i5-4590 over i5-4460

If this is for 'personal' use and other than moneymaking, then the calculation is fairly simple, since both CPUs are from the same system and generation.

The case clock difference is 3.2Ghz to 3.3 Ghz, which is 100Mhz or about 3% The Turbo Boost is 3.4 to 3.7, 300Mhz, but that's for one core. For two cores, the difference is 200Mhz, or 6%.

The cost of the 4590 over the 4460 is 10 in 150, which is a little bit more than 6%, so a bit more than 6% more expensive for a little worse than 6% improvement most of the time. Close to a push, but on the negative side.

I got my 4590 when the 4460 was $179, and the 4590 was $184. That was a good deal.

I've tested both CPUs, benchmarks clearly show the difference, everyday use, not so much.

 
Quick note on "perceivable" vs benchmark speeds as above ^, it takes about a 25-30% difference in speed for most people to notice that one thing is faster than another when it comes to how fast a system does something just by looking at it. So going from say 30fps to 35 fps is not likely to be noticed, but 30-40 or 30-50 would be. Anything under that point you get to "well, it may be faster, maybe not, or just a little, it's hard to tell".
 


My point exactly.

If this system is making money then even 1% is worth having. That's 20 more billable hours every year.