question about 2x2gb ddr2 kits

[TC91]

Can 2x2gb ddr2 kits usually hit slightly loosened CL 3 timings (~3-4-4-12/15 ish) timings @ ~800mhz?

 

[n7]

Basically, no.

I have never seen a single Powerchips-based 2x2 GB kit run CAS 3 @ DDR2-800
And pretty much every decent 2x2 GB kit is Powerchips.

If you find some old Micron-based 2x2 GB kits (old Mushkin - D9GSV or some old Crucial - D9FTB) & pour voltage into them, perhaps, but even that's unlikely.
With old Micron as i mentioned, you'd do 4-3-3 with reasonable voltage; 3-3-3 would take killer vdimm.
And you'll never be able to run 24/7 then as it'd take far too much vdimm.

2x2 GB is strongest/fastest @ higher speeds CAS 5.

So use a higher than 1:1 ratio (think 5:6, 4:5, 2:3, etc.) & run DDR2-1000-1200 CAS 5.