Another ? about Speex and CPU

Hello,

I am interested to use Speex but need to know If I can use it under  
our project's constraint. We need to use a low cost micro controller  
on a very small PCB. This means there's no space for an external DSP  
unit.

Can someone tell me if using an AVR32 (Atmel uc) which has a floating  
point calculation unit and DSP instruction set and running at ~50Mhz  
for a narrow band 8Kbps sampling rate maybe be feasible or out of reach?

AT32UC3C0512C:
Low Power 32-bit AVR® Microcontroller
– Compact Single-cycle RISC Instruction Set Including DSP Instruction Set
– Built-in Floating-Point Processing Unit (FPU)
– Read-Modify-Write Instructions and Atomic Bit Manipulation
– Performing 1.49 DMIPS / MHz
• Up to 91 DMIPS Running at 66 MHz from Flash (1 Wait-State)
• Up to 49 DMIPS Running at 33 MHz from Flash (0 Wait-State)

Or

An ARM7TDMI core running at ~50Mhz for a narrow band 8Kbps sampling rate?

I need to know this before I get deeper into Speex.

Thanks a lot!
Dominic Bazinet