Question AMD Phoenix/Zen 4 APU Speculation and Discussion

[uzzi38]

I can finally make this thread.

https://twitter.com/x/status/1519669375283957760

Phoenix is indeed RDNA3. My advice to everyone: treat the old APU rumours as being out of date.

 

[SteinFG]

Is it possible that reduced memory latency on the APU may overcome the PCIe bandwidth loss, if there is one?

Unrelated parts, the amount of data passing between CPU and GPU won't change from lower memory latency on RAM.

 

[MrTeal]

The weirder thing I wanted to mention is crippled PCIe. small phoenix has 14 PCIe lanes, 4 are used for the GPU, 4 for the chipset, 4 for the primary NVMe, and the remaining 2 is for secondary NVMe. There should be some test done with a 4070 and 8500G/8600G

More testing is always better, but in TPU's 4090 PCIe scaling article they found at PCIe2.0 x16 (same BW as 4.0 x4) they still got 92% of x16 4.0 performance at 4k and 94% at 1080p and 1440p.

x4 4.0 was an issue in something like the 6500XT because it was reasonable to assume that would end up in systems with PCIe 3.0 or even a 2.0 Sandy Bridge system. Not sure it's really a huge issue here as you're not going to see the same thing in reverse; x4 isn't ideal buy you're probably not pairing a 8500G with a 4090 or even a 4070. Worst case would probably be pairing it with a 2080 Ti and being limited to x4 3.0, but TPU's testing showed that to be about a 5-10% performance loss vs x16 3.0.

Lots of doom and gloom about Phoenix 2, but a lot of it seems a little over the top.

 

[gdansk]

The doom of Phoenix 2 is that it still isn't small enough despite all the sacrifices.

 

[MrTeal]

The doom of Phoenix 2 is that it still isn't small enough despite all the sacrifices.

Well, that and the price. Still, I'm talking more about stuff like this.

If you're planning out a system with a 4090 and a Samsung 990 Pro as a secondary drive, a 8500G might not be the CPU choice for you regardless of IO.

 

[Shivansps]

Once you get to 2.0 x16 levels of bandwidth you need to do more than gaming to see the diference. Like gaming and recording using gpu hardware acceleration, that would be bad, as well as having the monitor plugged into the IGPU and using the dgpu by copying back frames only for games that actually need a dgpu.

Thats the least of the problems of Phoenix 2, but something to keep in mind too

The doom of Phoenix 2 is that it still isn't small enough despite all the sacrifices.

Exactly, Phoenix 2 is a SoC that seems seems to be developed for a very wide range of roles and in doing so it ends to have tons of extra hardware at the same time important stuff got cut off. Like it is a handheld SoC? a low end desktop soc? a low end notebook soc? Is this SoC to be labeled as a Ryzen or a Athlon? It is intended to compite with the NXXX or the mainline Core IX?

Not sure, it ends up having 6 cores, when Phoenix 1 has 8, it really needs 6 cores? Why it has AVX512? it really needs to support 4 displays?, usb 4? and so on...

Full specs are out

https://www.amd.com/en/product/14086

Single Channel too

 

[SteinFG]

Once you get to 2.0 x16 levels of bandwidth you need to do more than gaming to see the diference. Like gaming and recording using gpu hardware acceleration, that would be bad, as well as having the monitor plugged into the IGPU and using the dgpu by copying back frames only for games that actually need a dgpu.

Streaming assets (direct storage) might cripple it.

0Exactly, Phoenix 2 is a SoC that seems seems to be developed for a very wide range of roles and in doing so it ends to have tons of extra hardware. Like it is a handheld SoC? a low end desktop soc? a low end notebook soc? Is this SoC to be labeled as a Ryzen or a Athlon?

Ryzen, not athlon. Athlon is mendocino now (and sonoma after that).

Why it has AVX512? it really needs to support 4 displays?, usb 4? and so on...

It needs to support 4 Displays because AM5 boards have up to 4 display outputs. USB4 isn't necessary though.

