@kalm_traveler You could OC E8500 to 1600MHz FSB (especially on P5Q3). 1600MHz is like nothing compared to how high it should be able to go.
However, if you didn't, on 1333MHz you couldn't set 1600MHz on memory (the required multiplier simply isn't there).
@dr_st I better explain how I think about this, before we go further 😁
Here's how I see this :
1MHz real clock = 2MHz effective clock (that's for DRAM speed [it's like this since DDR1]),
1MHz real clock = 4MHz effective clock (that's FSB effective speed [or "Quad Pumped Bus"]).
Based on that, limits for Intel chipsets are :
Max. effective DRAM speed = effective FSB speed (that's 1:2 ratio [FSB:DRAM], for real clock, [or "2:1" if you think "DRAM:FSB"]).
Min. effective DRAM speed = 1/2 effective FSB speed (or 1:1 ratio, on real clock).
I always use REAL clock ratios to do math for speed.
If you own nVidia chipset, you should be able to go lower than 1:1 ratio on minimum side (I think it's 1:0,8 on FSB:DRAM [?]), however max. effective speed is still locked to effective FSB speed (IIRC).