The original Pi has plenty of processing power. It's just not in the ARM core, but in Videocore IV. Did your implementation or the library you used use VCIV? B

The original Pi has plenty of processing power. It's just not in the ARM core, but in Videocore IV. Did your implementation or the library you used use VCIV? Bear in mind VCIV can encode h.264 video 1920x1080 @30 fps. The architecture should be just fine for linear algebra, if 32-bit floats are enough for you. Raspberry Pi is a very misunderstood device and 95%+ of its true performance is going wasted if you just use it as a simple ARMv6 + VFP Linux computer.