Why is Parallels Desktop 16 dramatically worse than 15 in terms of game performance? For reference, my environment is listed below. MacBook Pro (15-inch, 2018) macOS 10.15.6 Processor :2.6 GHz 6core Intel Core i7 Memory: 16 GB 2400 MHz DDR4 GPU: Radeon RX 5700 XT 8 GB eGPU: Razer Core X Chroma Parallels Desktop 16 for Mac Home Edition Windows 10 Pro ver 2004 Build 19041.450 Upgrading the version to 16 makes the lag worse. If you downgrade to 15, there is some lag, but not as bad as with 16. If you check the Activity Monitor, the eGPU is working on both versions. Is this a lack of tuning for DX11 or Metal? If so, by what time will it be improved? Best regards.
Similar problem over here. I'm using a driving simulator software that only runs on Windows 10. Had absolutely no problems under PD15, the upgrade to PD16 makes the software unusable, there is less than 1 FPS remaining. MacBook Pro (13-inch, 2020) macOS 10.15.6 Processor: 2.3 GHz 4-core Intel i5 (10th) Memory: 32 GB 3733 MHz LPDDR4X eGPU: Razer Core X + AMD Radeon RX 5700 XT 8 GB Parallels Desktop 16 for Mac Pro Edition Version 16.0.1 (48919) Windows 10 Pro Education ver 1909 Build 18363.1082 In PD15 the software tells me it's using "Parallels using AMD Radeon RX 5700 XT OpenGL Engine", while in PD16 "Parallels using AMD Radeon RX 5700 XT OpenGL Engine (Compat)". The Activity Monitor tells me it's definitely using the eGPU in PD15 (up to 70% usage), however PD16 shows only about 2% usage for the eGPU and 0% usage for the built-in GPU. I have no idea on what exactly PD16 is trying to run my software. I had the option "Prefer external GPU" ticked both in PD15 and PD16. For now a downgrade to PD15 does the trick but god knows what will happen once Big Sur rocks around the corner...
UPDATE I contacted PD support and the second line was able to fix my problem! 1. Make sure that the virtual machine is shut down (Actions > Shut Down). If it is in a suspended state, please run it and then shut down (Actions > Shut Down). 2. Go to the virtual machine configuration (see: https://kb.parallels.com/117287 ) and click "Hardware > Boot Order > Advanced Settings > Boot flags". 3. Paste the following text in the "Boot flags" field: video.gl3=2 My software is now running smoothly in PD16 as it did in PD15. Unfortunately I wasn't told if they actually fixed something with that boot flag or just reversed something they upgraded before.
