The n810 has a 400MHz cpu, n800 has 330MHz cpu, and the DS has 2 processors, one at 67MHz, and one at 33MHz, this adds up to 100MHz of processor.

Isn't rule of thumb on emulation is you need 7x the processing power to make it decently playable? In which case you need roughly a 700MHz processor, which the N810 lacks.

At least that's what i seem to recall. Because they are both based on the ARM processor core that might help change it a bit, but i think the rule still applies.