Razer Lachesis review



I recently received this mouse as part of a christmas-gift from Razer, and I’ve decided to write a review about. In my opinion most hardware sites don’t have proper mouse-reviews. They either don’t know what they’re talking about, or are afraid they won’t receive any more review samples if they’re too critical. One notable exception is ESReality.

I think I do know what I’m talking about, and I don’t get review samples anyway 😉

You might have read my review of the Razer Barracuda headphone/soundcard combo, if you did, you’ll know I might be a fan of Razer, but not a fanboy.

Keeping with Razer tradition, the Lachesis is named after yet another venomous snake. I’ll start off with some specifications.

Specifications (and what they mean in plain English)

4000DPI 3G laser sensor

This means you can move 4000 pixels on screen with just 1 inch of mouse movement. Razer calls it a ‘3G’ laser sensor, which means you should be able to move this mouse at high speeds without the mousecursor skipping (like the Razer Copperhead 1G laser mouse)

On-board memory

Using the drivers you can save button bindings and macro’s to the memory inside the mouse. When you take the mouse to a PC that doesn’t have the Razer drivers, you can still use the settings in this memory. This way you can use advanced macro’s without the drivers. You’ll only need to drivers to save them to one of the 5 available memory-profiles.

Adjustable DPI

Using two buttons you can change the DPI in 125DPI intervals. This is again possible without drivers (as long as you keep two buttons bound to DPI changing of course).

1000Hz ultrapolling

By default, USB mice report 125 times per second (125Hz). The Lachesis can report 1000 times per second. This will cost you quite a few extra CPU cycles, but will make the mousecursor move smoother. I don’t use 1000Hz, but 500Hz, because I can’t feel the difference between 500 and 1000Hz ingame.

Shape and feel

lachesis-side.jpgBesides the specs there is the shape of the mouse. It’s an ambidextrous design, which means both lefties and righties can use it. Compared to the Razer Deathadder it’s a rather small mouse. A lot flatter and less ‘fat’. If you have big hands it might be a bit too small.

The Lachesis has a lot of buttons. 4 on top (5 if you count the scrollwheel), 2 on the left side and 2 on the right side. You can only use either the left-side buttons or the right-side buttons (depending on if you use your left or right hand). Compared to the oversized sidebuttons of the Deathadder the side-buttons on the Lachesis feel small.

The entire mouse is covered in a kind of rubber, the same used on the Deathadder. Like all Razer mice, the buttons are more sensitive comared than you’d expect from a normal mouse. This might take a while to get used to, but in my experience it makes your clicks register slightly quicker.

Scrolling feels exactly the same as on the Deathadder, almost silent and with very good feedback ‘clicks’.

The mousefeet are made of the Razer-standard teflon. Which ensures smooth movement across your mousing surface.


Driver panelThe drivers installed without problems. They look a lot like previous drivers and even have the same BSOD-inducing bug the Copperhead and Deathadder have.

If you use Windows XP and multiple users the following will happen: ( I know it will because I’ve tested three different mice on 2 different PC’s and 2 fresh XP installs)

1. You power on the machine and log in using USER1

2. You leave for work/school/cafe and keep the PC turned on

3. Your friend/girlfriend/brother/parents log in using USER2

4. When you get home you log out USER2 or use ‘fast user switching’ to switch without logging out.

5. Approximately 10-30 minutes later you’ll get a blue screen of death directly after pressing a mouse button.

Besides this annoying bug, the drivers worked perfectly.

Taking it out for a spin

lachesis3.JPGSure you can use this mouse on the desktop, but it’s meant to be a gaming mouse. So the natural thing to do was to start up Team Fortress 2 and start fragging!

