Dram Ratio...what is better?

[Eastcoasthandle]

According to this link it indicates that 1:1 is the most desirable Dram Ratio for P4 (I also assume this is true for C2D as well).
So here is my question lets use PC6400/DDR2 800 & either P4-660 or C2D 6700 as an example:
Do you set Dram ratio according to your CPU (1:1)?
Or
Do you set Dram ratio according to your ram (4:5, 3:4, 1:2, etc) depending on what type you get?

I think I got that right...If you increase your ram faster then your FSB there is no noticeable gains when playing games...why?

[Burner27]

1:1 is most desirable. I do not believe there is a chipset out there right now that wil let you run DDR2-800 @ 1:1 (I could be wrong).
1:2 is worse than 4:5, 3:5 and 3:4. Do the math and figure out the percentages.

[Eastcoasthandle]

5:4 @ 400 FSB = 5/400 = 80*4 = 320*2 = Dram frequency of 640
(1.25)
OR
1:1 @ 400 FSB = 1/400 = 400*1 = 400*2 = Dram frequency of 800
(1)
OR
4:5 @ 400 FSB = 4/400 = 100*5 = 500*2 = Dram frequency of 1000
(.8)
OR
3:4 @ 400 FSB = 3/400 = 133.33*4 = 533.32*2 = Dram frequency of 1066.64 or 1067
(.75)
OR
3:5 @ 400 FSB = 3/400 = 133.33*5 = 666.65*2 = Dram frequency of 1333.3 or 1333
(.6)
OR
1:2 @ 400 FSB = 1/400 = 400*2 = 800*2 = Dram frequency of 1600
(.5)
---------------------------------------------------------------------------
Interesting...the better the Dram Ratio the less Dram Frequency you need. Hmmm....

[freecableguy]

Rule of thumb for Intel is 1:1 or 4:5 ONLY.

[Eastcoasthandle]

Rule of thumb for Intel is 1:1 or 4:5 ONLY.

thanks, that will answer my question...I take it that 4:5 is more for stablity purpose only. If you are stable at 1:1 keep it there (??)

[freecableguy]

4:5 is an up-divider....ie:

400 FSB at 1:1 is DDR-800
at 4:5 (400 * 5/4 = 500) is DDR-1000

just remember, FSB:MEM is the strap, so for every 4Mhz FSB the memory is 5Mhz up

[AndrewZorn]

So wait... are there any 'negative' multipliers? I want to get an E6600 to 4ghz on phase, but DDR800 costs a lot. There are plenty of DDR667 sets for $150. Is it really worth the extra money to get DDR800, as in, will it 'hold back' my overclock?

[mesyn191]

That is why I still like the AMD chips for OC'ing even though I went Intel for Conroe. No performance penalty for mem. dividers.

I'd go for the DDR800 Andrew, it'd suck to have a good CPU be held back by a bad memory OC. Its cheaper in the long run to try and do it right the first time. Trust me, you don't want to have to resell that DDR2 667 kit when it doesn't OC well, even if you only use it once you're gonna have to take a huge hit on resale value as it'll be used unless you get lucky and someone comes along and buys it off you for what you paid retail.

[Eastcoasthandle]

4:5 is an up-divider....ie:

400 FSB at 1:1 is DDR-800
at 4:5 (400 * 5/4 = 500) is DDR-1000

just remember, FSB:MEM is the strap, so for every 4Mhz FSB the memory is 5Mhz up

Gotcha...thanks

[Eastcoasthandle]

well some say it's a marketing ploy, I guess I understand them now...but I don't see that any different then AMD though

[freecableguy]

That is why I still like the AMD chips for OC'ing even though I went Intel for Conroe. No performance penalty for mem. dividers.

EVERY setting on AMD Opteron/Athlon 64/FX CPUs is a divider. I don't think you understand how it really works.

[lawrywild]

honk!!!!!!

[mesyn191]

EVERY setting on AMD Opteron/Athlon 64/FX CPUs is a divider. I don't think you understand how it really works.

I don't understand what you're trying to point out, I never said they weren't, just that you never have to worry about performance penalties with a A64 and mem. dividers.