So, the Intel Core 2 Quads and X54xx series Xeon Quads fall into the same CPU compatibility issues as the AMD Phenom series, but as with the Phenoms...
Realistic expectations need to be set.
If your Core 2 Quad or Xeon Quad is hitting the approximate CPU frequency for the suggested low end i3/5 Quad (I.e., about 3.4 Ghz and up), you would be fine in Apex.
Important: ^ This only applies if you are pairing the above CPU:
- With a capable recent GPU (I.e., GTX 1060/1070/Rx 570/580/590/Vega etc.).
- With sufficient VRAM (4GB and up) and main system RAM (8GB and up).
You're good to go when these baselines are met. You are already playing the likes of PUBG and Blackout right now at 1080/High/60fps and up.
Despite the release date of these gaming CPUs, several models were always strong, they've aged well, and you still qualify as having a "gaming rig" today.
In fact, you're knee deep in AAA games released in 2018-19 and they're playing well on such CPUs, just like Apex would play well.
However: I see some passionate people on the Phenom thread, and we see they have - for example - only 4GB of system ram, or they're using a dated GPU featuring only 1 to 2 GB of video memory.
Sorry, but even if the game was patched to distribute instruction set compatibility for your AMD or Intel CPU -- a PC like the weak one above was never going to meet the Apex spec regardless. Yes, it would still be nice to actually load into gameplay and decide that for yourself, but some baseline speed and RAM numbers are simply impossible to overcome.
The folks on faster, higher end Phenom and Intel Quad rigs combined with excellent GPU/memory specs, however, these guys are absolutely, provably ready to play a sophisticated modern 'AAA' PC game. They're already doing it, and if Apex patched-in retrocompatibility for SSE registers, they'd be playing/spending in Apex too.
TL;DR for the OP: Unfortunately your Q9300, considering the low cache and low 2.5Ghz clockspeed, was never going to run Apex well anyway.
Not at any acceptable gameplay performance. It overclocks to 2.8Ghz-3.0Ghz easily enough, but runs hot.
And that still misses the mark for Apex. Tossing more GPU at it wouldn't help much either.
(Btw: All the Intel Q and X54 models on socket 775/1 support MMX, SSE, SSE2, SSE3, SSE 4.1, Enhanced Intel Speedstep (EIST), Intel 64, XD bit, iAMT2, Intel VT-x, Intel VT-d, TXT).
