10-05-2018 08:48 AM - edited 10-05-2018 04:55 PM
It seems that this latest BIOS version (1.02) is causing a few different performance issues for the ThinkPad A485. Once obtaining my A485 I ran some synthetic benchmarks to judge CPU performance. After updating to the latest BIOS, I have noticed a decrease in performance on the order of about 10%. It seems that this BIOS update has allowed the CPU to exhibit more stable performance and CPU throttling behavior under constant load, e.g. as seen in the updates to this article:
but at the cost of some overall performance.
Adding to this, after having owned a ThinkPad A485 with a Ryzen 5 2500u and one with a Ryzen 7 2700u, it seems as though Lenovo's power management is aggressively holding back the Vega 10 GPU in the Ryzen 7 2700u, as opposed to the Vega 8 GPU in the Ryzen 5 2500u. Previously, in CineBench R15 (https://www.maxon.net/en/products/cinebench/) benchmarks, my A485 with the 2500u would achieve ~37fps during testing, while hardware monitoring software would show that the GPU was achieving a clock speed of about 800mhz. With my new A485 that has the Vega 10 GPU, it is impossible to achieve more than ~25fps under the same test and testing conditions and the hardware monitoring software shows that the GPU can not reach a clock speed higher than what I believe to be the near-base clock of 400mhz. With both laptops, this testing was performed with the Windows power setting being set to maximum performance, with the laptop plugged in and with "High Performance Mode" set within Lenovo's power management software. It is important to note that the laptop fan is barely audible during these tests, so it would seem that there should be more room for the GPU to increase in performance while still staying within a reasonable thermal envelope.
Further, testing with the 2500u CPU achieved the aforementioned ~37fps while providing very smooth frame rates while plugged in. With the 2700u CPU, the same test will show very noticeable lags when the laptop is plugged in, likely from the GPU clocking down for some reason. When the laptop is unplugged the frame rates are smooth, but the performance is still worse than the GPU from the 2500u CPU. What this suggests to me is that the laptop being unplugged is causing the CPU to clock down lower, allowing more power to go to the GPU and preventing it from clocking down, but I still believe that this is problematic. Here's a link to two videos exhibiting the problem:
I know that a BIOS update is planned for this laptop around mid-October, according to https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/ThinkPad-A485-Keyboard-Typing-Issue/m-p/..., however it seems that this update is currently only planned to address keyboard issues with the A485.
It would be great if Lenovo could provide some insight as to what is going on, since it seems that at this point the 2700u CPU is being held back greatly.
10-11-2018 07:52 AM
Lenovo, you need to fix your power management in this laptop. It seems you've fixed it for the E485, so why not here? It's obvious that this machine is capable of so much more yet you're absolutely destroying it's commercial viability via unreasonable thermal constraints and poor power management. Fix this, or lose many, many customers.
10-18-2018 08:25 AM
Same problem here. Please allow user to set reasonable TDP and T-Skin (STAPM) wattage in BIOS menu, this notebook is artificially limited by its questionable UEFI implementation.
11-30-2018 06:42 AM
Have you tried to load BIOS setup defaults after you've upgraded your BIOS ?
On the BIOS « Restart » tab (last one) , you have the « Load Setup Defaults » option, and then « Exit Saving Changes » or by pressing F9.
12-03-2018 01:12 AM
Engineering are looking into this, investigation is ongoing, but have also recommended the same as claurie suggested above; loading default settings in BIOS would appear to mitigate most performance degradation.
Please remember to make a note of any changes you may have made in BIOS before selecting default values, you will need to make thos changes again afterwards.
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