Rumor: Intel to Introduce Big.Little Architecture for Desktop With Alder Lake-S, New LGA 1700 Socket

[londiste]

You are talking about different things. AMD can clock their cores in 25MHz increments and very-very quickly. However, there is currently something in the chiplet architecture that cannot be clocked and/or powered down sufficiently, increasing the idle power consumption of Ryzen 3000 CPUs. TPU's graph is one of the better results, the difference (between Zen2 and Zen+) in most reviews tends to be bigger.

 

[ARF]

And here is the result of that: at least 20% more idle usage, in this example.

This is the system power consumption which includes mainboard, X570 chipset, SSD, GPU, and so on.
AMD's GPUs can idle at as low as 20-30 MHz. AMD has always been known for not working optimally with the frequencies, they just need time to adjust everything properly.
Example, HD 4890 didn't lower its memory clocks and they always run at 100%.

 

[Vayra86]

This is the system power consumption which includes mainboard, X570 chipset, SSD, GPU, and so on.
AMD's GPUs can idle at as low as 20-30 MHz. AMD has always been known for not working optimally with the frequencies, they just need time to adjust everything properly.
Example, HD 4890 didn't lower its memory clocks and they always run at 100%.

We've arrived at our conclusion regardless. The idle consumption of a similar Zen system is higher. It includes the CPU, now, if all else is the same... hmmmmm. I can imagine for Intel the way to gain more profit there is to completely disable a cpu. An idle voltage is still a voltage.

 

[ARF]

We've arrived at our conclusion regardless. The idle consumption of a similar Zen system is higher. It includes the CPU, now, if all else is the same... hmmmmm. I can imagine for Intel the way to gain more profit there is to completely disable a cpu.

Nope, chipset X570 is 12 or 14nm and probably it causes problems.

 

[Vayra86]

Nope, chipset X570 is 12 or 14nm and probably it causes problems.

If that is what you want to believe, who am I to stop you.

Some sources would be good though, instead of just hip shots.

 

[ShurikN]

Don't really see the point of a big.little uArch on desktop. Mobile/laptop sure, all the way, but desktop...

 

[ARF]

If that is what you want to believe, who am I to stop you.

Some sources would be good though, instead of just hip shots.

You can see that the X570 power consumption starts from a much higher base, idling at 7.35W with no NVMe drive attached. The yellow highlighted bars show max power usage der8auer observed with various combinations of NVMe Gen 3 and SATA drives, and one included a PCI graphics card running the FurMark benchmark too. Finally the bottom two results, in red, show power consumption when there is a Corsair NVMe gen 4 SSD attached, and in/active. Der8auer is surprised by how little difference there is between NVMe Gen 3 and 4 under load in terms of power consumption "because everybody kept telling us (at Computex) that the chipset has much higher power consumption because of PCI Express Gen 4." In summary the OC expert couldn't pin down why the chipset requires so much extra power in actuality. Hopefully things will become clearer as boards are tested by more tech review sites like ourselves, it is still early days.

der8auer examines AMD X570 chipset power consumption

Asserts it doesn't need a fan, and consumption isn't high due to PCIe Gen 4 device utilisation.

hexus.net

 

[Vayra86]

der8auer examines AMD X570 chipset power consumption

Asserts it doesn't need a fan, and consumption isn't high due to PCIe Gen 4 device utilisation.

hexus.net

If you look at B350 vs X570, the difference is 4W in idle on a stock CPU. Still only accounts for half the gap, stock vs stock. OC'd, the AMD board will usually run more efficiently in idle - both X570 and B350.

Looks like its a bit of both, at the very least. Regardless, because we've drifted off topic a little... there is STILL a gain here because being able to shut the CPU off entirely is of course profit anyway, over leaving it at a low voltage. If we discard the board from the total system power equation, there is still a significant chunk of idle usage there from the CPU in both camps. I mean this is 50W idle we're talking about. The board takes 4-8W... on desktop.

Of course we also can't just directly translate these numbers to a laptop situation with ditto CPU, but if Zen is a single chiplet that cannot be shut off versus a BIG little setup where the biggest idle usage can be removed, it needs no explanation what will be preferable for battery life. No matter how low and well it can clock down. Most devices are in idle most of the time...

 

[londiste]

If we discard the board from the total system power equation, there is still a significant chunk of idle usage there from the CPU in both camps. I mean this is 50W idle we're talking about. The board takes 4-8W... on desktop.

I think you have it backwards. Idle CPU should take very little power. My R5-2400G consumes 4W or less at idle. Intel CPUs I have at hand are similarly in a few-watt range. Board, on the other hand, can consume more power with all the controllers and devices in addition to the chipset.

