What CPU should I buy?

[Tomasmccann]

I run Windows 7 with an SSD, 8gb ram and a GTX650 2gb graphics card with 3 monitors.

CPU currently is AMD Phenom II X4 945.

Having FL studio with more than one Serum and iZotope Ozone VSTs + multiple unisons strains the CPU too much even at the highest buffer size, my previews are often ruined by the heavy stuttering. Not to mention that big a buffer is pretty inconvenient for midi key input, it has to be decreased every time I need to record midi. My budget is $400. What CPU would you recommend?

 

[THA_REAPER]

Kind of hard to answer. I don't have much experience with AMD, but you need to take into account the socket on your motherboard and can you get a significant upgrade due to its specifications. I don't think the upgrade will be huge, but just doing some reading and searching you have a AM3 socket. Only upgrade I see is the AMD Phenom II x6.
ASRock > Support > CPU Support List

If you want more options you may need a newer motherboard. Which isn't really expensive imo just slightly raising your budget. I recommend the i7 4th and 5th gen processors, but that'll mean switching to intel. The processors should come in just under $400. If you switch make sure its a motherboard that supports your ram type DDR2 or DDR3? Also your PSU is compatible and meets requirements. I compared my current cpu which im happy with and had about two years to your current. I used serum and ozone as well.
http://cpuboss.com/cpus/Intel-Core-i7-4770K-vs-AMD-Phenom-II-X4-945-95W

I also want to say that Serum is not light on resources and Ozone is a CPU hog with most CPU's. Ozone isn't really intended to run on a fully loaded project with various effects or soft synths. You can but it'll cost you more cpu usage.

Just wait for others to post who may possibly have better suggestions.

 

[BlackTee]

i say a AMD FX 8350 or Intel 4790k