Heatspreading and by-SPD voltage dont have all that much to do with each other. In more detail:
- PC133 uses 3.3volts but since the clocks are low etc (old memory technology) it doesnt get hot
- DDR uses 2.5/2.6 volts. What this means is that manufacturers should report DDR400 memory (DDR400 chosen at random doesnt matter) the timings of the RAM at that voltage. So that means what you
should be seeing is "<Company> <Series> <Model> - <Speed Rating> with timings of <timings as given at 2.5/2.6v" or something to that effect
So, for a realworld example, we have (taken from
this memory),
Company = Patriot Memory
Series = Extreme Performance
Model # = PEP5123200LL
Speed Rating = 200Mhz, DDR400, PC3200 whatever
Timings = 2-3-2-5-T1 (very nice that they tell us it can do those timing at command rate T1)
Voltage = 2.5V
Now consider the very popular,
memory,
Company = Corsair Micro
Series = XMS
Model# = CMX512-3200XLPRO
Speed Rating = 200Mhz, DDR400, PC3200 whatever
Timings = 2-2-2-5 (we can hope that Corsair means this will run 1T but no 'guarantee)
Voltage = 2.8V
Now between them which would I take? Id prolly take the former because I know:
- By increasing the voltage you can push the memory harder. This means that by increasing vDimm, i can either push the clock higher or tighten the timings more -- or both
- Now I know (from expereince and a bit of techie sense), that with 2.5v memory i could probably run the former at 2-2-2-5-1T although worst case scenario i can bump to 2.6v and still have a 0.2v advantage
- Why advantage? The lower the voltage the lower tthe heat, the less stress yer putting on your modules and the more voltage you can add before you hit that 2.9v boundary (after 2,8v, you're on yer own) so that means i could possibly run the former at DDR466 with the same timings at 2.85V ... not so sure about the latter