dpi is upto you. But 800 is a good one for most, but kids speculating on what is the best DPI is mostly ignorance based on different expereinces.

800 is fine for most and all you need to know. Just use what feels right. It's that simple. 1600 is more than enough for anyone.
But a lot of the time its a numbers game mouse companies play.
OMG 10 millions DPI. Overclocking USB has best impact on smoothness.

USB can be overclocked on that mouse, though it won't hold 500 hz, so stick to 250 hz ..

In short, a 518 with 800 DPI and 250hz overclock will be a very good combination and won't max out the hardware running it at full dpi 24/7.

Finally, don't take the piss and ask for fucking proof. If you're that concerned do your own research and if you're lucky to come across someone as infomative as me you'll realise they'll tell you what I did.

It's fine at 500 Hz, it cannot go higher that 600ish though.

I had two of these mice and neither one exceeded 500 hz (when i tried it at 750hz) and in testing hovered around the 480's which is why I suggested 250 cos it'll stable and draws less from CPU and is a huge iprovement from 125, unlike 500 is compared to 250, does not max out your mouse or usb ports as over clocking with software is not without its risks.

I admit i am talking from my findings in 2005, so there could be newer programs or some hardware MOBO os, whatever might turn up inconsistincies, so I won't be so arrogant next time, but still stand by waht i said.

Overclock usb..

http://www.zdnet.nl/inter.cfm?id=42704&di...bmrs11.exe 31 KB&signature=BCB4612A4AB811626ACF8FDD368BCA23

Measure usb rate
http://tscherwitschke.de/download/mouserate.zip

Original post i did in 2005... (some good anwers)

http://www.esreality.com/?a=post&id=905276
+
http://www.esreality.com/?a=post&id=1240875

p.s peep'ss
if you ever want to find something on ESR use google, its seems to be better than the internal search one :/

Well let's be clear we're not talking at cross purposes. I think the MX518 I have here is the earlier model and it certainly gets up to 600ish Hz as reported by mouserate.exe, I'll screen cap it if that's what you're talking about.

"and if you're lucky to come across someone as infomative as me"

I lol'd.

I was truly offended by being asked for proof!
Fucking Brits are up their own arse a bit though I admit, but i blame the Romans.

You havent answered in neither of the questions anyway. I can get the same sens at 400 or 800 dpi and about the same at 1800, but its not the case read the question carefuly.

I know about that mouserate checker and the rate changer but Im not a technician or smth and i dont know how to test the performance on diferent DPI and rate properly.

OY get offended by asking a proof? Why are there ppl that say 500 hz on mx is fine?

For the last i dont find it informative at all.

500 worked on my MX500 and MX510, I'm seeing the same thing as ix getting about 600 only when trying to do 1000hz but 500 is ok.

Either way the difference between 500 and 250 is near the edge of what anyone can possibly notice. 2-3ms.