficient as well, but it's more pain to do so. However, out of the box, all last intel CPUs since 9K are just too hot and thirsty. They all just basically repeat that Pentium D moment, all over again.

Spoiler: Example

Now go and tell me, that the alternative, which you didn't provide, has much less powerconsumption.

But I completely agree, that CPU and GPU vendors, push their HW too far beyond it's sweet point. Just like it was with Vega, all HW, is better to set to UV, for just absolute majority of basic tasks most people do. And enthusiasts... well they know what they're doing, and what they want to achieve.
However, again, the Zen based CPUS, power envelop just goes accordingly to it's cooling capacities. There's no issues. They can be capped at e.g. 89W and still have the 90-95%-ish (don't quote me on that) of total performance. You've got the idea. With intel... I'm not really sure.

As about tiny M.2. Yes, they've deliberately chopped the lanes, and that's unacceptable. But go, show me M.2 5.0 on Z690, for example.

It is hot. My preference is to avoid it. Because of the heat.

View attachment 334222

AMD Ryzen 9 7950X Cooling Requirements & Thermal Throttling

High temperature seem to be an issue on the new Ryzen 7000 processors. We're pairing a Ryzen 9 7950X with a $10 stock cooler, a Noctua air-cooler and a 420 mm AIO to get a feel for what the differences are like in terms of °C, MHz and performance in both applications and games.

www.techpowerup.com

It's your preference, which I respect, and none can have judgegement for that.

Stay on previous gen AM4 Ryzens, or wait for faster next-gen 65W-95W Ryzens on AM5.

That's one of the possible alternates. The better one is 7800X3D. Since, Ze4 despite being slightly more powerhungry, it' is more powerefficient as well, and the only major difference compared to Zen3 is just, that Zen4 is basically uncapped, due to more rigid and powerful socket.
But if to consider the motherboard pricing, and their limited feature sets, then yeah, the AM4 boards have hugely better one. But then, the DDR4 RAM comes into play, which was more sensitive point for AM4 CPUs, then DDR5 to Zen4 ones. And considering it's stock shrinking, the amount of better RAM goes even pricier, and thus it's harder to find suitable kit. At this point, 64GB of DDR5 6000, can be a cheaper and better variant, considering DRAM cartel plans to rise prices for all RAM, for 20% each quarter, the DDR4 is a no go.

Oh, and wait till Lisa Su decides to offer normal IHS on top these CPUs.

Like the ones this?

I can get that IHS could be a lot thinner, and thus have better heat spread and dissipation. As much as it's less of an issue, when buying into new platform/PC.
But I also can get the reasoning behind this move, as, there's no need in change of cooler mount, as a result it is way less pain for the cooler manufacturers, to supply all the existing users the new mounting sets/kits, for basically the same TDP requirements. Contrary to the pointless change of socket specs, like several times for basically the same CPU and socket (115x drama), instead of using just same LGA1152/1156 straight from the beginning. Just because they could.
And everyone could see, how this cocket frequent change BS of "blue" team, ceased just when the competition appeared.

Spoiler

P.S.: If someone could gift me such "hot" and "powerthirsty" AMD Zen4 CPU like 7800X3D, or even 7950X, or even 8700G, I wouldn't complain at all.

 

[R-T-B]

A small correction: this instruction family was present only in Tiger Lake. Official support for it was removed from subsequent Intel processors.

Not in datacenter. But yes consumer parts are neutered.

 

[Minus Infinity]

Stop with the 10-15% IPC BS, every single leaker is saying 30%+