iOS Cache Line Optimization

I have the follow struct in C++ on iOS, and am wondering if it is a problem, performance wise. I have been reading on cache line access and minimising them for optimal performance. I understand that on iOS, the newer chips have a cache line size of 32bytes.

I have the following struct in my app.

struct globalSynthParams
{
    globalVoiceParams       voiceParams;
    globalOscillatorParams  osc1Params;
    globalOscillatorParams  osc2Params;
    globalOscillatorParams  osc3Params;
    globalOscillatorParams  osc4Params;
    globalOscillatorParams  lfo1Params;
    globalOscillatorParams  lfo2Params;
    globalFilterParams      filter1Params;
    globalFilterParams      filter2Params;
    globalEGParams          eg1Params;
    globalEGParams          eg2Params;
    globalEGParams          eg3Params;
    globalEGParams          eg4Params;
    globalDCAParams         dcaParams;
};

When I run the sizeof() for each inner struct, it gives me:

Size of globalVoiceParams: 200
Size of globalOscillatorParams: 56
Size of globalFilterParams: 24
Size of globalEGParams: 24
Size of globalDCAParams: 8
Size of globalSynthParams: 688 (the total size of the above struct) 

Is this considered bad struct planning? Would there be any tangible performance improvement if I break up the structs such that they fit within a cache line or 2? I have checked the inner structs, they are packed nicely.

Some other articles I've read.. What is "cache-friendly" code?

Many thanks for your insights.

EDIT: In relation to the above question, what exactly am I doing when I am doing the below?

m_dAmplitude = osc3Params->dAmplitude; // osc3Params is part of the above struct

Am I loading the entire globalSynthParams struct into memory and accessing the osc3Params struct from there?