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AMD's Strix Point: Zen 5 Hits Mobile

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Re: AMD's Strix Point: Zen 5 Hits Mobile

#161

Post by hajile »

dzaima wrote: post #149
hajile wrote: post #147

Earlier quoted context omitted.

With 16 registers, you can't just avoid a register because it has a special use. Instead, you must work to efficiently schedule around that special use. Lack of special GPRs means you can rename with impunity (this will change slightly with the load/store pair extension). Having 31 truly GPR rather than 8 GPR+8 special GPR also gives a lot of freedom to compilers.

Function arguments and return values already are effectively special use, and should frequently be on par if not much more frequent than the couple x86 instructions with fixed registers. Both clang and gcc support calls having differing used calling conventions within one function, which ends up effectively exactly identical to fixed-register instructions (i.e. an x86 'imul r64' can be done via a pseudo-function wher…

Unlike x86, none of this is strictly necessary. As long as you put things back as expected, you may use all the registers however you like.

Re: AMD's Strix Point: Zen 5 Hits Mobile

#162

Post by Rinzler89 »

mkhalil wrote: post #154
automatic6131 wrote: post #153

Earlier quoted context omitted.

>I sit firm in my belief that the best thing Microsoft could do for their laptop ecosystem is to add support for a "max fan speed" slider somewhere prominent in the Windows UI Until then, there's https://github.com/Rem0o/FanControl.Releases

A closed source application for controlling one's fan...umm no thank you. I never will understand the reasoning behind why people are so afraid of releasing their source code. Looks like a weekend project; does he expect to make a living out of a weekend project?

>Looks like a weekend project;

Is that the best developer insult in your repertoire?

>does he expect to make a living out of a weekend project?

Trying to make money from writing SW is not illegal. The free market will decide.

>A closed source application for controlling one's fan...umm no thank you.

Well since you think it's only a weekend project, why don't you put your money where your mouth is and spend a weekend developing a FOSS fan control app if you need one?

Re: AMD's Strix Point: Zen 5 Hits Mobile

#163

Post by hajile »

kllrnohj wrote: post #160
aurareturn wrote: post #65

One of these has to be true (or both true): 1. ARM is inherently more efficient than x86 CPUs in most tasks 2. Nuvia and Apple are better CPU designers than AMD and Intel Here are results from Notebookcheck: Cinebench R24 ST perf/watt * M3: 12.7 points/watt * X Elite: 9.3 points/watt * AMD HX 370: 3.74 points/watt * AMD 8845HS: 3.1 points/watt * Intel 155H: 3.1 points/watt In ST, Apple is 3.4x more efficient than Zen…

> 1. ARM is inherently more efficient than x86 CPUs in most tasks I'm not sure how you're reaching the conclusion of "most tasks" when Cinebench R24 is the only test you used because R23, which doesn't agree, was rejected for hand-wavey nebulous reasons, and nothing else was tested. R24 is hardly a representative workload of "most tasks" nor is it claiming/trying to be.

Anandtech shows[0] that M3 is massively ahead in integer performance, but slightly behind in float performance on Spec 2017.

Integer workloads are by far the most common, but they tend to not scale to multiple cores very well. Most workloads that scale well across cores also benefit from big FP/SIMD units too.

Put another way, the real issue with R24 is that it makes HX370 look better than it would look in more normal consumer workloads.

[0] https://www.anandtech.com/show/21485/the-amd-ryzen-ai-hx-370...

Re: AMD's Strix Point: Zen 5 Hits Mobile

#164

Post by sandywaffles »

arnaudsm wrote: post #7
sm_1024 wrote: post #2

IMO, the most interesting thing about this line is the battery life---within an hour of MBP3 and within 2 hours of Asus's Qualcomm. Making it comparable to ARM architectures. Which is a little surprising because ARM is commonly believed to be much more power efficient than x86. [1] https://youtu.be/Z8WKR0VHfJw?si=A7zbFY2lsDa8iVQN&t=277

ARM got a lot of hype since the release of the M1, but most users only compared it to the terrible Intel MBPs. Ryzen mobile has been consistently close to Apple silicon perf/watt for 5 years. But got little press coverage. Hype can be really decorrelated from real world performance.

