please please please help me with my PrescottHi there,

Hi there,
I just recently got all my PC hardware RMA'd back to me.
Right now I have...
Pentium 4 3.0GHZ Prescott
Abit IC7-Max3
Corsair XMS Twin X DDR400 (4 sticks of 512MB - 2GB)

So far, I've only got my overclock from 3.0GHZ to 3.5GHZ. This all tested stable on, Sis Sandra, Prime95, CPU-Burn In, high end games (BF2, HL2, etc.)
tested well over 10 hours on each program. But what I want to know is, why did I have to set my memory to 3:2 timing, instead of 1:1 in bios to make it
stable? If it was at 3.5GHZ and set to 1:1 it would crash at windows loading screen. My current settings in the bios is...
vcore: 1.61v
dram: 2.7
my agp/pci ratio or whatever is set to (fixed) @ 66/33
dram timings at: 3:2
think it was at 240mhz (3.5GHZ) I think

I just have a few questions if you guys could help me answer em, like what is the "NBSTRAP" in the bios? It has numbers like 400/533/800/667, I'm
guessing this is my FSB. So should I just leave it at "BY CPU" or "800"? I'm sure it doesn't matter right? Secondly, is my vcore to high? It's currently
at 1.61v, I didn't know how high to raise it when I OC'd so I just bumped to that number, should I lower it a bit? Also, right now I have 4 sticks of
Corsair CMX512 - 3200C2PT, but on 2 of the sticks, it says
XMS3202v5.1
0449107-5

And on the other 2 sticks, it says
XMS3202v1.5
0525066-1

Could this also be a conflict? When I e-mailed [email protected], he told me to set my ram at this speed
DRAM Voltage (also called DDR VOLTAGE): 2.75
--------------------
DRAM Clock: 200 MHz
SDRAM CAS Latency: 2.5
SDRAM RAS to CAS Delay (tRCD): 3
SDRAM Row Precharge (tRP): 3
SDRAM Active to Precharge Delay (tRAS): 7

So I did, I don't really know what this did, but I did it anyways lol.
And lastly, how high of an oc do you guys think I can achieve with the hardware I have mentioned above? I plan on hitting higher numbers, just want to
see what you guys think first. 3.5GHZ is ok for a Prescott, but I'm sure I can get it higher, cause 4ghz or bust!

Lower your vcore a bit, 1.6v is crazy for aircooling. Keep your memory at the same divider and go for 3.75ghz (that should be boarderline for air / 3.85.)

Oh, sorry, forgot to mention..I'm on air
I think I'll try 3.8ghz. Because, isn't it true that these Prescotts can reach up to 3.9ghz or higher? But thanks for the tip.

Definitely lower the vcore, 1.6v is way too high for a Prescott. I'd say 1.5v is about max. Maybe try something more like 1.45v for now. You might need to improve cooling a little if you want a good overclock.

Most of the newer stepping Prescotts will "generally" do 3.8 gig or more with good cooling, assuming all your components are high quality and play well together (of course your mileage may vary).

Just set the N/B strap for the default system bus speed of your CPU (which is 800). All this setting does is to make the memory ratios available that are typically used with 800 bus processors (1:1, 5:4, and 3:2).

The 3:2 ratio will run your RAM at a slower speed and 1:1 will probably not work at higher FSB speeds. I suggest you try using the 5:4 ratio which should be good for at least up to 250 FSB. Sometimes it's harder to O/C 4 sticks of RAM. For the time being and until you sort out your system, I suggest leaving the RAM timings on SPD (which automatically sets timings). We can tweak the timings later when you find the limits of your CPU/mobo. You can leave the vdimm at 2.75v like was recommended, no problem.

Another important thing to do on the IC7 series is to disable the last 2 game accelerator settings (on the same advanced BIOS menu as the RAM timings).

Hey thanks man, but may I ask why do I need to disable the 2 game accelerators, I'm going to do it anyways, just wanted to know why

And 5:4 ratio? Wouldn't that make my memory a lot slower and would I notice a difference really? I'll work around with it, and definitely lower my vcore.

Thanks a lot.

You know, I never was clear what those game accelerators did either, something to do with RAM timings I think. But, we learned long time ago that disabling the last two settings helped with stability when overclocked. I use auto, auto, auto, disable, disable while others sometimes use auto, normal, auto, disable, disable.

About memory ratios, 5:4 is faster than 3:2. For example, if you are running your system at the default 200 FSB, then 1:1 will run the memory frequency at 200 MHz (or DDR400). The 5:4 ratio runs the memory at 160 MHz (DDR320) while the 3:2 ratio runs the memory at 133 MHz (DDR266).

On the flip side, if you run 250 FSB using the 5:4 ratio, then your PC3200 RAM would be perfectly in spec at DDR400.

Oh jeeze, never did realize that, ok, will do.