Ingame I bumped the DPI to 4000 and lowered my game-sensitivity to compensate. This way I got the most precision while maintaining my normal mouse-movement-to-ingame-view-turn ratio. I normally use a Deathadder which is a right-handed mouse. The Lachesis being ambidextrous and smaller took a while to get used to. After an hour of fragging I mastered the Lachesis and played as well as with my Deathadder. The mouse is easy to hold, the buttons are easy to push and headshots are almost automatic. A very pleasant experience. However, I did start to experience some annoying quirks. While I was playing as a sniper, I had to lift the mouse off my mousepad (Razer Exactmat) to keep tracking an enemy. When the mouse left the mousepad, my sniper suddenly looked down. Simply every time I lifted the mouse, the view of my brave soldier would shift down a bit. Being a sniper is almost useless like this.

Another problem I found was ‘ghost movement’. Sometimes the mouse just shifts your view up/down/left/right. It only happened once very five minutes, but it also seemed to happen just when I was in combat.
Yet another problem is something I’ll call axis-lockup. This means that sometimes, for whatever reason, the mouse stops responding to all movement on a certain axis. You’ll either only look up/down or left/right. This ‘lockup’ only lasts a second, but is very annoying.

I tried switching mousing surface from my Razer Exactmat to my desk (white with some texture). Ironically this surface worked better than a Razer-brand mousepad. Still, the quirks remained. Today, Razer released a beta firmware aimed at fixing these problems, but unfortunaly it didn’t fix these problems for me.

These sensor problems should have been caught by Quality Control. I experienced these problems within the hour, there’s no way this could/should have slipped by QC.



+Good grip

+Ambidextrous design

+Great buttons

+High accuracy


-Lots of bugs in the current sensor firmware

-Only two of the four sidebuttons are usable


Obviously the Lachesis is a mouse with a lot of potential. Extremely high resolution, movement speed and a good design should make the perfect combination for a great gaming mouse. Unfortunately the bugs in the laser sensor make it impossible to recommend this mouse to anyone right now. Also it’s a rather expensive mouse when you compare it with the Deathadder and Diamondback 3G. Both of those don’t have the sensor bugs and have been around for a while..

So to sum it up. If you’re looking for an ambidextrous gaming mouse, buy a Diamondback 3G. If you’re looking for a right-handed gaming mouse, get a Deathadder. If you want the latest and greatest gaming mouse, wait for a firmware that fixes the bugs in the Lachesis.

To be fair, the Deathadder had some problems when it launched as well. Fortunately a few firmware updates fixed those. Let’s hope the Lachesis gets the same treatment and ends up being just as good as the Deathadder.

29 thoughts on “Razer Lachesis review

  1. Pingback: Arie’s blog » Blog Archive » Razer Piranha review

  2. While I was testing some drivers of its predecessors, I also noticed the reproducible BSODs.

    I forcefully terminated “razerhid.exe”, and after a while, the system suddenly crashed.

    Although I didn’t bother to investigate it any further, I guess its some invalid handle/pointer in the kernel driver, because user-mode code should not be able to provoke this.

  3. Well I work around it by taking razerhid.exe out of the general startup files using msconfig. I’ve put it in the startup folder of a single user.

  4. Hey Arie, do you have tested with the last firmware and drivers to see if the bug of sensors has been fixed ?

  5. I haven’t tested 1.75 (it only fixes unrelated problems), but 1.64 didn’t bring the Lachesis close to the Deathadder. The skipping and axis blocking were mostly gone, but the firmware introduced movement lag and still had the Z-axis tracking problems.

    I stopped bothering with the Lachesis late june when I sold it.

  6. Nice Blog Arie.

    As of October 31st the Lachesis has been given another firmware update: 1.91 which has fixed the jumping issue and some other problems.

    All signs point to it finally being good to go. A year after release.


  7. Yeah I read on Razer Blueprints that the new firmware is supposed to fix a lot of stuff. However, the Z-Axis tracking issue is not fixed, so I still consider it broken.

