No longer care. Think what you will.
No problem - it's not me who lacks a fundamental understanding of power/clock scaling in modern CPUs, yet insists on debating this very thing. You are arguing that the 4800U and the 4800H will perform the same. They will not. If they did, why does the 4800H exist at all? And in your thinking, what does the Base Clock spec mean?
Which iGPU is saving power the 45W APU one? Because the APU is rated 45W so how is that saving power in comparison to 15W APU?
The not-fully-enabled and lower-clocked iGPU on the highest-end 45W APU is saving power compared to what we know to be the largest/most powerful iGPU possible in this silicon. I never said 45W APUs save power compared to 15W APUs - that statement is an invention of your own. Trying to rephrase for clarity: there
could have been a higher end 45W APU iGPU - but there isn't. The reason for this is - as I've been trying to explain to you this entire time - that a) the added performance isn't necessary, and b) fully enabling the iGPU would waste power for no good reason. This was the question you first posed - "Why is there no 8CU 45W APU when there is an 8CU 15W APU?" - which I've been trying to answer for you.
And this. in red mine to point out with what i have problem.
Nothing is attached the dGPU is not powered by the 45W APU.
...the dGPU is attached (over PCIe), otherwise it wouldn't work. I never said it was
powered by the APU, nor that it in any way shared the APU's power budget. I only said that increasing the power allotment to the CPU part of the APU allows it to run faster, which serves to improve gaming and mixed-workload performance in addition to pure CPU performance as the CPU can run faster than if the iGPU was wasting unnecessary power. It stands to reason that a faster CPU improves performance, no? Hence, saving power on the iGPU, allotting more power to the CPU, thus increases performance. It won't increase performance in a fully GPU-limited scenario, but it
will increase performance in any CPU-limited scenario.
How do you sacrifice anything here? The 15W APU is rated for the entire unit not individually CPU or iGPU. It simply uses less power but sustains 4.2Ghz clock with iGPU that has higher frequency and more CUs.
...You are sacrificing potential battery life that a lower-spec iGPU would give you. Also, no, a 15W chip will not sustain 4.2GHz beyond a relatively short boost window, and certainly not while the iGPU is being heavily loaded. Read any reviews of the same laptop with a high-spec and low-spec CPU in the same series (Ryzen 7 vs. 5, i7 vs. i5/i3, whatever) - the lower spec version will always have better battery life. So there are definitely sacrifices made to reach the ultimate 15W-class performance.
For example: The Core i7 9850H has 6 cores, 12 threads, a 45W TDP and a max boost clock of 4.6GHz. The Core i7-10710U has 6 cores, 12 threads, a 15W TDP and a max boost clock of 4.7 GHz*. Yet
the 9850H can sustain Cinebench R15 scores of ~1100 given sufficient cooling (there's a link there) while the 10710U even in it's 25W cTDP-up mode in the Dell XPS 13 fluctuates between ~820 and ~950, never quite flattening out. I couldn't find a comparable review of the 10710U in 15W mode, sadly (the
MSI Prestige 14 pushes it to ~30W, and the
Prestige 15 goes even further, again in-line links in both of the names). In other words, there's no correlation between boost clock specs and sustained performance, particularly across different TDP classes. And a higher TDP especially improves sustained performance.
*Yes, these chips are of different generations and marginally different silicon, but both are made on the same process node (Intel 14nm++), are based on the same architecture (Skylake) and the biggest differences in silicon are the number of PCIe lanes and memory support - they even have the same amount of cache.
This one has 45W rated TDP as an APU. This is how much power it uses despite what the iGPU configuration is. So how is it saving power in comparison to 15W APU with actually better APU? This is not about saving power for me. It is about silicon quality. Same performance lower TDP for the 15W makes it perfect for ultrabooks (for example). But it doesn't mean it can't have a dGPU. it can, that would mean the overall laptop power will be lower if you compare it to 45W APU giving that all other components are the same.
I never said 15W APUs
can't have dGPUs - I very specifically said that they mostly won't. That's a substantial difference, no? Beyond that, you keep making this 15W-to-45W comparison, which is not what I'm arguing at all. What I'm saying is that a 45W APU with a slightly toned-down iGPU benefits from this by having better battery life in low loads than a similar 45W APU with a fully-enabled and higher clocked iGPU would have. 15W APUs will still have better battery life by virtue of having much stricter power limits. You are misreading me and turning this into a straw man argument. Please stop.
Put very simply:
A 45W APU with 7 CUs would have better battery life in normal desktop usage than a 45W APU with 8 CUs given that everything else (clock speeds etc.) are equal. I never compared this to 15W APUs.
Silicon quality can do a lot, but it can't make a 15W APU match the sustained performance of a 45W one. They are in different performance classes. That does not mean that the 45W will be 3x the performance, obviously, as clock speeds don't scale linearly with power draw, but the 45W chip will be able to boost higher for longer and thus perform better overall.
I don't have problem understanding. I comprehend everything you said correctly
No. You don't. I have read your responses, and they make no sense whatsoever based on what I'm saying, and you are continuing to attribute statements and claims to me which I have not made. So no, it is quite impossible that you are understanding what I'm saying. I have pointed out a number of clear-cut and relatively simple misunderstandings both here and previously, but you have handily skipped over every single one of these clarifiations. I'm not going to speculate as to why, but this is a direct hindrance to actually understanding each other, and this is entirely on you.
but your way of expressing yourself leaves unsatisfying urge for me to tell you be more specific because what you say is not what you mean and vice versa. At least.
