[Q] Searching ROM for unknown f900 tablet topic

Hello,
my sister´s girlfriend got a strange tablet and asked me, if I could make it faster/more responsible.
I would really like to help her although it´s a ****ty piece of hardware.
A little googleing showes, that it looks like a "MaPan MX 913". But the specs doesn´t :(

Android System Info says:
Andoid version: 4.0.4
Release Codename: REL
API LEVEL: 15
CPU ABI: armeabi-v7a
Hardware: sun5i
Board: nuclear
Brand: softwinners
Device: nuclear-f900
Display: f900-dbl_V1.1.7_20130122p_r587_27d8028
Fingerprint: softwinners/nuclear_f900/nuclear_f900:4.0.4/IMM76D/20121225:eng/test-keys
Host: brn-zhengshenxing
ID: IMM76D
Model: Softwinerf900 <-- no typo
Product: nuclear_f900
Tags: test-keys
Type: eng
User: zhengzhenxing

The screen resolution is 800x432 :-/

Has anybody a clue, who build this thing and - more important - how to root it and where to get a better ROM for it.