I think that's because all the press talks about actual battery life per laptop and the Apple Silicone laptops ship with literally double the size battery of any AMD based laptop without a discrete GPU. So while the efficiency may be close, actually perceived battery life of the Mac will he more than double when you also consider the priority Apple puts into their power control combined with a larger overall battery.

Re: AMD's Strix Point: Zen 5 Hits Mobile

#165

Post by aurareturn »

kllrnohj wrote: post #160
aurareturn wrote: post #65

One of these has to be true (or both true): 1. ARM is inherently more efficient than x86 CPUs in most tasks 2. Nuvia and Apple are better CPU designers than AMD and Intel Here are results from Notebookcheck: Cinebench R24 ST perf/watt * M3: 12.7 points/watt * X Elite: 9.3 points/watt * AMD HX 370: 3.74 points/watt * AMD 8845HS: 3.1 points/watt * Intel 155H: 3.1 points/watt In ST, Apple is 3.4x more efficient than Zen…

> 1. ARM is inherently more efficient than x86 CPUs in most tasks I'm not sure how you're reaching the conclusion of "most tasks" when Cinebench R24 is the only test you used because R23, which doesn't agree, was rejected for hand-wavey nebulous reasons, and nothing else was tested. R24 is hardly a representative workload of "most tasks" nor is it claiming/trying to be.

>I'm not sure how you're reaching the conclusion of "most tasks" when Cinebench R24 is the only test you used because R23, which doesn't agree, was rejected for hand-wavey nebulous reasons, and nothing else was tested.

There are no hand-wavey nebulous reasons.

Cinebench R23 uses Intel Embree engine, which is hand optimized for x86 CPUs. That's why x86 CPUs look far better than ARM CPUs in it.

If there is an application that is purely hand optimized for ARM, and then compiled for x86, do you think it's fair to use it to compare the two architectures?

SPEC & GB6 mostly agrees with Cinebench 2024.

Re: AMD's Strix Point: Zen 5 Hits Mobile

#166

Post by 999900000999 »

sedatk wrote: post #151
999900000999 wrote: post #30

Earlier quoted context omitted.

I have a 365 AMD laptop. The battery is great if your doing very light stuff, Call of Duty takes it's battery down to 3 hours. Macs don't really support higher end games, so I can't directly compare to my M1 Air.

How does “great” translate to hours?

This is really tricky.

The OEMs will use ever trick possible and do something like open GMAIL to claim 10 hours, but given my typical use I average 5 to 6. I make music using a software called Maschine.

It's a massive step up over my old( still working just very heavy) Lenovo Legion 2020, which would last about 2 hours given the same usage.

This is all subjective at the end of the day. If none of your applications actually work since your on ARM Windows of course you'll have higher battery life.

Re: AMD's Strix Point: Zen 5 Hits Mobile

#167

Post by neonsunset »

clamchowder wrote: post #71
hajile wrote: post #36

Earlier quoted context omitted.

Clam makes some serious technical mistakes in that article and some info is outdated. 1. His claim that "ARM decoder is complex too" was wrong at the time (M1 being an obvious example) and has been proven more wrong since publication. ARM dropped the uop cache as soon as they dropped support for their very CISC-y 32-bit catastrophe. They bragged that this coincided with a whopping 75% reduction in decoder size for th…

Some notes: 1. Consider M1's 8-wide decoder hit the 5+ GHz clock speeds that Intel Golden Cove's decoder can. More complex logic with more delays is harder to clock up. Of course M1 may be held back by another critical path, but it's interesting that no one has managed to get a 8-wide Arm decoder running at the clock speeds that Zen 3/4 and Golden Cove can. A715's slides say the L1 icache gains uop cache features inc…

> Not sure what you mean by "peephole heuristic optimizations"

Post-emit or within-emit stage optimization where a sequence of instructions is replaced with a more efficient shorter variant.

