Is this the Ultimate Monitor? Acer CG437K S 43” 4K 144Hz Review

This behemoth is Acer’s 43” CG437K S, a newer version of their existing K P model. Both of which sport a 43” 3840×2160 144Hz VA panel, HDR1000 certification, a supposed 1ms ‘VRB Response Time’, 90% coverage of the DCI-P3 spectrum and is even fully G-Sync Compatible. For those kinds of specs, you’d expect this to require a second mortgage (or for anyone under 40, their first), and yeah you’d be right. Acer lists this at $1,599 on their US site, so it’s safe to say this is a halo tier product.

Let’s start with the main attraction, the panel. You get 43 inches of 4K 144Hz magic beamed into your eyes with a max of 1000 nits of peak brightness in HDR, or around 750 nits in SDR as my SpyderX reported. To say this is bright enough for any non-HDR situation is possibly an understatement. You also get 93% coverage of the DCI-P3 spectrum in my testing, and a calibration report in the box quoting an average DeltaE of less than 2, meaning if you want to both work and play on this you should have a rather good time. The static contrast ratio is quoted as 4000:1, personally I measured more like 3500:1 with the SpyderX although I’m inclined to give the panel the benefit of the doubt here as the SpyderX is likely to be a touch inaccurate at those sorts of high brightness levels – plus you can enable the “ACM” or “Active Contrast Management” feature with supposedly offers 100,000,000:1 instead.

To the eye, the content looks pretty stunning, with rich, vibrant colours jumping out at you from the moment you sit down in front of it. Considering this is the size of a TV, it wouldn’t be out of place to use it as one. The biggest drawback here is that thanks to the use of an edge-lit backlight, while this does supposedly support local dimming, it doesn’t support full-array local dimming meaning the HDR experience is fairly lacklustre. There’s no MiniLED backlight, and it’s no OLED, although personally I wouldn’t be too upset about that as the SDR experience is already pretty fantastic.

Equally strangely, unlike the Philips Momentum 55 with its included Bowers & Wilkins soundbar, the CG437K only includes two rather compressed and tinny 10W speakers, and only a 3.5mm headphone jack for audio out meaning you’ll likely want to run your own sound system from your PC – unless of course you want to use this with a console, in which case you’ll either have to live with the built in speakers or use that headphone jack for a set of 2.1 speakers instead.

To top off the unusual I/O decisions, you only get 2 HDMI ports (albeit HDMI 2.1 ports) and one DisplayPort 1.4 port, as well as a USB C port that does appear to support DP ALT mode, but on the laptop I tested it with I could only get it to run at 1440p60, not even 4K60, although im not sure if that’s just this laptop or not.

While that is plenty for a couple consoles and a PC, other options like the Momentum feature 3 HDMI ports alongside DisplayPort and USB C for a touch extra flexibility. Happily though, thanks to the use of HDMI 2.1 both the PS5 and Xbox Series X can run at up to 4K 120Hz, and a PC can use either HDMI or DisplayPort to hit the full 4K 144Hz, even with 10 bit colour!

Since I mentioned the consoles and gaming, it’s worth taking a second to talk about its response times. Being a VA panel, this was never going to set any records, even if Acer are hell-bent on insisting it will with their purposefully misleading “1ms VRB Response Time” figure plastered everywhere. “VRB” stands for “Visual Response Boost”, which is Acer’s name for backlight strobing, AKA ULMB. The figure they are quoting is what most quote as the “MPRT Response Time”, and is not a measure of the panel’s performance in any way. What it means is with the “VRB” setting on “Extreme”, the monitor turns the backlight off for all but 1 ms per frame, leaving you with a red glow fading to black in between. Personally, these modes give me almost instant headaches, so are unusable, and even if you don’t get that you are likely to experience a considerable amount of eye strain thanks to the flickering.