Single Channel too

That's a typo, it's dual channel. check 8300G/7440U/8440U/8540U, all dual channel, all phoenix2

 

[gdansk]

It is dual channel (well quad actually) based on die shot.

 

[Shivansps]

Yeah they fixed it now

 

[Shivansps]

Ryzen, not athlon. Athlon is mendocino now (and sonoma after that).

Mendocino is old now and ranged from Athlon to Ryzen 5, it looks like the predecesor to Phoenix 2, but its not. Atleast not directly as it is LPDDR5 only.

 

[SteinFG]

Mendocino is old now and ranged from Athlon to Ryzen 5, it looks like the predecesor to Phoenix 2, but its not. Atleast not directly as it is LPDDR5 only.

Mendocino is a successor of Pollock (also 1-channel), but pollock was so weak they didn't even name it as athlon, just AMD 3015e processor.
Mendocino's successor will also have single channel of LPDDR (sonoma valley, 2025-2026)

 

[moinmoin]

Mendocino's successor will also have single channel of LPDDR (sonoma valley, 2025-2026)

Sonoma Valley is said to contain only Zen 5c cores, isn't it? Will be very interesting to see how these will fare in client space.

 

[Shivansps]

What would be Phoenix 2 predecedor? Dali/Raven2? there are so many variations that it is hard to keep track of all of them.

Im petty sure there will be a Athlon based on it down the line, something like a 4/4 Athlon with 2/3 CUs they will need to hardvest bad igps eventually and the 8300G is still full igpu.

 

[eek2121]

Streaming assets (direct storage) might cripple it.

Ryzen, not athlon. Athlon is mendocino now (and sonoma after that).

It needs to support 4 Displays because AM5 boards have up to 4 display outputs. USB4 isn't necessary though.

That's a typo, it's dual channel. check 8300G/7440U/8440U/8540U, all dual channel, all phoenix2

He's wrong at any rate. The 4090 takes a pretty significant hit at higher resolutions on PCIE 2.x

Well, that and the price. Still, I'm talking more about stuff like this.
View attachment 92000
If you're planning out a system with a 4090 and a Samsung 990 Pro as a secondary drive, a 8500G might not be the CPU choice for you regardless of IO.

Why would you do that? That is such an unbalanced config. APUs aren't for high end gaming.

 

[moinmoin]

What would be Phoenix 2 predecedor? Dali/Raven2?

What's the predecessor to Siena? The answer is: there isn't one. With the Zen 4 gen AMD vastly expanded its product portfolio, adding more different platforms and more distinct dies. Phoenix 2 is one example of that.

 

[SteinFG]

What would be Phoenix 2 predecedor? Dali/Raven2? there are so many variations that it is hard to keep track of all of them.

Yep, also, Dali is Raven 2, interchangeable names. Although the only common thing between Dali and Phonix2 is a weak GPU and Dual-Channel RAM, as cores got tripled, IO got much beefier.

It was like this: Dali (athlon and R3) < Picasso (R3, R5) < Renoir/Cezanne (R5, R7, R9).

Now it's going to be: Mendocino (Athlon, R3) < Phoenix2 (R3, R5) < Phoenix1 (R5, R7, R9)

Edit: 7520U shouldn't count, it's wild that they named their lowest-end die as Ryzen 5, hope it doesn't repeat again

 

[Shivansps]

What's the predecessor to Siena? The answer is: there isn't one. With the Zen 4 gen AMD vastly expanded its product portfolio, adding more different platforms and more distinct dies. Phoenix 2 is one example of that.

I dont see why there is no much problem to say that Phoenix 2 is Raven2/Dali successor, Raven2/Dali was designed as a "half-raven" with a 1/4 igpu to cover the low end to save money (instead of selling cut down ravens) and thats is very very close to what Phoenix 2 is compared to Phoenix 1.

Yep, also, Dali is Raven 2, interchangeable names. Although the only common thing between Dali and Phonix2 is a weak GPU and Dual-Channel RAM, as cores got tripled, IO got much beefier.

It was like this: Dali (athlon and R3) < Picasso (R3, R5) < Renoir/Cezanne (R5, R7, R9).

