Monday, September 17th 2018
AMD Ryzen 2000H Series APUs for Mainstream Notebooks Spark TDP Debate Again
AMD introduced the Ryzen 2000H series APUs for mainstream notebooks. These chips are physically identical to the Ryzen 2000U series designed for ultraportable notebooks and convertibles; but come with higher CPU and iGPU clock speeds, and hence a higher TDP. The lineup includes two models for now, the Ryzen 7 2800H, and the Ryzen 5 2600H, both of which are based on the same 14 nm "Raven Ridge" silicon as the Ryzen 2000U series.
The 2800H features a 4-core/8-thread "Zen" CPU, with 512 KB L2 cache per core, and 4 MB of shared L3 cache; with clock speeds of 3.30 GHz, with 3.80 GHz maximum boost. The iGPU is a Radeon Vega 11, with 704 stream processors, and engine clocks of up to 1.30 GHz. If you'll recall, the Ryzen 7 2700U has very similar specifications, but only differs with a lower CPU nominal clock speed of 2.20 GHz (but same boost clocks), and one of the 11 Vega NGCUs being disabled. The difference in TDP between the two chips is enormous - 45W default TDP with configurable TDP as low as 35W for the 2800H; while the 2700U is just 15W default TDP, with configurable TDP as low as 12W.
The story repeats with the Ryzen 5 2600H. This chip has the same 4-core/8-thread CPU configuration as its Ryzen 7 counterpart, but with lower CPU clocks, and a slower iGPU that has just 8 NGCUs translating to 512 stream processors, clocked at 1.10 GHz engine clocks. The CPU ticks at 3.20 GHz nominal with 3.60 GHz maximum boost. The Ryzen 5 2500U, again, only has lower nominal clocks at 2.00 GHz, and even has the same iGPU core configuration; but the difference in rated TDP is huge: 45W vs. 15W.
So just how is it that the enabling of a tiny few components or increasing nominal clock speeds have such a tremendous impact on TDP? Perhaps there are other under-the-hood settings these chips have that make them more eager than their U-series siblings. Also, nominal clocks are clock speeds that each of the four CPU cores on the chip are guaranteed to run at, beyond which, depending on a number of factors, the PrecisionBoost algorithm awards higher clocks. On the U-series chips, PrecisionBoost is extremely conservative with boost clocks. Even so, could clock speeds really have such a profound impact on TDP? Join the debate in the comments below.
The 2800H features a 4-core/8-thread "Zen" CPU, with 512 KB L2 cache per core, and 4 MB of shared L3 cache; with clock speeds of 3.30 GHz, with 3.80 GHz maximum boost. The iGPU is a Radeon Vega 11, with 704 stream processors, and engine clocks of up to 1.30 GHz. If you'll recall, the Ryzen 7 2700U has very similar specifications, but only differs with a lower CPU nominal clock speed of 2.20 GHz (but same boost clocks), and one of the 11 Vega NGCUs being disabled. The difference in TDP between the two chips is enormous - 45W default TDP with configurable TDP as low as 35W for the 2800H; while the 2700U is just 15W default TDP, with configurable TDP as low as 12W.
So just how is it that the enabling of a tiny few components or increasing nominal clock speeds have such a tremendous impact on TDP? Perhaps there are other under-the-hood settings these chips have that make them more eager than their U-series siblings. Also, nominal clocks are clock speeds that each of the four CPU cores on the chip are guaranteed to run at, beyond which, depending on a number of factors, the PrecisionBoost algorithm awards higher clocks. On the U-series chips, PrecisionBoost is extremely conservative with boost clocks. Even so, could clock speeds really have such a profound impact on TDP? Join the debate in the comments below.
12 Comments on AMD Ryzen 2000H Series APUs for Mainstream Notebooks Spark TDP Debate Again
so, where's Ryzen 7 2800X hiding at? :kookoo:
UNLEASH THE RAVEN
As you say more turbo , and everyone loves more.
They're are also power save modes via Os that could help with efficiency so all good , no secret sauce here just binning for teired products.
Not all laptops are equal as my merrydale tablet (win10)thing would adequately demonstrate.
I do like how they breakdown the TDP. If the HSF isn't designed to handle 54w all of the time, the CPU may be expected to thermal throttle.
15W chips have to balance their tiny power limit between the CPU and iGPU. Under gaming, that means throttling both of them. I've seen 15W thin-and-light Raven Ridge laptops reported to run the GPU between 350-500MHz while gaming. Increasing the TDP to 25W on the same chip absolutely helps, but still puts a hard limit on performance.
The TDP of these parts should thus allow both the CPU and iGPU to run at or above their rated speeds without issue. For the iGPU, that means no throttling, while for the CPU, it might mean boosting above base clock even while the GPU is under load. Neither of these are even remotely possible for mixed workloads like gaming in the 15-25W space. And you know what? That's fine. It's not a problem, as we're still getting the best performance possible in that thermal/power envelope at this time. Releasing binned-for-clocks-and-power (not just low power like the U-series, or clocks regardless of power like the G-series) SKUs like this to allow the silicon to stretch its legs in a mobile form factor is a very good move. No different than Intel's 28+W Iris SKUs in previous generations, really. Well, except for those still having weaksauce GPUs, of course.