Think replacing pairs of ldr and str with ldp and stp, changing ldr and increment with ldr with post-index addressing mode, replacing address calculation before atomic load with atomic load with addressing mode (I think it was in ARMv8.3-a?).

The "heuristic" here might be possibly related to additional analysis when doing such optimizations.

For example, previously mentioned ldr, ldr -> ldp (or stp) optimization is not always a win. During work on .NET 9, there was a change[0] that improved load and store reordering to make it more likely that simple consecutive loads and stores are merged on ARM64. However, this change caused regressions in various hot paths because, for example, previously matched ldr w0, [addr], ldr w1, [addr+4] -> modify w0 -> str w0, [addr] pair got replaced with ldp w0, w1, [add] -> modify w0, str w0 [addr].

Turns out this kind of merging defeated store forwarding on Firestorm (and newer) as well as other ARM cores. The regression was subsequently fixed[1], but I think the parent comment author may have had scenarios like these in mind.

[0]: https://github.com/dotnet/runtime/pull/92768

[1]: https://github.com/dotnet/runtime/pull/105695

Re: AMD's Strix Point: Zen 5 Hits Mobile

#168

Post by wmf »

moffkalast wrote: post #111
hajile wrote: post #44

Earlier quoted context omitted.

I think there's a lot of hope for a Strix Halo mini-PC. We currently have 7840HS+6650M with two massive heatsinks just barely coming in at what you would consider a large mini-PC rather than a SFFPC. Just one chip cuts the heatsink demand in half. The cores should be faster and it moves from 28CU up to 40CU and from RDNA2 to RDNA3.5. As long as the cross-core-complex latency isn't as bad as the HX370, I think it coul…

Hell I'd settle for a Z1 SBC or even mini PC. They can't seem to keep up with demand for these new chips to put them into any sort of products that don't have complete mass appeal. It's impossible to find one that's not in a handheld gaming console. I doubt they'll even make enough of the Halo to cover laptops.

Z1 is basically the same as 8840U which you can find.

Re: AMD's Strix Point: Zen 5 Hits Mobile

#169

Post by kllrnohj »

hajile wrote: post #163
kllrnohj wrote: post #160

Earlier quoted context omitted.

> 1. ARM is inherently more efficient than x86 CPUs in most tasks I'm not sure how you're reaching the conclusion of "most tasks" when Cinebench R24 is the only test you used because R23, which doesn't agree, was rejected for hand-wavey nebulous reasons, and nothing else was tested. R24 is hardly a representative workload of "most tasks" nor is it claiming/trying to be.

Anandtech shows[0] that M3 is massively ahead in integer performance, but slightly behind in float performance on Spec 2017. Integer workloads are by far the most common, but they tend to not scale to multiple cores very well. Most workloads that scale well across cores also benefit from big FP/SIMD units too. Put another way, the real issue with R24 is that it makes HX370 look better than it would look in more norma…

> that M3 is massively ahead in integer performance

The M3 is certainly an impressive chip, but note that it's only massively ahead in some of the int tests. It's not a consistent gap.

> Integer workloads are by far the most common, but they tend to not scale to multiple cores very well.

The HX370 does better than the Me in specint MT though.

But regardless the anandtech results paint a much closer picture than the single R24 results that GP used as the basis of the efficiency thesis.

Re: AMD's Strix Point: Zen 5 Hits Mobile

#170

Post by ThatMedicIsASpy »

AnthonyMouse wrote: post #119
rafaelmn wrote: post #76

Earlier quoted context omitted.

MacBook Air is thin and fanless, so it can be done.

"Thin and fanless" aren't that hard, just use any low power CPU. But then people also want fast. Apple does this by buying out TSMC's capacity for the latest process nodes and then taking the performance/efficiency trade off in favor of efficiency, so they get something with similar performance and lower power consumption. But then they charge you $400 for $50 worth of RAM and solder it so you can't upgrade it yourse…

Don't run Windows and you don't need fast. Unfortunately Linux on notebooks is always a dice roll of random features (cam, fingerprint, ..) not working.

There is a lot of older hardware running like crap because Windows just bloats up.

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