 

[Vayra86]

I think you have it backwards. Idle CPU should take very little power. My R5-2400G consumes 4W or less at idle. Intel CPUs I have at hand are similarly in a few-watt range. Board, on the other hand, can consume more power with all the controllers and devices in addition to the chipset.

So what then would be the point of a big little setup? I struggle to find one if its not reducing idle usage.

 

[londiste]

So what then would be the point of a big little setup? I struggle to find one if its not reducing idle usage.

Idle usage of an Atom core is definitely in sub-W area and lower. Couple of Atom cores can run at full blast - 2GHz-ish, probably - in 4W. This means idle-ish low performance situations that Atom core can handle will result in much lower power draw.

 

[Berfs1]

The impact SMT has is almost universally beneficial, it's so rare that the performance degrades it's not worth eliminating it. I mean that's the whole point, otherwise this feature would have been canned long ago.

The thing is, the 8 core processor with SMT will be less expensive to manufacturer and actually use less power than an 8+8 processor with no SMT. Big.Little makes no sense whatsoever on a desktop.

And if someone is so hung on not having SMT they can just disable it, no need for an entirely different processor.

Big.little is supposed to help efficiency at low loads and at idle, however having a 8c16t cpu will indeed take less power than a 16c16t processor. But yes, 8c16t is cheaper than 16c16t, however not only is 16c16t more secure, it also will have better single threaded performance (and actually will have slightly better multithreaded performance too). That's actually why the i7-9700K can beat the i9-9900K (stock configurations) in certain games, since they have similar clocks but the 9700K has HT disabled. (and yes, you can disable HT on the 9900K too)

So what then would be the point of a big little setup? I struggle to find one if its not reducing idle usage.

Perhaps the high performance cores will shut off when the system detects it is idling, so that alone will save power, and the low power cores can be active when the system is idling

 

[ratirt]

So it will be 8c16t + 8 small cores which performance ain't that great mainly to reduce power while not doing heavy tasks. I think that is the main idea of this. Why Intel shoves 8 small cores into a desktop processor is strange. The only thing that comes to my mind (reasonable explanation) is competing wit AMD with power efficiency? Why would you cripple desktop processor with this? Or maybe Intel can't make 16c processor with regular cores and this is the only way (because of yields? maybe?) Intel can make it if this is going to be a 10nm processor to compete somehow with AMD products.

 

[Octopuss]

What the hell is big core and small core?

 

[trparky]

Big.little is supposed to help efficiency at low loads and at idle, however having a 8c16t cpu will indeed take less power than a 16c16t processor. But yes, 8c16t is cheaper than 16c16t, however not only is 16c16t more secure, it also will have better single threaded performance (and actually will have slightly better multithreaded performance too). That's actually why the i7-9700K can beat the i9-9900K (stock configurations) in certain games, since they have similar clocks but the 9700K has HT disabled. (and yes, you can disable HT on the 9900K too)

But why would we care about this kind of efficiency in a desktop? Don't get me wrong, in a notebook/mobile setting? Yes, most definitely. But a desktop? Not a chance! Most desktop users expect full power performance from our desktops, it's not like it's limited in power usage or cooling capacity.

 

[Assimilator]

What the hell is big core and small core?

ARM big.LITTLE - Wikipedia

en.wikipedia.org

But a desktop? Not a chance! Most desktop users expect full power performance from our desktops, it's not like it's limited in power usage or cooling capacity.

By the same "argument", the gas-guzzling cars of the 1960s should never have been superseded by more efficient models. *facepalm*

 

[Octopuss]

Uh, so the CPU would have twice as many cores, but only half of them can be active at any given time, or?

 

[Berfs1]

But why would we care about this kind of efficiency in a desktop? Don't get me wrong, in a notebook/mobile setting? Yes, most definitely. But a desktop? Not a chance! Most desktop users expect full power performance from our desktops, it's not like it's limited in power usage or cooling capacity.

Because your electricity bill is going to deal with that? And you may not think it is a big deal, but it can also affect your house's power circuitry, if it can't handle multiple computers (which I know some people actually use multiple high performance computers), your whole house's circuit will fault and activate the breakers. That is why we don't want 300W CPUs. Because it is just too much for a mainstream CPU. Sure, for workstation CPU that is fine. But for a common household processor, that is too much. Sorry, but 300W is just too much from a mainstream processor running stock.

 

[ToxicTaZ]

Intel LGA 1200 socket PCIe 4.0 (DMI 4.0)
With Intel Rocket Lake CPU support

Intel LGA 1700 socket PCIe 5.0 (DMI 5.0) "DDR5 USB4 WiFi-6E
With Intel Meteor Lake CPU support

Meteor Lake is Intel 7nm