At the time of writing, the HP Ultra-Fast Scroll 785M/780M suffers from severe lack of information. First let's address the naming: HP has made two versions of the same mouse, the 780M addresses the US market, while the 785M seems exclusive to the European area. My unit is the latter. To the best of my knowledge, there are no differences, although I would image the radio modules inside might differ in the channels/frequencies used depending on the locally enforced limitations. At the end of this review there is a section with information that HP could not address in a 30 minutes call with their business IT support that bumped me up to the alleged "engineering support".
The unboxing is rather Spartan. The HP Unifying dongle is hanging off the box, I would image to avoid people spending 15 minutes trying to find it in the bottom of the mouse. The mouse is safely stored inside a soft cotton bag that I would like to reuse during travels, but is lacking the usual compression laces to close it, so probably useless. There is a charging USB Type-C cable rated for 3A included, with no data pins as verified in the picture below: I think this should be inexcusable in 2025 given the very low prices for fully fledged Type-C Cables. It means from now on I'll a single cable in my drawer that can supply power but not data, generating hours of headaches when debugging electronics... Unless I bin it first.
The 785M has 6 clickable real buttons: Forward, Backward, left click, scroll wheel click, right click and finally the DPI button. I'm a bit disappointed by the lack of two side-wheel buttons, feature that is present in the Keychron M6. Each button is completely configurable through the HP Accessory Centre suite.
The scroll wheel used is the same kind of electromagnetic automated one you can find in the MX Master 3 and forward. It uses a set of electromagnet driven by the microcontroller on-board to alter the resistance when the user scrolls, and at the same time it records the speed of the wheel, making it possible to select multiple "sensitivities", aka when to switch between tactile and freespinning mode. It's a really cool feature, coming from 10 years of Logitech G502, and more recently of G502X, where the spinning mode can only be triggered mechanically. The scroll wheel switch is rather satisfying to press and is fully metallic as well.
The, also metallic, side scroll wheel is purely mechanical. It has a constant friction with the internal mechanism that makes it impossible to accidentally spin it. It has virtually no mechanical play, which is a very good sign. The ribbed helical pattern is incredibly grippy on the skin and rather cool to look at.
On the bottom of the unit we have the sensor, which is unfortunately unknown right now (I'll disassemble it once aftermarket replacement feets will be available), the power slide switch , a button and three LED indicators. The button is used to cycle the connection between your devices: you can connect up to three. I really like the attention to details: the slide switch has a very pragmatic colored indicator underneath. There are tens of certifications this mouse apparently has passed so I wouldn't worry about its RF emissions too much.
The vvery interesting quirky of this mouse is that it doesn't use a Lithium-Ion Battery, but instead HP opted for a Lithium-Ion Supercapacitor (LIC), which can be charged extremely quickly: HP claims 0 to 100% in 3 minutes over a 3A USB-C, which after some quick math gives around 200mAh, size perfectly in line with standard LICs.
Play the audio to listen to a sound comparison between the 502X and the HP 785M. We start with the clicky G502X, to then move onto the much more silent 785M. We test all buttons as well as the scroll wheel. Hear the "pop" when the free wheeling slows down and the HP automatically engages the tactile mode. Recording was done 15 cm away from the mices.
The lateral wheel is really a piece of beauty in this mouse. Moreover, each plastic mold seems designed to last rather than to cheap out. The hard plastic used on all buttons and teh front body is extremely grippy, I really appluade the choice of material and textures that HP went with.
The silicone material is excellent. It won't wear off like the MX Master 3, while retaining a very grippy feeling: I can move the mouse back and forth on the desk with only my palm, something I can't do on normal matte plastic like the G502's. Interesting decision to put the silicone seam dight next to the palm. I want to think it was done to increase the grip even further, but likely it was a mix of cost cutting and manufacturability trade-offs.
More on the lack of info over this mouse: yes! You can save the profiles directly on-board! Yes! You can download the manual here. I'm not sure why HP hasn't listed either of these things on their product page, neither in the American, nor British, nor Irish website. Once you download the HP Accessory Centre things will start to make sense.
The battery life is transmitted under a standard Bluetooth header, so your OS should be able to read it: so far I haven't seen it dropping below 100%. Notably, the Forward and Backward can be set so that a long press (1 second) activates the secondary function, which I personally mapped as "Copy" for the top button and "Paste" for the bottom one. All switches are very silent, perfect to use them in the office or while sneaking during a video call.
All sensitivities and DPIs can be set, but the DPI cycling button will only go through the predetermined setpoints that you can't change. Very inconvenient as my favourite one is none of theirs.
As soon as you press save, all the settings are stored internally to the mouse, and this is VERY important. Why? Because the HP Accessory Centre seems to have a major bug: it introduces random stutters displayed as your cursor teleporting from one side to the other of the screen. I've uploaded a video so you can understand better the issue. Effectively, it's almost impossible to use the mouse with this level of stuttering even in everyday tasks. It took me hours to understand what caused it: I tried my Logitech mouse, it was fine; I tried updating my PC drivers, nothing changed; I tried disabling the "Animation Effects" inside Windows's settings, no change. So I tried the mouse on my laptop: it was fine!! But can I trust my 60Hz laptop screen to be accurate? So as a last shot, I booted a live Fedora with KDE on my main PC... And the issue was magically gone! So that tells me it's something within my Windows install. I try a things for a few more minutes, until I realise that all this time I had the HP software running in the background and automatically launching at boot. Of course it was the HP software. I shut it down, and the mouse starts to work like an absolute wonder.
Under normal conditions, the HP 785m’s hardware looks like a direct competitor for the MX Master 4: it maintains roughly a 130 Hz polling rate, tops out at 9.30 clicks per second (CPS) when rapidly pressing the same button with two fingers, and the wheel in free spin mode can push a peak scroll speed of 44,496 pixels per second. As a comparison, the G502x with its 1000Hz polling rate can only reach a marginal upgrade to 11.5 CPS and 61776 pixel/s. This is despite the HP 785M never beeing designed for gaming in the first place.
However, the situation changes once we launched HP Accessory Center. Polling, which was effectively variance-free before, starts to fluctuate with an overall variance of 7.57 Hz with extremes going from 117.28 Hz up to 128.63 Hz, you can see this in the 2nd graph below. The added jitter translates directly into visible cursor stutter that makes the mouse effectively impossible to use for any task.
As I said before: luckily the Accessory Center is not required to run at all times, since the HP 785M can save the user bindings and preferences inside the on-board memory.
The manual is available here.
The software to set it up is HP Accessory Centre.
HP Accessory Centre is completely bugged and should be closed immediately after the mouse is setup.
The button bindings are saved internally.
The polling rate is 130Hz both via Unifying and Bluetooth
The mouse cannot be used via cable, only wirelessly.
The cable it comes with is charge only.
The website is currently broken and I can't register my device for warranty, since it won't recognise my Serial Number.
HP really needs to populate its own website with this information.