Wait, I'm not saying what I mean? Are you a mind reader? Beyond that, you're welcome to ask me for any clarification you might want, but you don't tend to do that, but rather seem to prefer paraphrasing what I'm saying in fundamentally mistaken ways and then arguing against it.
Yes you didn't say 12c or 16c. I said it assuming you were talking about R9 (analogy to Ryzen 9 which is 12 and above) . next time say you are talking about iGPU and there will be no problem.
Why should that be necessary? We're talking about mobile APUs. An APU has an iGPU - that's what makes it an APU and not a CPU. You're the one that made a significant logical leap here, in assuming that an R9 in this context (that context being mobile, APU-centric, reated to the specific piece of silicon that underpins the 4000-series APUs) would somehow be a >8c
CPU and not an
APU. I never did or said anything to indicate that I meant anything more than a higher-binned and higher-clocked SKU of the current silicon.
BTW, the fully enabled iGPU is the 15W 4800U. Unless there's more than 8CU?
Yes, it is fully enabled (as far as we know, at least). As I have been saying the whole time: we don't have a
fully enabled 45W APU. You are somehow arguing against that by saying "But we do, it's the 15W 4800U!" Which, to be clear, is not a 45W APU. Are we really going to keep going in circles here? A 15W APU is not a 45W APU.
Misquoted? it is exactly what you said.
here.
AMD commented directly on this, saying that OEMs don't seem interested in making dGPU-less laptops with the 45W chips. Slimming down the iGPU thus makes sense as its role then becomes "power saving GPU" rather than "maximum performance iGPU".
Yes, that is what I said. But then you paraphrased this into the following:
You said it here. OEMs' are not interested in making 45W chips because they would rather focus on power saving GPUs. Slimming down to use less power?
Which is not at all the same. Seriously, please read the two sentences, one after the other, and tell me if they say the same thing. You're saying I said "OEMs are not interested in making 45W chips..." while what I said was "OEMs don't seem interested in making dGPU-less laptops with the 45W chips". You see how these sentences say fundamentally different things, right?
You then asked for a source, which I provided:
Asking for sourcing is fine, and I should probably have provided it right away. Then again, asking about it is probably what you should have done, rather than putting words in my mouth. Here, from
AnandTech:
The link is in "AnandTech" directly before where I then quoted their article. Sorry if you missed that, but putting source links in attributions before quotes is quite standard practice across the internet.
Though you mentioned AMD but there is no link so.....
See above. There is most definitely a link. And even a direct quote from the article! It sounds like you didn't actually read my post ...
I think you mean power balance/draw between the iGPU and the CPU. When the iGPU is not being used the CPU get's all the power?
Yes, that balance is the point of this entire argument. But no, the CPU does not get
all the power when the iGPU is not in use, as the iGPU is still running the display controller and performing various other (non-3D/compute/rendering) tasks when the dGPU is active. Unless the iGPU's compute units are power gated (which they haven't been in designs up until now, at least), they will still be consuming
some power - which the CPU then can't use. Which lowers CPU performance compared to how high it would then be with a smaller iGPU.
Let's illustrate this. While these numbers are made up for this example, they shouldn't be unreasonably far from reality.
The APU has a 45W total power budget for sustained loads. Of this, it's not unreasonable to think that 5-10W goes to SoC/non- CPU core power dependent on the workload even when the iGPU is idle. Why?
-the 3D/compute portion of the iGPU is idle, but likely not power gated, just clock gated. This means it's
on, just running at a very slow speed, thus still consuming power.
-the non-compute portion of the iGPU is (partially) active, running the display output(s) and other fundamental functionality.
-other SoC tasks use the APU's power budget, so memory controllers, SATA, PCIe, Infinity Fabric, etc. all consume some power. Communicating with a dGPU over PCIe consumes power. Communicating with an SSD over PCIe or SATA consumes power (I'm not talking about the SSD's power consumption, which is separate and unrelated, but PCIe and SATA link power, which comes from the APU's power budget).
So, that means that the CPU is at all times unable to use a certain portion of the APU's power budget. It thus stands to reason that
any reduction to the above power draws will allow the CPU cores to draw
more power within the 45W max budget, and thus perform better. The difference might not be a lot, but it's there.
Now, which of the above points can be changed? PCIe link power can't be changed, as you'd either need to disable your dGPU or SSD, which ... well, wouldn't let you do much with your PC. Display controller duties and other fundamental I/O that the iGPU handles can't be disabled either, as ... well, you wouldn't have a working display. So the only thing that
can scale down is the idle iGPU. Disabling CUs in this
directly correlates to a drop in idle power draw, as disabled CUs don't use power.
So: disabling a CU or two in a 45W APU might therefore allow the CPU cores to perform ever-so-slightly
faster than if the same APU had all CUs enabled. As an added benefit, this partially disabled iGPU would consume less power when active compared to a fully enabled version when in use, improving battery life when the dGPU isn't in use.
You have misspoken using power instead of performance. It didn't make sense "CPU power is useful and GPU power isn't. and we move on to your last sentence which makes even more confusion but I think I get what you are trying to say. I hope, considering our conversation history, I'm not so sure now.
You're right here, I said "power" in some places where I meant "performance". Sorry about that, and it's a useful clarification.
I'd love to but I'm tired of trying to understand what you wrote or what you meant. Honestly, just let it go and move on.
That's a massive cop-out if I ever saw one. You're entirely welcome to bow out of the discussion any time you like, but don't project this onto me.