C32HG70 FreeSync range

Jon_Snow · 15 Sep 2017 at 13:21

Some reviews said this range is 80~120 or 48~144, not sure which is correct, can anyone help? thx.

aatu · 15 Sep 2017 at 18:11

I would wager that the 80-120 is the FreeSync range for HDMI, and 48-144Hz is for DisplayPort. I think mine has 40-70Hz and 48-144Hz.

Then again, my sources say that the FreeSync range is 80-120Hz, but the official refresh rate is 144Hz...? But it's apparently FreeSync 2, so it should have FRC by default (which means you don't have to worry that much about the minimum range).

AmateurExpert · 16 Sep 2017 at 15:32

aatu said:
But it's apparently FreeSync 2, so it should have FRC by default (which means you don't have to worry that much about the minimum range).

You meant LFC (low framerate compensation) rather than FRC (Frame Rate Control - a technique for increasing colour gamut by temporal dithering).

But on the Samsung CHG70 monitors, it's impossible to find a decent review (though this is a problem with monitor reviews in general) - closest is Lim's Cave, but even then his reviews lack key detail. We don't know which inputs he tested with, but at least he didn't just regurgitate the marketing info as Technopat did (they initially stated the Freesync range as 48-144, but later corrected themselves in the comments when challenged). Apparently they were going to follow up, but there has been no update.

aatu · 16 Sep 2017 at 16:14

AmateurExpert said:
You meant LFC (low framerate compensation) rather than FRC (Frame Rate Control - a technique for increasing colour gamut by temporal dithering).

Aah, yes. I mistakenly remembered it as FrameRate Compensation, so forgot the L.

BaroUK2 · 16 Sep 2017 at 16:29

For your information you can also use CRU to edit freesync ranges.
https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

AmateurExpert · 16 Sep 2017 at 20:33

BaroUK2 said:
For your information you can also use CRU to edit freesync ranges.
https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

Lim already tried this and was only able to extend the range from 80-120 to 80-140Hz.

AmateurExpert · 16 Sep 2017 at 20:38

aatu said:
Aah, yes. I mistakenly remembered it as FrameRate Compensation, so forgot the L.

Yeah the acronym soup around display technologies is particularly terrible, and it's even worse when advertised features (such as Freesync 2 and its implied inclusion of LFC, also HDR) don't match up to reality as apparently the case with these monitors.

Jon_Snow · 17 Sep 2017 at 07:13

If the FreeSync range is 80~120, I will not buy this monitor...
I want to buy a monitor with HDR, 1440P, 144hz, IPS (FreeSync or G-Sync)

I have consider this two choice but seems their is not a monitor satisfy my criteria whether FreeSync or G-Sync.
Maybe I should postpone my purchase plan

.

1. RX Vega 56 + FreeSync Monitor (First choice, My GPU is R9 Fury now)
2. GTX 1080Ti + G-Sync Monitor (Second choice)

aatu · 17 Sep 2017 at 08:27

Regarding the "unacceptable" FreeSync range, are you worried about the upper or lower limit? Usually the lower limit SHOULDN'T be an issue because of the LFC. Because if the game is operating at 30fps, it can multiple the framerate to reach 90Hz, which falls under the range.

But I also noticed a small discrepancy in the range setup, which I am actually slightly worried about: the 60-80fps range would apparently fall outside FreeSync operation, as it isn't directly inside the FS range, and can't be multiplied to it, either. I just find it hard to believe that the R&D personnel would have let something as simple as this pass through the design phase... Before purchasing a monitor with such a range, you should probably consult the manufacturer, first.

Actually, I thought LFC required the range maximum to be at least 2.5x the range minimum. And 2.5 x 80 would be 200Hz, so something doesn't add up. Well, technically 2x is the bare minimum, and 0.5x is just a buffer. But 2x 80 would still be 160Hz, so even that is not enough. Anyway, searched around, and found this discussion thread, if anyone is interested:
https://www.reddit.com/r/Amd/comments/5cv2kj/does_lfc_freesync_support_still_require_that_the/

But it doesn't seem like they've found any explanation to this.

AmateurExpert · 17 Sep 2017 at 12:09

Jon_Snow said:
If the FreeSync range is 80~120, I will not buy this monitor...
I want to buy a monitor with HDR, 1440P, 144hz, IPS (FreeSync or G-Sync)

You're not alone. You can join the rest of us in this thread to bemoan the lack of monitors that we actually want to buy. Closest out there is the Acer XF270HUAbmiidprzx, but this doesn't have HDR and some reviews have highlighted quality problems - though this is all too common with many monitors these days.

AmateurExpert · 17 Sep 2017 at 12:30

aatu said:
... the 60-80fps range would apparently fall outside FreeSync operation, as it isn't directly inside the FS range, and can't be multiplied to it, either.

Bingo.

aatu said:
Before purchasing a monitor with such a range, you should probably consult the manufacturer, first.

I wouldn't expect most potential purchasers to have enough technical knowledge to check with the manufacturer on features claimed in marketing material that are technically suspect.

aatu said:
But 2x 80 would still be 160Hz, so even that is not enough.

Indeed - Lim's Cave has a video showing that LFC is definitely not kicking in when dropping below 80Hz due to the CHG70's limited refresh rate range.