Now it's going to be: Mendocino (Athlon, R3) < Phoenix2 (R3, R5) < Phoenix1 (R5, R7, R9)

Edit: 7520U shouldn't count, it's wild that they named their lowest-end die as Ryzen 5, hope it doesn't repeat again

Mendocino is AMD ADL-N, 4 lanes PCIe, 64 bits LPDDR5 only... There is no way to compare that to Dali/Raven2 that was still a pure laptop/notebook soc like Phoenix 2 is.

 

[moinmoin]

I dont see why there is no much problem to say that Phoenix 2 is Raven2/Dali successor, Raven2/Dali was designed as a "half-raven" with a 1/4 igpu to cover the low end to save money (instead of selling cut down ravens) and thats is very very close to what Phoenix 2 is compared to Phoenix 1.


Mendocino is AMD ADL-N, 4 lanes PCIe, 64 bits LPDDR5 only... There is no way to compare that to Dali/Raven2 that was still a pure laptop/notebook soc like Phoenix 2 is.

Starting with Renoir APUs moved upward spec wise (8 vs 4 cores). While the approach seems similar, the markets are different. Raven2/Dali/Pollock covered the lowest market, that's succeeded by Mendocino and Sonoma Valley. Phoenix 2 market wise is a new in-between level, not as low as Mendocino but also not Phoenix. It's replacing still existing old APUs like Picasso and lower end Renoir and Cezanne SKUs.

 

[Shivansps]

Starting with Renoir APUs moved upward spec wise (8 vs 4 cores). While the approach seems similar, the markets are different. Raven2/Dali/Pollock covered the lowest market, that's succeeded by Mendocino and Sonoma Valley. Phoenix 2 market wise is a new in-between level, not as low as Mendocino but also not Phoenix. It's replacing still existing old APUs like Picasso and lower end Renoir and Cezanne SKUs.

There is no way that Mendocino can replace all the market Dali had, there is a severe reduction in pcie lanes and memory is limited to soldered ram.
Maybe the reason here is that Dali was used for a wide wide market range, going from AM4 desktop all the way down to SBC embedded. Part of that market goes to Phoenix 2 that is designed with the same idea as Dali was, a cut down version of the big APU die to save money on the lower end.

 

[SteinFG]

There is no way that Mendocino can replace all the market Dali had, there is a severe reduction in pcie lanes and memory is limited to soldered ram.
Maybe the reason here is that Dali was used for a wide wide market range, going from AM4 desktop all the way down to SBC embedded. Part of that market goes to Phoenix 2 that is designed with the same idea as Dali was, a cut down version of the big APU die to save money on the lower end.

PCIe doesn't matter on <$400 laptops, used only for storage. Memory limitation is a non-issue too. Tons of laptops sold with soldered memory and majority doesn't care.

The only market mendocino lost is desktop, but even there dali/raven2 was limited to one 50$ CPU (3000G).

The design principle of Raven2 and Phoenix2 may be the same (take Raven and shrink it, Take Phoenix and shrink it), costs are different. Raven was $150 cpu shrunk to a 2-core $50 cpu, while Phoenix is a $330 cpu shrunk to 6-core $180 cpu.

 

[Asterox]

Well, that and the price. Still, I'm talking more about stuff like this.
View attachment 92000
If you're planning out a system with a RTX 4090 and a Samsung 990 Pro as a secondary drive, a 8500G might not be the CPU choice for you regardless of IO.

It's unimaginable to me, that anyone sane or sober would pair red(2000$ GPU)with any current new 65W APU or CPU.In practice it doesn't happen, let's be realistic because it doesn't make any sense.

Pair a fast expensive SSD(PCIe 3.0 or 4.0)with any processor, yes why not if you want a fast system.An ultra-fast SSD is not needed for 90% of users. But if you really want to(even though you are wasting money unnecessarily), that's ok you're not crazy or drunk.

Why are we even discussing this or finding it as a potential flaw, with 65W APU intended for a HTPC PC or a cheap iGPU gaming PC, or say paired with RX 6600/RX 6600XT or RX 7600/RX 7600XT as an example.

