hey, spaces come after commas, not before.

I installed Synapse to set the DPI to 400 and turn off the lights on the mouse and then uninstalled it and it seems the same to me.

I also have a g400 and I don't know what you're talking about. I think I had problems with the drivers for my beloved mx518 but not my g400?

installed synapse 400 dpi 500 hz uninstalled synapse all teh different mouse testing software shows lowest smoothing on those settings i honestlyh have no idea if other DA's are different

I have both mice, so here are my thoughts on your problem.
The issue you're experiencing with your G400 is because (at least, this was certainly true on the non "s" model), there are only two "true" dpi settings - 800dpi and 3600dpi. If you run the mouse at anything other than these settings, such as 400 or 1800dpi (both of which are default options for some reason) you'll have problems with jitter and shit which is probably what you mean by interpolation.
I found that the best setting for my G400 was 800dpi @ 500hz.

As for the Deathadder, the best setting was 1800dpi @ 500hz. No smoothing/tracking/jitter and the Synapse didn't cause any problems except for the fact that it's a stupid piece of software and was a colossal bitch for me to install.

Tbh out of the two I'd say the G400 is a nicer mouse when they're both set up properly. I'd say the worst issue you will encounter with the Deathadder is its bloodcurdlingly bad shape :>

"As for the Deathadder, the best setting was 1800dpi @ 500hz. No smoothing/tracking/jitter and the Synapse didn't cause any problems except for the fact that it's a stupid piece of software and was a colossal bitch for me to install. "

Is this the DA2013 version? Or older one?

Yes it's the DA 2013. It wouldn't detect my mouse at first and required two system restarts in order to get things going. Idk why. And I remember there were some problems with mouse spinning/smoothing initially too, but a firmware update fixed that.

I shall set my DA2013 to your settings (from 800dpi/100Hz)

Thanks.

lol agreed..I've already tried out the DA and it's shape is awful imo... but it tracks way better on 400dpi ,than the G400 did....
but I don't care... I'll just try using the Logitech on 800.
I'm gonna send the DA back and get my money back :> ...because of the shape.
I'm using claw grip and it is very tiring to hold this mouse firmly with my grip ..plus the rubber shit on the sides gets wet as hell very easily... and the whole thing feels cheap ,despite it's price being higher than that of the G400's or even the G400s's

Yeah, as I said the G400 doesn't natively run at 400dpi so it will be constantly trying to artificially emulate that DPI setting, which causes a lot of problems. It runs natively at 800 and 3600 DPI though, so you shouldn't experience issues - or at least I didn't. :P

The sensor on my Deathadder was actually great, but the shape is what made me give it up and go for a Kana v2 instead. When I had to grip the left side of the mouse it actually fatigued my thumb because the positioning was so awkward. I have pretty big hands and the Kana v2 (a much smaller mouse) is significantly more comfortable for me.

All this talk of sensors and jitter and smoothing and ideal DPI, the topic that gets majorly ignored with gaming mice is comfort. I guess because the quality of a mouse's shape (unlike the performance of a sensor) is not a tangible statistic and often comes down to personal preference. Well...whatever. :D

I use it with drivers, since my computer is also razer, and I havent seen any problem.