800 5-4-4-12 vs 667 4-4-4-12

[edberde]

I haven't put a system together in about 5 years, so some things are new to me. Here is what I'm thinking so far:

GIGABYTE GA-P35-DS3P 1333/1066MHz DDR2 1066
Intel Core 2 Duo E6850 Conroe 3.0GHz
Vista 64

For now, I'm going to buy 4G of mem and if all goes well w/Vista 64 I'll buy another 4G. (No sense buying 8G until I'm sure about 64)

Considering I will NOT be overclocking, should I go with:

GeIL Esoteria 4GB(2 x 2GB) DDR2 800 5-4-4-12 ($175)
or
G.SKILL 4GB(2 x 2GB) DDR2 667 4-4-4-12 ($170)

Since there is no overclocking, I would think that either would work fine on the 1333 Conroe. Would the DDR2 667 be faster since it has a Cas of 4?

Any help would be greatly appreciated.

Thanks!

- Ed

 

[TC91]

get the 800mhz ram, its only 5 bucks more. it has better timings for its rated speed, relatively, altho you wont notice the difference in anything other than benchmarks or memory intensive apps.

 

[edberde]

Ok, the 800 is definately a better chip, but I would have thought the 667 would be faster for my application. Wouldn't both chips only be running at 667mhz since my FSB is 1333? If so, wouldn't the 667 take one less clock cycle to return it's data?

 

[edberde]

Ok, I did some homework and saw a post by JustaGeek where he explains about DRAM/FSB ratio. If I understand correctly, this allows the Memory Bus to appear to run at a higher speed then the FSB. So does this mean that the 800 memory will actually run at 800, not at 667?

 

[TC91]

yah you can run ur ram at higher speeds than ur fsb by setting the appropriate divider. you could also under clock your 800mhz ram and tighten the timings, you should be able to get better timings @667 than those other ones since the 800 is a better chip. but overall the difference is very insignificant and you wont notice the change in timings or clocks in most apps, so it doesnt matter all that much apart from memory benchmarks and memory bandwidth intensive apps.

 

[JustaGeek]

With the timings being so similar, I would go with the higher clock, e.g. 800MHz.

It can always be underclocked to 667MHz, and perhaps the timings at 667MHz can be lowered to 3-3-3-10 or 3-4-4-12.

It is not guaranteed, of course.

Good luck!

BTW, pick the memory that runs at lower voltage, e.g. 1.9V is more desirable than 2.1V.

 

[taltamir]

Most chips are actually rated at different speeds... if you put the 800 chip in and run CPU z it will tell you the timings it is rated for at lower speed...

If your mobo is maxed out at 677 it might actually automatically set it to those timings... the 800 chip will give you better timings at 677 then the 677 chip would.