Those of you who have been around long enough will surely remember the co-processors that were around roughly two decades ago. As their names indicate, the role of the co-processor is to assist the central processing unit or processor in specialised tasks like mathematical computation; which could bring a CPU to its knees. The advantage of co-processors over general purpose processors is that they excel at doing particular tasks very quickly and very efficiently.
The trend for cheap available upgrades has taken a new turn thanks to AMD, Clearspeed and DRC computer. The former has developed a co-processor, the CX600, that goes in a PCI-x slot and is capable of performing 25 billion floating point operations per seconds, far more for example than AMD’s own server Opterons.
While it is expensive to buy, the CX600 offers an attractive return on investment due to the time and energy saved. The most interesting aspect of it though is that it can be easily installed into any general purpose server with a 64-bit PCI-x slot.
The second one, DRC computer goes even further by building a reprogrammable co-processor that fits in AMD's Opteron sockets straight away by just opening and putting the coprocessor(s) in place.
A server like the iWill H8502 barebone server would be able to hold up to seven programmable DRC modules and one Dual Core (or even Quad Core) Opterons, if needed. As for the above solution, the initial investment is quickly recovered by the savings in time and energy.
If your work field demands high computational power for crunching numbers and requires doing defined, specific operations very quickly, then you should definitely investigate the co-processor solution.