  8. you guys had any trouble with the startup of the mouse? mine is really random i dont get the jumping… instead sometimes i have to unplug it and plug it back in for the lazer to work… clicking works i just cant MOVE the pointer unless its disconnected and reconeccted…. really annoying.. im running all latest drivers and firmware…

  9. Well damn; I’m currently in the market for a mouse with more than the “usual” programmable buttons… and when I saw that the Lachesis offered buttons on left AND right side of the mouse, I thought I found it… until I saw you mention that you can only use 2 of the 4. *sigh*

    Got any recommendations of mice to check out that DO offer more? My current mouse has left and right click, mousewheel up, down, and center click, and two thumb buttons that I all use frequently… but I am looking for a mouse with at *least* 2 more (programmable in-game[warcraft] buttons) that isn’t as huge. I’d thought about trying out the new “made for wow” mouse, but the thing’s enormous and I have tiny hands so sadly that’s not going to work. Anyway, if you know of anything you could suggest that’d be fantastic! 🙂

  10. The Diamondback 3G has left, right, mousewheel, 2 buttons left and 2 buttons right. But those buttons are hard to reach/press.

    The new Razer Mamba has 7 buttons, but it’s very expensive.

    Maybe a Razer Copperhead would be nice. It’s very much like the Diamondback 3G, but it has better side buttons. I do think it’s End Of Life so it might be hard to get.

  11. i have no jump bug but i have another when i press the left mouse buttom and drag it it selects by itself and stops by itself and i am just holdibng the left buttom ?? help

  12. dude, the axis-lock is you pressing one of the side buttons with it set to profile switching. set it to mouse4/mouse5 instead using the razer software.

  13. @Daez

    the mouse buttons are all seperately programmable – for instance, I use the left front button as Ctrl-A, the right front as Ctrl-V and the right back as Ctrl-C, with the left back button set to a macro for photoshop.

  14. “No matter what DPI setting you use, the mouse is always using its 4000 DPI technology. The setting itself is just the translation of cursor speed on your screen. The mouse itself, however, is still picking up sensor abilities at 4000 DPI, which means that you’re still getting the advantages of its (4000 DPI) smoothness and accuracy, even if the setting is at 1800 DPI.”

    So your whole logic of setting it to 4000 DPI and lowering your in-game sensitivity is erroneous.

  15. No, you’re wrong.

    If you lower the ‘hardware’ DPI of the mouse, a game will receive less mouse inputs, which will force you to increase your sensitivity, which will increase the ‘gaps/angle’ of your crosshair movement.

  16. “Eh” just got served, i also get axis lock but this is after 3 hours of gameplay or so. I play counter-strike competitivley in leagues and playing the original version of counter-strike (1.6) i receive lots of random jumps as if the sensitivity got changed to 100000000 for 0.01 seconds and then back to normal. i get that like every 10 seconds if im unlucky but sometimes when i restart the computer it goes away. using 375-1000dpi ( i switch during gameplay ) 500hz ( tried 1000hz , no luck)

  17. having problems with my lachesis. but only when i use hard mat. it like it turns of for a second and then starts working again.. it does this almost every time i have to lift my mouse ? is this some kind of setting issue, the mouse or is this the mouse mat… its a steelseries mouse mat… works great with every other mouse :S

  18. Pingback: Arie’s Blog » Blog Archive » Razer Imperator review

  19. I got a Lachesis about 5 months ago. Best mouse i’ve ever used. Never had a single problem with it, I think its just cause you reviewed it when it first came out and its firmware was old and crap. I do recommend this mouse over any, including the Logitech G500.


  21. I am using Vista x64 with the Razer Lachesis. The problem is I have to keep reinstalling the driver because after a while the as I move the mouse it seems to lag and skip, it’s hard to describe. So to get into more detail, for example, if I move the mouse smoothly, the pointer will first move smooth then slow right down for no reason then speed up and do this multiple times in one mouse movement. I have never experienced this before. It is a pain in the a**. I paid £80 for this mouse. It does not even seem like Razer are even trying to fix their driver!

  22. I have the 5600dpi version, latest firmware and drivers. The mosue cursor would stop moving after a while, only solution was to stop the razer program running in the taskbar. Emailed support they are investigating, but not what i expected. usiong Windows 7 64bit

  23. @Brett, I got the same issue. Mouse wont move. Did there support team get back to you with a result?