3 Ghz with DDR400 or 3.75 with DDR333

[tRaptor]

Hey, I'm still new to this whole DDR game and I have a question. I have a Asus P4P800-E Deluxe. I have been running my P4 3.0 stable @ 3.75 (15 * 250) with the ram running at 320 (not 333 some hardware limitation).

Well today i received some new DDR3200 (400) dual channel. Its great, but i'm not sure how to setup the system. I can still run with the 250 fsb, but only with the ram running at 320.

I know its best to get the ram to a ratio of 1:1 with the FSB. I guess i'm just wondering what you would do. I cant get the CPU to do 4 Ghz, i havent really tried anything above 3.75 at this point (except 4).

is there a good combo I can work with to get the best performence?

 

[stevty2889]

While P4's are extremely bandwidth hungry, and it's best to keep the mem at 1:1, I think you would lose a lot more performance, by giving up the 750mhz OC to run the mem at it's rated speed. It's definatly a bottleneck, I don't remember for sure, but there should be other dividers to run the mem at higher that 320 but still 400 or less to keep the mem from being OC'd. Actualy setting it to 333 in the bios is putting in a divider, so when you increase you FSB, the ram should actualy be running faster. Have you checked CPUz to see what you mem is actualy running at?

 

[Shimmishim]

what ram is it?

most pc3200 ram should be able to overclock somewhat.

so you should be able to run faster than 3.0 but less than 3.75.

but i think duvie's done a thread before showing 5:6 vs. 1:1. wonder where that thread is....

 

[tRaptor]

Thanks, I'll see if I can find the thread. Anyway, the ram is PATRIOT 2x512M D400 PDC1G3200LLK. The problem I have is I cant get the ram to even run at all when I have the FSB @ 250.

What I did was keep the FSB @ 250, set the ram to 400. It wont post when i do that. Is it a ram ratio problem? or is it trying to OC the ram? If i set the FSB @ 250 and then put the ram speed at "auto" i end up with the ram running at 266 (or was it 166) dam I can remember now....

What I wish i could do was set the fsb at something like 225 (maybe less maybe more) and keep the ram running at 1:1 ratio, I just cant figure out how to get the board to do it.

 

[GuitarDaddy]

With FSB @ 250 and ram set to 400 (1:1) your ram is overclocked to 250mhz (DDR500) which that ram can't handle. I would try lowering the CPU multi to 14 and running 268x14=3.752mhz and set ram to 333, this would give you a ramspeed between 200-220mhz (DDR400-440) your ram should be able to handle this with a bump in voltage and or relaxing the timings.

 

[tRaptor]

Ah, i guess I just thought it was the ratio making it not run. That makes sense. Does Intel allow lowering the multiplier?

 

[Shimmishim]

no. you can't unless you are using a prescott and the p4c/p series asus board with the 1014 bios which allows you to go to a lower mult.

3200LLK is pretty good memory...

default timings 2-2-2-6? if it is then it should have samsung tccd modules on it which allows for higher fsb overclocking... but it'll require you to lower your timings from 2-2-2-6 to 2.5-3-3-7. try that i'm sure it should boot at 250 1:1 (400). i haven't heard of tccd or tcc5 that hasn't been able to do at least 250.

 

[tRaptor]

Actually the default timings are 2-3-2-5. I might try something like 225 FSB now that I understand how the ram overclocking works