Although the review sample was provided by Cooler Master, the review itself is 100% unbiased. All opinions are my own.
Review: Cooler Master MasterMouse S (newly updated cable)
If you have any questions, suggestions or corrections to make please don't hesistate to comment below. Furthermore, if you want me to do any comparison pics just let me know. Since this is my first attempt at doing a proper review I'm thankful for any criticism.
The MasterMouse S comes with the Pixart PWM3330 sensor which is the budget version of the PWM3360. Aside from the lower CPI range (up to 7200 CPI) and the lower PCS (perfect control speed) it is identical to the 3360 in terms of features. Further down below I’ll be doing some testing to see whether the 3330 behaves similarly to the 3360 in terms of sensor smoothing as well. The switches for the main buttons are Omrons that are rated for 20 million clicks. The cable has a length of approximately 1.8m. The mouse has one button for switching CPI steps and two side buttons on the left side despite having an ambidextrous shape. All the buttons can be fully remapped in the software (details see below). Lastly, the MasterMouse S features RGB lighting with 16.7 million colours.
The packaging includes the mouse and a short manual. As can be seen in the pictures, the cable is unfortunately not wrapped around the casing but folded somewhat tightly. There are no additional mouse feet in the box, so if you choose to open the mouse in order to get rid of the internal weight you either need to be careful when removing the feet in order to be able to re-apply them safely afterwards or get some generic aftermarket feet (such as the IME 3.0 ones from Hyperglide) as there are no specific feet available for the MasterMouse S. However, I’ve been informed by Cooler Master that they are currently considering providing spare feet on request, similarly to how it’s currently possible for the MM530 and MM520. As a side note, the packaging of the ‘new’ MasterMouse S is virtually indiscernible from the old one. Since the ones with the old cable should be out of stock by now getting one with the new cable should be almost guaranteed.
One of the biggest complaints about the MasterMouse S back at release was the printer class cable. Albeit not braided its stiffness was second only to the worst offenders from Logitech or Dream Machine in that regard. It was somewhat usable with a bungee (see the picture) but still far from ideal. Thankfully the new rubber cable is much better and almost on par with Zowie rubber cables. It’s still not as flexible as it should be, but it didn’t bother me during use both with and without a bungee. However, if you really want to get as much as possible out of this mouse installing a paracord is recommended (and can be conveniently done during the process of removing the internal weight).
Shape and weight
Pictures of how I hold the mouse can be found in the picture album below (please ignore the scratch marks, my cat mistook my hand for a mouse). For reference, my hand measurements are 19x10 cm.
Similarly to the Logitech G Pro shell the MasterMouse S only has side buttons on the left side despite being an ambi shell, hence making it most suitable for right-handed users. As can be seen in the pictures the MasterMouse S is a small to medium sized mouse. The overall shape is among the best I’ve tried in my mousing life. In fact, the feel in hand is somewhat comparable to a shorter yet taller WMO. It’s slightly shorter than most other mice in that size category which allows me to extend my fingers almost to the upper edge of M1 and M2; at the same time the greater than average width enables me to grip it tightly without having to apply a ‘death grip’. The hump is more towards the back and provides ample palm support. The sides are fairly straight with a subtle curve that makes it easier to pick the mouse up. I’d say this shape is most suited for claw gripping (I’m a claw gripper myself), but I could see it being usable with fingertip grip as well. The main buttons are not separated from the shell.
A note on the sensor position: As can be told from the pictures the sensor placement is below the centre. Personally, I don’t have much of a problem with that, but there are people who prefer the sensor centered or even higher positioned. In my case you can see that the sensor is roughly at the same height as my thumb which is usually a good indication that mouse control will feel natural.
Moving on to the weight, my scale shows ~93g with a bit of cable, so the actual weight is supposedly in the 90g range. As most people most likely already know by now, there is a weight inside the mouse which is merely screwed to the top of the shell and thus can be easily taken out. The weight and the screw weigh approximately 13g, removing them therefore lowers the weight to about 77g which indeed makes a big difference. Weight balance is improved as well since the MasterMouse S is a bit back heavy with the weight installed. In conclusion, removing the weight is heavily recommended.
