News AMD Hybrid CPUs: No Point in Big.Little for PCs Unless OS Can Use It

[jasonf2]

If you look at the 5950 and 5900, when using all cores they only have 6-7 and 7-8W per core available,that IS a low power state and if you have a little core that can give you better performance at such low power it can be useful for desktops and especially for high core count.
Not much helpful for the normal user that doesn't even need that many cores but for special use cases it could possibly be helpful.
https://www.anandtech.com/show/1621...e-review-5950x-5900x-5800x-and-5700x-tested/8

The use case I am talking about is "always on" on battery powered devices, something that X86 has not faired well in. Most phones today do a very good job of sipping juice while the screen is off and still being awake and able to respond. Big.little lets those devices run low power state tasks without having to wake up the bigger cores giving significant screen off power advantages. This is also the reason though that the OS has to support it because without advanced scheduler support to take advantage of it, it is useless. No one is going to care about a few watts reduction on a desktop in low power mode. But on laptops the always on feature will become a standard play and those watts do matter when we are talking about the difference between a week long standby discharge and a day long one.

 

[TJ Hooker]

If you look at the 5950 and 5900, when using all cores they only have 6-7 and 7-8W per core available,that IS a low power state and if you have a little core that can give you better performance at such low power it can be useful for desktops and especially for high core count.
Not much helpful for the normal user that doesn't even need that many cores but for special use cases it could possibly be helpful.
https://www.anandtech.com/show/1621...e-review-5950x-5900x-5800x-and-5700x-tested/8

Drawing 6-8W for the core only (so not including uncore power draw) is still very different than mobile chips where the entire SoC draws less than that.

Edit: Oops, maybe you were just referring to the power draw relative to lightly threaded loads where one core can draw ~20W. That's an interesting point, maybe that ratio (~7 compared to ~20) is similar to the ratio between the power draw between little and big cores in mobile chips.