Can someone explain to me about OC, first question is how to calculate mhz in DDR RAM...

[stingbandel]

Hi,

Just setup my XP 2100+. I've been reading so many threads about people mentioning the DDR speed like 166 for the DDR 333 and 200 for DDR 400. Can someone explain to me how to calculate that speed or maybe you guys just set it up like that in order to get that mhz or something like that.

So far I only able to get the 144 fsb with the 13 multiplier with generic Samsung. I am thinking of getting the Corsair to get the max out of my system.


Another question is I also see the memory ratio that people mentioning and the CAS latency.

Can someone explain to me that? My mobo Asus A7V333 only has 1:1 and 4:5. How do I get the max on this?



Thanks


Darno

 

[lubetek]

first of all samsung is NOT generic. infact Corsair (which is what i have) uses Samsung memory modules. as for what speed you can run...well if u have pc2700 ram then u have DDR333. which means your ram runs stock speeds at 166MHz pc2100 runs at 133MHz. so if you wanna over clock it just up the FSB but you should go into your BIOS and adjust your memory voltage higher. then up the FSB in small increments till it doesnt run stable.

 

[stingbandel]

ok, thanks for the info. anyway, the highest fsb that I can get is only 143 with 1.825 voltage. does anybody know if there is any hidden trick to get more fsb?

I've seen people post up to 180 fsb with their xp 1600+. I was wondering if I could get 180 fsb.

thanks




Darno

 

[CrazySaint]

You will probably need to "unlock" your CPU so you can adjust the multiplier. Then lower the multiplier and increase the FSB.

 

[stingbandel]

mine is unlocked so I can lower the multiplier but the thing is I still can't go more than 143 fsb


Darno

 

[nemo160]

calculating the feffective clockspeed for ddr ram is easy, ddr stands for double data rate,so just take the true operating frequency (i.e.133 for ddr266/pc2100) and multiply it by two to get 266 effective operating frequency
pc2100/pc2700 refer to the bandwidth of ddr ram..pc2100 has bandwidth of 2.1 GB/s, pc2700 2.7 GB/s pc2100 is 133/266, pc 2700 is 166/333

 

[SupermanCK]

there are more math than just multiplying Buses by 2...since there are also FSB:MEM ratio if your mobo supports it or have that option...
so if you set your FSB:MEM ratio to 3:4..then you have to take your FSB, let say 100MHz, divided it by 3, which is 33.3MHz...and then multiply by 4, which result in 133MHz, effective DDR266 = PC2100 = 2.1GB/sec memory bandwidth.
of course there are more option under the FSB:MEM bus ratio...some board supports 3:5, 3:6, 4:5, 4:6...etc.

 

[stingbandel]

ok, so far I got 1872 with 1.85 volt and 4:5 ratio.


That's all I got. It's ok for now. stable but I haven't tested with prime or anything.


I will post again later on.





Darno

 

[Bakwetu]

You can also try and up the voltage for the ram if you can.