I see alot of speculation that the Helios is locked via BIOs but that' not the case.. the hardware for the monitor itself must support HDMI 2.0.
On my Facebook group (Helios 300) we've compiled a list and will update this one as new monitors emerge confirmed working.
Here is a list of external monitors that can reach above 60hz via HDMI (up to 240hz) which can be used by the Helios. Some of the monitors on this post are currently being used by owners of the Helios and confirmed working at their respective resolution.
If you find another monitor comment below and I'll add to the list.
(I require picture confirmation)
-------------------------------------------------------
ViewSonic XG2402
24.0" 1920 × 1080 TN monitor (FreeSync over DP and HDMI)
Maximum 144 Hz over HDMI
-------------------------------------------------------
AOC G2460PF
24.0" 1920 × 1080 TN monitor (FreeSync over DP only)
Maximum of 120 Hz over HDMI
Options beyond 60 Hz will not be available natively, the user must set custom resolutions.Note: Tom's Hardware review states that this monitor supports FreeSync over HDMI. This is incorrect.
-------------------------------------------------------
AOC AGON AG241QX
23.8" 2560 × 1440 TN monitor (FreeSync over DP only)
Maximum of 144 Hz over HDMI
-------------------------------------------------------
AOC AGON AG271QX
27.0" 2560 × 1440 TN monitor (FreeSync over DP only)
Maximum of 144 Hz over HDMI
-------------------------------------------------------
AOC AGON AG322FCX
31.5" 1920 × 1080 VA monitor (FreeSync over DP and HDMI)
Maximum of 144 Hz over HDMI
-------------------------------------------------------
Nixeus NX-VUE24A ( or B )
24.0" 1920 × 1080 TN monitor (FreeSync over DP only)
Maximum of 120 Hz over HDMI
Options beyond 60 Hz will not be available natively, the user must set custom resolutions."-B" variant is the same monitor with a different stand
-------------------------------------------------------
Samsung C24FG70
23.5" 1920 × 1080 VA monitor (FreeSync over DP and HDMI)
Maximum 120 Hz over HDMI
-------------------------------------------------------
Samsung C27FG70
27.0" 1920 × 1080 VA monitor (FreeSync over DP and HDMI)
Maximum 120 Hz over HDMI
-------------------------------------------------------
Samsung C24FG73 23.5"
1920 × 1080 VA monitor (FreeSync over DP and HDMI)
Maximum 120 Hz over HDMI
-------------------------------------------------------
Samsung C27FG73
27.0" 1920 × 1080 VA monitor (FreeSync over DP and HDMI)
Maximum 120 Hz over HDMI
-------------------------------------------------------
MSI G24C
23.6" 1920 × 1080 VA monitor (FreeSync over DP; unknown if supported on HDMI)
Maximum 120 Hz over HDMI
-------------------------------------------------------
MSI G27C2
27.0" 1920 × 1080 VA monitor (FreeSync over DP; unknown if supported on HDMI)
Maximum 120 Hz over HDMI
-------------------------------------------------------
MSI AG32C
31.5" 1920 × 1080 VA monitor (FreeSync over DP; unknown if supported on HDMI)
Maximum 120 Hz over HDMI
-------------------------------------------------------
MSI MAG24C
23.6" 1920 × 1080 VA monitor (FreeSync over DP; unknown if supported on HDMI)
Maximum 120 Hz over HDMI
-------------------------------------------------------
ASUS MG248QR
24.0" 1920 × 1080 TN monitor (FreeSync over DP only)
Maximum 120 Hz over HDMI
MG248Q non-R variant is limited to 60 Hz over HDMI
-------------------------------------------------------
ASUS XG27VQ
27.0" 1920 × 1080 VA monitor (FreeSync over DP and HDMI)
Maximum 144 Hz over HDMI
-------------------------------------------------------
ASUS XG258Q
24.5" 1920 × 1080 TN monitor (FreeSync over DP and HDMI)
Maximum 240 Hz over HDMI
-------------------------------------------------------
LG 27GK750F
27.0" 1920 × 1080 TN monitor (FreeSync over DP and HDMI)
Maximum 240 Hz over HDMI
-------------------------------------------------------
BenQ XL2540
1920 x 1080p
Maximum 240hz over HDMI
-------------------------------------------------------
AOC AG251FZ
24.5" 1920 x 1080p
Maximum 240hz over HDMI
Please hit like if this helped you. 👍