4x2G kit vs 2x(2x2G) kits is an irrelevant difference.
The only even conceivable slight benefits are you could save on shipping costs by ordering one product vs two,
one or the other of the options may be less expensive, and if you decide it isn't good and want to return it all you have one 'product' to return vs two.
As long as they're the same model by the same manufacturer the sticks will be as compatible as you could expect them to be in either kitting case.
PC chipset doesn't really matter, there are some good boards with any of those chipsets, just as there are some bad/worse boards with any of those chipsets. Read the reviews and support forums for the motherboard model you're researching and find out what kinds of problems people have with it. Typically it'll be BIOS bugs, maybe some bad drivers or bad / slow support issues on the OEM's web site, maybe some quirks / problems with the specific hardware due to their PWM power circuits or PCB layout, heat problems due to the way they heatsink stuff, etc.
The chipset shouldn't generally matter a huge deal to 8G RAM compatibility, though some motherboards due to their better BIOS options will give you more CONTROL of the RAM timing and other parameters than others BIOS implementations will.
Don't even THINK of buying 8G of DDR3, in no way, shape, or form is it a significant performance benefit, or cost / performance effective versus quality DDR2 DIMMs. With $55-$100/2x2GB level prices for lifetime warranted high quality reputable products you just can't go wrong buying 8G of good quality DDR2 in the speed you need.
I've built 4 systems with 8GB DDR2 so far on various P35 chipset motherboards (ASUS P5K-E, P5K-DELUXE, ABIT IP35-E), and have used anywhere from old PC2-4200 RAM, PC2-5300 RAM, PC2-6400 RAM from three different vendors and several different models of RAM from those vendors, and I've had next to no problems. I've encountered one DIMM out of the 16 that was defective on arrival but 24 hours of memtest86 with the system at stock settings caught that problem and now I'm replacing the bad DIMM.
Anyway the point is you can get 8GB working very easily with most any decent quality motherboard with a decent quality BIOS and with decent quality even low end RAM sticks.
If you're getting PC2-6400 speed, look for DIMMS that run 4-4-4-12 or 5-5-5-15 at a manufacturer specified voltage of 1.8 or 1.9V ideally. I suppose it wouldn't be too bad if the 4-4-4-12 stuff was rated at 2.0V since it is faster.
If you're getting PC2-8000 speed, look for 4-4-4-12 (much more uncommon / expensive) or 5-5-5-15 timings at any voltage from 1.8-2.1V manufacturer specified.
If you're getting PC2-8500 speed (few people really have any benefit from it, though, and it is usually much more expensive in this quantity), any voltage from 1.8-2.2 is acceptable and any timings from 4-4-4-12 (almost impossible) up to 5-5-5-18 or so are worth considering.
Look for lifetime warranty on the DIMMs from the manufacturer and good reviews of their products.
As for OCability well you can OC the main system clock to 400 MHz with PC2-6400 *without* OCing the RAM. You can OC the main system clock to 500 MHz with PC2-8000 RAM *without* OCing the RAM. So if you go higher than those clock values for the base system/CPU clock, then you'll OC the RAM too.
There's no real way to predict how a given chipset motherboard / RAM DIMM / CPU will overclock, some are much better than others, luck, and a lot depends on the actual mix of power supply + motherboard + BIOS & its settings + CPU + RAM as to how exactly you'll be able to OC. Usually a lot of reputably decent OC motherboards will hit 450MHz-480MHz or so and beyond that really depends on your exact system configuration and luck; some get to 535 or so but that's pretty lucky.
CPU OC just depends on your CPU/motherboard/BIOS settings and the CPU multiplier in effect and your luck with that hardware.
Some RAM DIMM models are better OCers than others, generally the lower the stock voltage and the faster the stock speed the DIMM has the more room it has to OC beyond that level, but even so some chips/DIMMs are much better than others. Read the reviews of particular models to see what people usually get.
Originally posted by: koshling
Does anyone have a handle on the factors likely to promote better stability (or even o/c ability) in a scenario with all RAM slots occupied (8G, Vista 64) [assume 45nm quad, probably 9450] ?
Some specific questions:
1) 4X2G kit significantly beneficial over 2 X 2x2G kits (of the same type) ?
2) Is the choice of chipset (between X48,X38,P35) likely to impact this significantly
3) Are the issues any different with DDR3 than with DDR2? Any stability benefits in this scenario to going DDR3?
Thanks for any advice anyone can offer.
