How do I make Quartus II compile faster

Some useful flags to make Quartus synthesize faster if you don't care about fully optimizing your results and just want to get a pessimistic estimate or do comparisons.

set_global_assignment  -name PHYSICAL_SYNTHESIS_EFFORT  FAST

Specifies the amount of effort, in terms of compile time, physical synthesis should use. Fast uses less compile time but may reduce the performance gain that physical synthesis is able to achieve.

set_global_assignment  -name FITTER_EFFORT              FAST_FIT

Fast Fit decreases optimization effort to reduce compilation time, which may degrade design performance.

And instead of execute_flow -compile, use:

execute_flow -implement

Option to run compilation up to route stage and skipping all time intensive algorithms after.

In a meeting with Intel/Altera engineers, using -implement this was ball-parked to be about 20% faster than -compile, and came recommended when iterating on timing-closure results.

You could also try the following:

set_global_assignment  -name SYNTHESIS_EFFORT           FAST

Note: This has the caveat below, although I tend to see overall faster runs in some designs.

When set to Fast, some steps are omitted to accomplish synthesis more quickly; however, there may be some performance and resource cost. Altera recommends setting this option to Fast only when running an early timing estimate. Running a "fast" synthesis produces a netlist that is slightly harder for the Fitter to route, thus making the overall fitting process slower, which negates any performance increases achieved as a result of the "fast" synthesis.

Edit:

The below settings will punish your timing, but they can also help with compile time significantly, particularly on newer Stratix 10/Agilex designs:

set_global_assignment -name OPTIMIZATION_MODE          "AGGRESSIVE COMPILE TIME"
set_global_assignment -name ALLOW_REGISTER_RETIMING    "OFF"
set_global_assignment -name HYPER_RETIMER_FAST_FORWARD "OFF"

And you can also turn off timing analysis with the below:

set_global_assignment -name TIMEQUEST_MULTICORNER_ANALYSIS "OFF"

In order of decreasing important.

• More memory. 4 GB for a 32-bit OS. Some designs need more that that and require a 64-bit OS.
• Don't overconstrain the design.
• Change the compilation options to not try as hard. That's under assignments> settings> Fitter Settings>Fast Fit (or Auto Fit)
• 8.1 supports multiple cores.
• Hiearchical compiles help, especially if you have multiple instances of the same block.

2 minutes is really short, I agree with the previous poster. A single gate will that take long.

Some things:

• If you're not putting it on an FPGA, why compile with Quartus ? Just simulate it with Modelsim or ActiveHDL or whatever simulator you have.
• 2 minutes is a very short compile time. Really :-)
• Try Quartus 8, it's much faster than 7 and older
• To check that your code synthesizes correctly and see the netlist, you indeed don't need the fitter and assembler steps