Another common complaint about the originally released MasterMouse S was the build quality. I’ve got two copies of the ‘old’ MasterMouse S. The first one suffered from main buttons that overlapped/grinded against each other and from either the bottom of the shell or the feet scraping on the mouse pad. The second one had no issues with scraping but an ultra-mushy left click. Thankfully the ‘new’ Mastermouse S I’ve tested has no issues with overlapping main buttons. However, there still is some scraping present on my unit, albeit not as pronounced as on the first one.
Compared to the ‘old’ Mastermouse S the buttons are pretty much unchanged. The main buttons require little force to actuate but more than the buttons of current Logitech mice. The clicks are fairly tactile with little to no post- or pre-travel and therefore easy to spam. They’re also quite uniform on my unit. Side buttons have a moderate amount of post- and pre-travel and a somewhat flimsy feel, overall they’re decent enough though. The scroll wheel doesn’t rattle or make too much other noises; the steps are weakly defined. The button press itself is fairly heavy. The CPI switch button is standard.
The coating is among the better ones I’ve seen. It’s nowhere near as slippery as the coating of current Zowie mice and it also doesn’t attract dirt/finger marks too much. The mouse feet (see pictures) glide well enough, but they certainly could be improved. I’d recommend changing them to aftermarket feet after opening the mouse up for removing the internal weight. It is also worth noting that they’re already a bit scratchy right out of the box.
Neither the ‘new’ MasterMouse S nor my older ones have any rattle.
The default steps OOTB are: 400-1200-4000-7200. The measured (rounded) CPI, however, is consistently higher than the nominal CPI and differs quite a bit from the latter: 430-1280-4270-7700. (Note: Although my testing isn’t perfectly accurate it is accurate enough to determine that the actual CPI is consistently higher than the nominal one. The margin of error increases with CPI.) The lighting isn’t active OOTB, making it impossible to tell the steps apart aside from on-screen cursor speed.
Let’s talk methodology first. Given that the difference in movement delay that I’m trying to determine here is in the range of 1-6 ms the testing method needs to be very exact. To this end I’m using the program MouseComparator. The procedure is as follows: First, you need to find a mouse that functions as a baseline. In this case I’ve chosen the G403 since the 3366 used in it is known to have no visible smoothing (2 frames which equals 0.4 ms) at all CPI steps along with little to no CPI deviation. I plug both mice into adjacent USB ports and set them to similar CPI steps and the same polling rate. Any CPI deviation can be normalised in MouseComparator which makes the results as consistent as possible. The normalisation can be considered correct if the two curves closely mirror each other. I also make sure that each mouse has been moved before starting to test to ensure that the sensor hasn’t entered rest mode. I then put the two mice next to each other so that they have contact and gently push one of them in the direction of the other. Obviously, the mouse being pushed first may have an advantage of 1-4 ms over the other which has to be accounted for in the overall latency calculation. However, note that in every test the G403 was the mouse being pushed second. The mouse movement is collected and plotted. The plots are zoomed in to show the difference in ms. The curve on the left denotes the mouse that has less motion latency. It’s also worth noting that theoretically a frame averaging as part of sensor smoothing of x ms should show up as x/2 ms in the plot (source
In order to show that my testing isn’t flawed I’ll provide two baseline tests. First there’s the Thermaltake Ventus X RGB against the G403. The Ventus X has a standard 3360 which is known to have the same amount of smoothing as the 3366 below 2000 CPI and 32 frames of smoothing (~6.4 ms) above 2000 CPI.
As you can clearly tell from these plots the cursor path is virtually identical at 1600 CPI but a bit different at 3200 CPI, confirming the reliability of the testing.
Here’s the same arrangement with a Roccat Kone Pure Owl-Eye. In this case it’s even more obvious:
Let’s see how the MasterMouse S fares at 400 CPI on stock firmware.
My testing suggests that there is a slight delay of up to 1ms between the MasterMouse S and the 3366 at 400 CPI on stock firmware. However, getting sensible results was quite difficult in this case, so take this plot with a grain of salt. See this plot showing miniscule differences as well for comparison:
Testing with the most recent firmware
For this test I’ve updated the MasterMouse S to the most recent firmware and set the nominal CPI steps to the standard values of 400-800-1600-3200. Unfortunately, the CPI deviation is seemingly the same as on stock firmware with the measured CPI steps being 435-870-1730-3450. If you’d want your actual CPI to match the one you’ve set you’d have to choose a much lower value to get the CPI value you actually intend to get. Hopefully Cooler Master addresses this in a future firmware update.
