DDR 400 or DDR 500 overclocking

[RowdyRob]

I was thinking about getting getting an opty 165. And im pretty new to overlocking so go easy on me. If im taking the FSB up to about 280-300 MHz Should i get the DDR 500? Or am i missing sumthing.

 

[dvdpiddy]

yes you should and the reason is that the ht link on the proc is 200 so its perfect for ddr 400 but if you take the link up the ram loses cas latency but if you take the ht link up to 250 with ddr 500 then the cas will stay the same but with ddr 600 you can take it up the link to 300 and still have the same cas does that explain it a little bit

 

[admiral25]

I say get ddr400 and getting a good quality motherboard like DFI and you can get 300fsb/htt easy(most do 315). Im running 289x9=2.6ghz opteron 165, with a 7/10 divider (202mhz/404 dual channel rate)

 

[RowdyRob]

Well i dont want to divide that much. cus i want more performance from my ram. Looking at RAM overclocking there is alot to gain just like CPU overclocking.
If i get DDR600 RAM does my fsb HAVE to be at least 300MHz

 

[admiral25]

Well i dont want to divide that much. cus i want more performance from my ram. Looking at RAM overclocking there is alot to gain just like CPU overclocking.
If i get DDR600 RAM does my fsb HAVE to be at least 300MHz

If you say so... not a big difference from ddr400(5900) vs ddr600(7500)
thats with sisoft sandra memory benchmark. With athlon 64 and opterons are not like old p4 and athlonxp setup, with the northbridge or southbridge controls the memory flow. a64/opterons have there own onchip memory controler build in.

to each his own its like going from 1 gig of tight timing ram vs 2 gigs of lesser timing ram... its slower on benchmark program but real world 2gigs is far faster than 1gig, when you open more than 1 program. I have the ocz 2 gig 2-3-2-5 memory oced 2-2-2-5, and I tried there 1gig 2-2-2-5 but the 2 gig is much better for overall performace.

 

[RowdyRob]

Well im torn between OCZ Platnium Rev. 2 and a pair of DDR600's. Looking at the OCZ they have been clocked around the 600's before.

 

[WOWchamp]

If your motherboard has a memory divider function (most of the newer ones you buy sepereatly do) then you dont have to worry. The only case would be where you dont have a divider and want to overclock.

Lets say you had an X2 which is a stock of 10x200. You buy DDR500 (250x2) because you want to OC that CPU to 10x250=2.5ghz and your ram will be untouched and running at the speed its rated for. Just remember never to keep your HTT value between 1600-2000 for socket 939.

 

[dvdpiddy]

exactly what i said

 

[RowdyRob]

i understnad that. But what im saying that would it be better to overclock a DDR400 to DDR500. or just use DDR500.

 

[admiral25]

i understnad that. But what im saying that would it be better to overclock a DDR400 to DDR500. or just use DDR500.

I use a memory divider with my ocz 2-2-2-5 2x1gig set, fsb/htt 289x9=2.61ghz memory is running @ 202/404 mhz. For me to run 2.7ghz I do 300x9=2.7 with a 2/3 divider, the memory runs @ 200/400 mhz.

 

[RowdyRob]

i understand that, but i want my RAM to be at a higher MHz as well. And if i get a DDR400 and take it to DDR600 would it have better performance than ram RATED at DDR600

 

[admiral25]

i understand that, but i want my RAM to be at a higher MHz as well. And if i get a DDR400 and take it to DDR600 would it have better performance than ram RATED at DDR600

yeah, a little better performace, but nothing major like with older athlon xp / p4 systems. 2 gigs of ram is what gives you major performace with athlon 64/opteron computers vs high speed ddr1 600 memory.

Trust me I tried 1gig of ocz ddr 250 oced to 290mhz, and with dual core you need 2 gigs of ram vs high speed 1gig. Having dual cpus is like a car with 2 motors and you put put in 15 gals of premium gas... vs having 30 gals of regular... You would think that 15 gals of premium was better but its not, and it runs out fast. and dont try 4x512 because you will have to use 2t command rate vs 1t (1t gives you 5900 read speed vs 2t gives you 4700 read speed).

edit more info on what im talking about with link....

The integrated memory controller is still AMD's greatest advantage, Richard said. Integrating the memory controller allows that key link between the processor and memory to run at the speed of the chip, moving data into the processor more quickly than the front-side bus used by Intel's chips. Analysts and reviewers have consistently given an edge to AMD because of this feature, which Intel is not expected to duplicate anytime soon.

http://news.com.com/Intel+makes+performance+claims%2C+AMD+rebuffs+them/2100-1006_3-6043587.html?tag=nefd.top

 

[RowdyRob]

Ok then i guess i'll get a low latency, 1GB stick or DDR 500. Since its DDR 500 it will run more stable at a higher FSB than the DDR400 running at the same FSB.

 

[admiral25]

here is more info that shows you dont need to oc your memory on a a64/opteron processor


However, AMD got the approach to multicore processors right from the start, he said. Both cores can share the onboard memory controller and HT links - so avoiding the "gymnastics" of Intel's approach
and athlon xp

http://www.theinquirer.net/?article=29962