Oh yeah batboy, so far, I've hit 3.60ghz on 3:2 and 1.51 vcore, your tips will help me get higher I'm sure, hehe.

hung said:

Oh, sorry, forgot to mention..I'm on air
I think I'll try 3.8ghz. Because, isn't it true that these Prescotts can reach up to 3.9ghz or higher? But thanks for the tip.

Click to expand...

yes that is quit true currently i'm at 4.05 ghz on air but i have posted as high as 4.4 then my memory decides to quit on me.

Ah, nice, and in your sig, was that value ram?
I should be able to hit 3.9ghz then.
Thanks guys.

hung said:

Ah, nice, and in your sig, was that value ram?
I should be able to hit 3.9ghz then.
Thanks guys.

Click to expand...

yep and it works better than my hyper x but soon i will have some new memory to play with.

hung said:

Ah, nice, and in your sig, was that value ram?
I should be able to hit 3.9ghz then.
Thanks guys.

Click to expand...

3.9... i beg to differ. you wont get past 3.7. those cpu's tend to max out at 3.7 on air anyway. cant get mine to go past 3.7 stable, and i am not on stock cooling. it works fine at 3.8, but will crash in a game. even have the occassional restart at 3.7 so its now back at 3.6.

Interesting...but how did sipherblade hit 4GHZ on his VR Ram? And stable too! Wow..lol.
2 hours on BF2 at 3.6GHZ hasn't crashed yet, so I might get lucky with my chip.
Btw, I'm on water.

jtracc20 said:

3.9... i beg to differ. you wont get past 3.7. those cpu's tend to max out at 3.7 on air anyway. cant get mine to go past 3.7 stable, and i am not on stock cooling. it works fine at 3.8, but will crash in a game. even have the occassional restart at 3.7 so its now back at 3.6.

Click to expand...

wow really thats great where did you get your facts at?? mabey from a cracker jack box so this whole time that my puter has said 4.05 i've been dreaming right!!!! thats great oh and i'm on air too but just because you can't get there everyone else that has MUST!!! be wrong well excuse us!! before you go spotting your mouth off about something you obviously Know crap about you should check your info.............for example http://www.ocforums.com/showthread.php?t=380373 and the cpu-z benchmarks are validated and also if your wondering mr. smartypants I was using an XP-90 and a vantec tornado fan. Well i think I proved my point now so I will leave you with this parting thought......... It takes more than just a proccessor to get a good overclock.

Damn sipher, chill out bro

jtracc20 said:

3.9... i beg to differ. you wont get past 3.7. those cpu's tend to max out at 3.7 on air anyway. cant get mine to go past 3.7 stable, and i am not on stock cooling. it works fine at 3.8, but will crash in a game. even have the occassional restart at 3.7 so its now back at 3.6.

Click to expand...

Dude, It's D0 vs. E0. E0's (which sipherblade has) overclock much better than D0's, We don't even know what chip Hung has yet. Hung, download CPU-Z and look in the "Revision" box to see if your chip is a D0 or an E0, E0's will do well over 4 Ghz if you have the right hardware.

TazExtreme3 said:

Damn sipher, chill out bro

Click to expand...

sorry.......(scampers off to the dark corner in his laboratory cluthing his EO and a rocket launcher screming viva la cheese!!!)

It's all good sipherblade.
Alrighty guys, looks like I got a E0! Woo hoo! Can I get excited yet, lol.
Ok here's the stats of my current OC

3.8GHZ
3:2 Ratio (Only doing 169MHZ on ram according to Cpu-Z, the heck?)
Vcore: 1.52v
Dram: 2.8v
Oh yeah, ram is 2.5-7-3-3 in bios right now.

So what I tried was 3.8GHZ on 5:4, didn't work, wouldn't stay stable, so now, I'm not sure what to do. Ocforums member "what" was telling me to set to 5:4 and try to get 200MHZ out of my memory, so at 3.75GHZ, my CPU/Mem is at 250/200. I tried that on 5:4 and 3:2, 3:2 only worked. which put my ram at a crappy speed. So now, should I go higher? And would it be more stable on 5:4 if I tried to hit 3.9 or 4.0GHZ? Tell me what you guys think, and thanks!

Ok, after a week, I've given up, so now, I'm at
3.9GHZ
179MHZ Ram (3:2) :\
Anybody know how i can get a stable OC at 4GHZ? Think some better ram is more appropriate.
Heh heh, who said Prescotts couldn't go past 3.7GHZ?

Better cooling and more voltage, in that order. Personally, I'd back off the O/C just enough to allow you to run the 5:4 ratio (might need to raise the vdimm a little). But I read where the 5:4 ratio don't work, so I'm at a loss. I do know the IC7 is sometimes a little picky with RAM. The IC7 also don't like tight RAS to CAS delay timings, so try raising that one notch (for example if it's 3, try 4).

mines at 3.7 at the moe.. 233mhz 1:1 3.4.4.8 im on water... still trying to get higher.. i know it will.. ive had it at 4gig but wasnt stable.. but it did boot up