No surprises here. This plot closely resembles the one that was done on stock firmware.
Still no visible sensor smoothing.
Still no visible sensor smoothing.
Now things are getting interesting. I’ve repeated this test many times to ensure that I don’t fall victim to cherry-picking any results. From the plots it is quite clear that the 3330 in the MasterMouse S has no visible sensor smoothing at the 3200 CPI (actually 3450) step. Therefore it is safe to say that the 3330 behaves differently from the 3360 in regard to sensor smoothing as the smoothing is increased to 32 frames (6.4 ms) above 2000 CPI on the 3360. A short Paint test also indicated increased jitter at the 7200 CPI step which suggests that there is no additional sensor smoothing across the whole CPI range. I did not test this specifically though since the margin of error is too great at such high CPI.
The obligatory Paint test doesn’t show anything unusual. There is no angle snapping at any of the tested CPI steps and some minor jitter that increases with CPI. This result matches the testing done above.
For whatever reason, my attempts to provide a good looking plot of a 4+ m/s swipe at higher CPI were unsuccessful. However, most users should be content with knowing that the 3330 in the MasterMouse S can track up to 4 m/s without issue. I also tried to make the MasterMouse S spin out during gameplay and simply couldn’t do it. So although it is reasonable to assume that the PCS is lower compared to the 3360, the 3330 still has a PCS that should be high enough for the vast majority of users.
The software is rather interesting. First you need to install a hub software called Cooler Master Portal which allows you to manage several Cooler Master peripherals at once (in case you happen to own more than one). Then you need to specifically install a driver module for the MasterMouse S that is accessible separately. The software itself is among the better ones I’ve seen. It’s fairly lightweight both in terms of disk space and memory usage and offers a decent range of options. There is not only the option to remap every button but also a functional equivalent to Logitech’s G-shift function which allows you to assign every button with a secondary function upon pressing a specified shift button.
The lighting includes two zones (scroll wheel and the underside of the mouse) that can be operated separately. There are several lighting modes such as breathe, static or CPI switch; the colour accuracy is decent throughout. It’s also noticeable that you can get it to display a rather dim white which isn’t possible on every mouse.
The internal memory of the MasterMouse S is capable of storing up to four CPI steps. Unfortunately there is no way of deactivating one or several of them in case you only want to use a specific one. CPI can be adjusted in increments of 100. The USB polling rate can be adjusted to 125Hz, 250Hz, 500Hz and 1000Hz. Being able to set a 125Hz polling rate can be useful for some older games so having that option is certainly a plus. All polling rates were stable on my system. An on/off toggle for angle snapping is available as well, the effect is rather tame though. Lift-off distance can be set to either low or high with ‘low’ being below 1 DVD and ‘high’ being between 1 and 2 DVDs on a cloth pad. There’s also the option to do a surface calibration for lowering LOD even further, but since it’s already low enough most people probably won’t need it.
There’s also an option that deserves some special praise. The debounce time (click delay) for the main buttons (M1/M2) can be adjusted in steps of 4ms from 4ms to 32ms, which enables one to either get a click latency almost on par with Logitech’s mice or a higher debounce in case you’re experiencing double clicking. I wish more companies would include this incredibly useful option in their software.
Finally, the software also offers macro functionality (which I didn’t test since I don’t use macros) and up to five profiles that allow you to quickly switch between entirely different setups.
I did notice a small bug: After uninstalling the software and restarting the PC for the first time, the OS cursor speed is set to maximum. On subsequent starts the slider stays at the set value.
When I got myself the MasterMouse S with the original cable I was quite delighted with it since I could perform incredibly well with it in games. However, the cable and overall quality left much to be desired, although some issues went away over time. The ‘new’ MasterMouse S has successfully improved on these concerns. The cable is much better and the overall quality more solid. It’s also worth mentioning that the 3330 featured in the MasterMouse S not only performs similarly to a 3360 but actually has a particular advantage over it (no sensor smoothing that’d kick in above 2000 CPI). The only complaints left are the internal weight that is still present and the rather large CPI divergence which will hopefully be addressed in a future firmware update.
Click here for the picture album