I suspect the reason Acer is so happy to quote the ‘how-long-we-turn-the-screen-on-for’ time is the actual grey to grey response times are just… dreadful. On the default “Normal” overdrive mode, you can expect response times as bad as 42 ms on the darker transitions, or an average of nearly 18 ms. If you manage to have it allow you to change the overdrive settings with adaptive sync enabled (something I had inconsistent trouble doing) and set it to “Extreme”, you do get a slight reduction down to more like 13 ms average, although still with some pretty terrible results especially at lower brightness levels.

That translates into pretty poor motion performance, as in the UFO test you can see just how many copies are present on screen at once especially in the darker areas and just how clear they still are. I count 5 of 6 copies, with the most recent frames still being bright enough to be able to trick me into thinking they could be the most recent ones. Setting the UFOs to a faster speed shows just how big a problem that can be – the entire screen is full of still visible frames!

Actually gaming on it doesn’t feel quite as bad, although for fast paced games where accuracy and reaction times are important, this likely isn’t for you. I found it hard to hit shots, or even feel confident that when I pressed left click my cursor was actually aiming at an enemy. For something like a racing game I wasn’t quite as bothered, although with just how slow the panel can be it did remove a lot of the sharpness that comes from this being a 4K panel, making the game feel sluggish and a little blurry or smeared. For more story based, slow paced games I think this would be fine, but as your next pro esports display? Probably not.

I am happy to report though that the input lag over HDMI using my Time Sleuth was around 3.6 ms, which while not as impressive as a number of the 1 ms or lower displays I’ve tested previously, is still fairly reasonable and perfectly adequate for this type of display.

What I don’t think is all that reasonable is the stand – specifically its complete lack of adjustability. You can’t even tilt this slightly, which would have been a welcome adjustment for me personally. While this seems to be a common trend with this style of display, Philips managed to allow their 55” soundbar equipped Momentum 55 to tilt (for considerably less money I might add), so come on Acer. At least you can use the VESA 200×100 mount if you want to wall mount it. Interestingly the stand’s large singular foot has some slight mouldings to allow controllers to somewhat rest on top. It’s not a full pad, the controller still rests on the desk, but I guess it’s a nice touch for the console gaming market.

Another honestly baffling decision is the inclusion of these ARGB strips. These strips, sized relatively well to mount on each side of the rear of the display, include magnets to stick them to… Nothing. Instead you’ll have to use the included sticky tape to stick these to the display… wherever you see fit. Acer could have built these in, or at least put indents in the rear panel where they are meant to sit and left connectors in place so you can hook them up easily, instead of giving you these four massive, ferrite cored wires and individual connectors on the I/O rather than being able to daisy-chain them together (since they are addressable LEDs too). Oh and to top it all off, these don’t even do what Philip’s Ambiglow can do by analysing what is on the screen and projecting the average colours out to help ‘extend the display’ and increase immersion, no these are the usual rainbow pattern, or for use with the only game listed as supported, League of Legends, to “respond to your actions in-game!”… Again, come on Acer.

I think the final nail in the coffin for the CG437K S is actually the competition. I’ve mentioned the Philips Momentum 55 which is a pretty equal (if a touch larger) panel, but with the benefits of being a better all-rounder TV replacement style display all for £900 right now – but the real competition I’d say comes from OLEDs. Philips sells a 55” 120Hz OLED for just under £1000, and LG just launched their 43” C2 OLED which also supports 120Hz and quotes low input lag as one of its key features. That is a touch pricey at £1400 right now, and apparently there is an issue where the first batch are using LG’s older panel tech so you’ll be better waiting a touch longer for the newer panel to be included, but you get instant response times, an infinite contrast ratio and a much better HDR experience, likely better speakers too and all for fairly similar money.

All in all the CG437K S definitely has its strengths, but it has a fair few weak spots that make it hard for me to overly recommend, especially with its eye-watering price tag. I certainly wouldn’t call it bad by any means, it’s still a pretty great experience to use, but if you are playing with this kind of money I’m not sure this would be the best option for that cash. Maybe at a lower price tag, sub £1,000 for sure, it might start to make sense, but considering the older K P model is still listed for £1,100 on Amazon right now I somewhat doubt that.