[b1029384756]

I have an Asus P4C800-E Deluxe, currently using a P4 2.6C (probably will be swapped for an EE eventually), and I have it running at 3055 MHz (235 FSB). I can't do 240 FSB, because Prime95 gives me errors, although I can manage 250 FSB and play UT2K4 and Doom 3 with no apparent problems. I use a 5:4 FSBDR ratio because above 220 FSB, I get programs crashing if I use 1:1. My vCore is currently set at 1.6V. It seems to handle that fine, but when I try 1.625, it won't even POST. I don't even get any beeps or anything upon trying to boot. At 1.6V, my CPU is currently running at 113 degrees idle, 140 degrees load. That's a bit hot but I should still have some head room. I picked up a Thermalright SP-94, a 92mm Vantec Tornado (I love that thing, really powerful), a Swiftech MCX-159, and Microcool heatsinks for southbridge, PLLs and MOSFETs, so I'll put them on when I get a chance, since right now I'm still using stock cooling. Anyone know why I can't POST with 1.625 vCore? I'd like to try 1.65 vCore and see if I can't hit 250 FSB stable that way. I'm pretty new at this, so if you think I'm doing something wrong, let me know.

[baltoos]

Those temps translate to 45°C Idle & 60°C Load. those are rather high , so I'd suggest getting your cooling mods done ASAP!!

What kind of Memory are you running?

I have a 2.8C Northwood on a P4C800E-Dlx. w/ V-Droop & V-DIMM mods running 1GB of OCZ PC4200EL. It's currently running at 270FSB (3.78GHz) with memory at 1:1. V-Core is at 1.504V. RAM timings are 3-4-4-8. More info & pics of my rig are HERE. The absolute HIGHEST LOAD temp I've seen with this rig is 45°C.

I believe something is holding you back, most probably your RAM.
I'd suggest not going higher than 1.6V for your V-Core. From what I've seen about the notorious Asus V-Core Droop problem, the 1.6V V-core setting in BIOS has the least voltage drop under load than any of the other settings.
Go too high on your V-Core & you might run into the Dreaded Sudden Northwood Death Syndrome.

I'm thinking that, maybe with some better memory, you could get significntly more out of your Northwood.

-Dave

[b1029384756]

I actually had the load temp wrong, I didn't know you need to run two instances of Prime95 for full load with an HT P4. With that, the load is 145°F (63°C). Shouldn't that be acceptable, since the 2.6C is rated for 75°C? I'm using Corsair TWINX1024-3200C2PRO. I'm about to trade that for the TWINX1024-3200LLPRO, though. It'll only be 2-3-2-6 as opposed to 2-3-3-6, but since it's an even swap for me...it's worth it as it costs me nothing. I don't know anyone with spare sticks of 2-2-2-5, and I don't want to spend to buy a gig of that, so I'm pretty much stuck with the RAM I have, maybe I should try to add vDimm? I don't mind running 5:4 as much as that it seems the CPU itself is limited to 235 FSB, so why shouldn't I boost my vCore to try to go for 250? It seems most 2.6C's are capable of at least that and then some, and I'm willing to take the risk of frying it since they're relatively cheap nowadays. I'll try with better cooling, but I'd still like to know why I can't even POST with 1.625, at any FSB.

[baltoos]

Even tho your CPU isw rated to 75°C, IMHO, 63°C Load is too high. I think you should try to keep your CPU temps below 55°C. I strongly suggest you get your cooling improvements done ASAP!!

If your system is not booting above 235FSB, I believe something else besides V-Core is holding you back. I suspect your RAM doesn't want to run very aggressive timings at much above stock 200FSB.

