Did you not get my reply over at myG37? Anyways here goes
Increasing the Compression Ratio in an engine will generally increase your engine's thermal efficiency ie you'll exctract more HP/TQ out of the same amount fuel (you're basically squishing the air and fuel molecules in a tighter space which makes them react better). That being said, you'd require less boost to achieve the same numbers you'd achieve with lower compression and higher boost since the higher compression engine would be a "better platform"
However, it's a double ended sword
An engine with high compression means that it would be more prone to a phenomena known as engine knocking under boost, and that is when the air-fuel mix combusts prematurely ie before it hits the "Top Dead Center" which it shouldn't. (Read about a 4 stroke cycle or the otto cycle on wikipedia or howstuffworks if that didn't make any sense.) To overcome that knocking, methanol injection would need be introduced and sometimes the use of race gas with high octane numbers along with ignition retard. (I strongly recommend you read a lot about those before considering getting boosted)
Also, high compression ratio means that the combustion chamber will be at a higher pressure at the top dead center. That highly pressurized area will be is confined by:
1) Part of the engine head
2) Closed Intake & Exhaust Valves, 4 per cylinder in our case
3) Part of the combustion chamber's wall
4) Piston head
Each one of those components will transmit the force to whatever's holding it in position till the weakest link fails basically. (Piston Head -> Connecting Rod -> Crank shaft for instance)
Now imagine that high pressure goes on and off 10,500 times in your engine when you're at 7k rpm. That's why there's only little boost an engine could hold before going kaboom, and that is why many drop their engine's compression ratio when going with crazy boost, even if it had to be at the price of reduced thermal efficiency.
Hope that made sense and happy modding