I would normally agree, however, the specs list the 4800U with a top turbo and all other specs (minus the one CU for graphics in the H) identical to the 4800H. That, and the in fact lower top speed of the GPU in H chips, leads me to believe that the H line APUs are actually lower-binned U chips. I hope AT or other channels can play with a 4800U and try pushing the thermal envelope; unfortunately, that'd void any warranty on the laptop.
They will definitely be lower binned chips - I'm not sure I was clear, so to reiterate, sometimes the "lower" bins tolerate voltage better than the "higher" ones, so even though they don't run as efficiently as the best bins they can run a little faster when given more juice.
This is just speculation, though - I don't know enough about the properties of the 7nm process :)
I'm a little confused why the 4700U isn't multi-threaded. It doesn't use much power does it? But it doubles multi-threaded performance. I understand if AMD wants to gimp the low end parts, but it seems strange to do on a Ryzen 7 chip.
I think you really are confused. Simultaneous multi-threading doesn't double the compute power.
The two threads sharing the same physical core can only run concurrently whenever they happen to require different parts of the core. Other times they end up waiting for each other. The total effect is that SMT will increase performance by around +25-30%.
8 cores with SMT will be equivalent to around 10 real cores.
This is also the reason why a 8c/8t (i7-9700K) is considered largely equivalent to a 6c/12t (~7.5 physical cores' worth of computational power), not accounting for differences in IPC, frequency or overclockability.
When you factor in that doing more work - you have double the number of threads and get +25% more work done - will consume more power. Running such a CPU at full tilt will require one or more of: - lower frequencies - lower voltages - better power delivery and cooling; or - better binned silicon (so you can run the same frequencies with lower voltage and get the required power usage).
I would postulate that 4800U is better binned, so can stay within the power and thermal envelope even with double the threads, without affecting frequencies too much.
Of course, it could also be that they're *not* binned any differently, or differently enough that it would make much of a difference; The worst quality APU silicon with all 8 CPU cores functional would probably be stockpiled for the future desktop products, or used now for the lower core count models (just with 2 - 4 cores fused off).
Surface Pro 8: 8C/16T APU, 15W, LPDDR4x, fanless, one can dream. I'm quietly excited about these new APUs but performance numbers take a back seat to energy efficiency for mobile parts. AMD will have trounced Intel if they can come up with a part for the Surface Pro tablet.
It is possible, and has been done, even at ultraportable- look at Acer Alpha and similar. 37Wh battery, runtime at full load is 112minutes= 20W power use- cooled fanless. And this is in a very limited 12" tablet formfactor. https://www.notebookcheck.net/Acer-Aspire-Switch-1...
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eastcoast_pete - Wednesday, January 8, 2020 - link
I would normally agree, however, the specs list the 4800U with a top turbo and all other specs (minus the one CU for graphics in the H) identical to the 4800H. That, and the in fact lower top speed of the GPU in H chips, leads me to believe that the H line APUs are actually lower-binned U chips. I hope AT or other channels can play with a 4800U and try pushing the thermal envelope; unfortunately, that'd void any warranty on the laptop.Spunjji - Thursday, January 9, 2020 - link
They will definitely be lower binned chips - I'm not sure I was clear, so to reiterate, sometimes the "lower" bins tolerate voltage better than the "higher" ones, so even though they don't run as efficiently as the best bins they can run a little faster when given more juice.This is just speculation, though - I don't know enough about the properties of the 7nm process :)
SolarBear28 - Tuesday, January 7, 2020 - link
I'm a little confused why the 4700U isn't multi-threaded. It doesn't use much power does it? But it doubles multi-threaded performance. I understand if AMD wants to gimp the low end parts, but it seems strange to do on a Ryzen 7 chip.Hul8 - Tuesday, January 7, 2020 - link
I think you really are confused. Simultaneous multi-threading doesn't double the compute power.The two threads sharing the same physical core can only run concurrently whenever they happen to require different parts of the core. Other times they end up waiting for each other. The total effect is that SMT will increase performance by around +25-30%.
8 cores with SMT will be equivalent to around 10 real cores.
This is also the reason why a 8c/8t (i7-9700K) is considered largely equivalent to a 6c/12t (~7.5 physical cores' worth of computational power), not accounting for differences in IPC, frequency or overclockability.
When you factor in that doing more work - you have double the number of threads and get +25% more work done - will consume more power. Running such a CPU at full tilt will require one or more of:
- lower frequencies
- lower voltages
- better power delivery and cooling; or
- better binned silicon (so you can run the same frequencies with lower voltage and get the required power usage).
I would postulate that 4800U is better binned, so can stay within the power and thermal envelope even with double the threads, without affecting frequencies too much.
SolarBear28 - Tuesday, January 7, 2020 - link
Interesting, so that is why the 4700U has a higher base frequency than the 4800U despite likely being a lower binned part.Hul8 - Wednesday, January 8, 2020 - link
Of course, it could also be that they're *not* binned any differently, or differently enough that it would make much of a difference; The worst quality APU silicon with all 8 CPU cores functional would probably be stockpiled for the future desktop products, or used now for the lower core count models (just with 2 - 4 cores fused off).serendip - Tuesday, January 7, 2020 - link
Surface Pro 8: 8C/16T APU, 15W, LPDDR4x, fanless, one can dream. I'm quietly excited about these new APUs but performance numbers take a back seat to energy efficiency for mobile parts. AMD will have trounced Intel if they can come up with a part for the Surface Pro tablet.wilsonkf - Wednesday, January 8, 2020 - link
It is absolutely not possible to cool 15W heat fanless in a labtop.neblogai - Thursday, January 9, 2020 - link
It is possible, and has been done, even at ultraportable- look at Acer Alpha and similar. 37Wh battery, runtime at full load is 112minutes= 20W power use- cooled fanless. And this is in a very limited 12" tablet formfactor.https://www.notebookcheck.net/Acer-Aspire-Switch-1...
mattkiss - Tuesday, January 7, 2020 - link
The article mentions support for LPDDR4X memory, but for the 4800H, I don't see it mentioned on AMD's site:https://www.amd.com/en/products/apu/amd-ryzen-7-48...
Perhaps Ian can clarify this.