I'd suggest setting V-Core to 1.6V & leave it there. It's been my experience that when you're near the maximum limits of your Northwood, raising V-Core will not give much of an increase in speed. Raising V-Core will rapidly raise your CPU temps.
Set RAM at 1:1 or 400MHz in BIOS & timings to 3-4-4-8. Don't worry, Intel rigs aren't anywhere near as sensitive as AMD rigs to RAM timings.
Set V-Dimm to 2.85V & see how far beyond 235FSB you can go. Raise FSB just 1 or 2 Mhz at a time till you find the limit. Next, set RAM to 266MHz (2:3) & slowly raise your FSB. This way you'll find the limits of your CPU.
Also make sure your AGP/PCI is set to 66/33MHz.
Best performance will probably be at he highest FSB you can run with RAM at 1:1.
If you find your CPU can go above 250FSB with RAM at 266MHz., try 333
MHz (5:4) & see how it performs.
Good Luck!

-Dave

[ciku]

Baltos, cant you lower your timings? thats a great ram running at poor timings...

[baltoos]

I'll get occasional errors at 2.5-4-4-8 & anything lower than that it won't boot.
Remember tho, I'm running it at 270FSB at 1:1.
SiSoft Sandra benchmarks were only very slightly lower at these timings - Right near 6300.
-Dave

[b1029384756]

I appreciate your advice, but I don't think you understood what I was trying to say. Basically...

220 FSB, 1:1 FSB/DDR, 1.55 vCore, completely stable.
225 FSB, 1:1 FSB/DDR, 1.575 vCore, certain games tend to crash, obvious memory problem after using Memtest and Prime95 and changing ratios.
235 FSB, 5:4 FSB/DDR, 1.6 vCore, completely stable
240-250 FSB, 5:4 FSB/DDR, 1.6 vCore, nothing crashes but Prime95 reports errors. Since the RAM is running at 200 MHz at 250 FSB, the RAM is fine but the CPU isn't.
At 1.625 vCore, I can't POST, at _any_ FSB or FSB/DDR ratio. I tried stock speeds at 1.625, it just doesn't work. Even if I shouldn't raise the vCore that high as a long time solution, I'd still like to know why it won't even boot, at _any_ stock or overclocked speed.

Also, if anyone knows why the CPU won't go higher, I'd love to know how to fix that...I use 66/33 AGP/PCI lock, using 2.75 vDimm now. It doesn't seem to like 2.85V (also won't boot). Could it be an inadequate power supply? It's an Antec TrueBlue 480W, I thought Antecs were high quality without paying $500 for PC Power and Cooling or something like that. I tried 238 FSB, also unstable, Prime95 reported errors after 20 mins. I'm not gonna bother testing for 236 or 237 for now.

[baltoos]

Your PSU should me more than adequate. What does do if you try 225 FSB, 1:1 FSB/DDR, 1.55 vCore?
All I can think of is that your CPU does not like the ~60°C load temps, or that you RAM is right at its ragged edge at stock timings & 200FSB.
Have tried manually setting looser timings, say 2.5-3-3-6?
My 2.8C is completely stable at 270FSB & 1.5V. I've run it at 275FSB with same voltage & it's almost completely stable. The only problem is that if I go above 270FSB, It will hang on restart & won't boot. If I shut it down completely, there is no problem. Weird!
-Dave

[Kiriakos]

Here is the FIX .

New BIOS 1023
READ this .

http://www.ocforums.com/showthread.php?t=398120

[MrSeanKon]

Originally Posted by b1029384756

I can't do 240 FSB, because Prime95 gives me errors, although I can manage 250 FSB

I have the same mainboard and in winter it reached 270MHz FSB without modding.

Originally Posted by b1029384756

why I can't POST with 1.625 vCore?

Cos Intel RULEZ!
I have tested 4 Intels (1 Northwood Celeron, 1 Celeron Prescott and 2 P4 Prescotts) and all could not boot with Vcores>1.650 in BIOS.

This mainboard undervoltages Vcore (I use multimeter).
Look here for multimeter usage.

Download here Throttle Watch it's freeware must have for Intel users.
More o/c tools are here