 

[MrTeal]

He's wrong at any rate. The 4090 takes a pretty significant hit at higher resolutions on PCIE 2.x


Why would you do that? That is such an unbalanced config. APUs aren't for high end gaming.

You wouldn't, that's the point. Having four lanes for a potential dGPU and only two lanes for a second m.2 (though four for the primary) would be a big limitation in a 7800X3D. You shouldn't be using a 8500G in a system like that though. If you're planning dGPU you should be picking a 7600 instead of this, and even if you get a system with a 8500G using the iGPU but decide to upgrade later you're probably looking at a lower end dGPU. Likewise your system would probably come with a single m.2 in the x4 lane, even if you upgrade to a new fast 4.0 one and want to keep the old one, your big new one should be going in the x4 slot.

Yeah it'd be nice if Phoenix 2 had more lanes, but all the talk about it being crippled is overblown since it's the wrong CPU choice for pretty much any configuration where they would be a limitation.

 

[Thibsie]

You wouldn't, that's the point. Having four lanes for a potential dGPU and only two lanes for a second m.2 (though four for the primary) would be a big limitation in a 7800X3D. You shouldn't be using a 8500G in a system like that though. If you're planning dGPU you should be picking a 7600 instead of this, and even if you get a system with a 8500G using the iGPU but decide to upgrade later you're probably looking at a lower end dGPU. Likewise your system would probably come with a single m.2 in the x4 lane, even if you upgrade to a new fast 4.0 one and want to keep the old one, your big new one should be going in the x4 slot.

Yeah it'd be nice if Phoenix 2 had more lanes, but all the talk about it being crippled is overblown since it's the wrong CPU choice for pretty much any configuration where they would be a limitation.

Yeah but it generated clicks, you know 🤷

 

[Shivansps]

You wouldn't, that's the point. Having four lanes for a potential dGPU and only two lanes for a second m.2 (though four for the primary) would be a big limitation in a 7800X3D. You shouldn't be using a 8500G in a system like that though. If you're planning dGPU you should be picking a 7600 instead of this, and even if you get a system with a 8500G using the iGPU but decide to upgrade later you're probably looking at a lower end dGPU. Likewise your system would probably come with a single m.2 in the x4 lane, even if you upgrade to a new fast 4.0 one and want to keep the old one, your big new one should be going in the x4 slot.

Yeah it'd be nice if Phoenix 2 had more lanes, but all the talk about it being crippled is overblown since it's the wrong CPU choice for pretty much any configuration where they would be a limitation.

As i said it i think most of the problems with Phoenix 2 is that they did the wrong cutdowns, like they made it a 6 core when phoenix 1 already covers that. It should have been a 2+2 whiout AVX512. It is a 6 core but the igpu is too weak to take advantage of that and the pcie is limited. But they kinda needed the 6 cores to charge over $150 for it.

Now, forget the RTX 4090, if you do something that hits the bandwidth limit you can hit it with almost any gpu. In fact the 4090 is less likely to hit the limit due to the huge amount of VRAM.

And dont say "do work with it"... the leaked MT perf was just bad, if you want to "do work" you are probably better off with something like the 7600.

 

[Abwx]

As i said it i think most of the problems with Phoenix 2 is that they did the wrong cutdowns, like they made it a 6 core when phoenix 1 already covers that. It should have been a 2+2 whiout AVX512.

With a 6C die they can still harvest faulty chips that have 4 functional cores, with a 4C die this would be 2C/4T as cut down chips, so they took the good decision.

 

[Zepp]

...pollock was so weak they didn't even name it as athlon, just AMD 3015e processor.

I'm pretty sure the 3015e holds the title of weakest of all Ryzen based processor

I had experience with it's ever so slightly better brother the 3020e (only real difference is 300Mhz higher boost) in a bargain laptop.

I always wondered if SMT being disabled on these was to keep it in the 6w range, a physical defect, or just artificial segmentation?

to me it's a ridiculous notion to release a 2 thread CPU for general purpose consumer hardware in 2020, even if it was zen3, but these were zen1 and single channel... smh