Update: P5B Vanilla (16Feb2007)

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Originally Posted by dnottis

I picked up the deluxe from Newegg, working great except for the 1x/16x PCI-e issue, but there is a workaround and that is working.

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What revisions is yours and how long ago when you bought it?

I regret to have to say this, but the spread spectrum theory I had was completely off. After a few days of usage, I found it to be instable still, although it still was able to occasionally boot at 500fsb.

I found that when it didn't boot, if I powered off from the button instead of psu, waited 5 seconds, then tried again, it'd boot and work fine until it next needed a reboot.

After much more fiddling, I've found out what the issue is, although I haven't found a solution yet.

The p965 boards all seem to be plagued with "false boots" sometimes, where it'd turn on, then turn off, and back on. This happens only some of the time, and for 400fsb, the false boot isn't necessary. On the asus website, it says that this false boot is because of something needed to trigger the southbridge on.

The problem is that at 500fsb, my p5b requires this false boot every single time in order to post. I've found that when I initially switched VT off, it'd false boot pretty much everytime for the next few reboots. My initial testing must have had testing with spread spectrum on while it was false booting. then when I switched it off, it was a coincidence it didn't do it. Then when I switched it back on, somehow it decided to do it again, and thus work.

So it looks like I'm able to get 500fsb on my p5b now predictably. I can keep vnb, vfsb, vsb at stock values. However, I need to increase vich to 1.215v.

I've found stability (tested with 6x multiplier and loose timings to just make sure of 500fsb). However, the problem is that if the computer is to be rebooted, it may or may not post again, depending on if it decides to false boot or not.

If it doesn't post, I just hit the power button, let it sit 5 seconds, and it'll guaranteed post. It's too bad this isn't acceptable, since it'd mean I would lose contact with my computer if I was away and needed to reboot it, or it were to otherwise crash on it's own and reboot.

I wonder why the southbridge requires this sort of triggering, as Asus put it, and what I can do about it. I see that 1.215vich is already above what intel states as the max for it, so I don't know what to do.

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Originally Posted by ziddey

Good buy!

edit: Also, it should be noted that the cpu reading is way higher than what it actually is. Coretemp reports about 47'c under load for me, which is about what it's been with two other boards I've used. Meanwhile, asusprobe reports 62'c.

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thanks ziddey, that's what i really want to know. I was really worried about the temperature probe2 was displaying!

Looks like I can also join the 500+ fsb club!

http://www.overclock.net/attachments...g?d=1175754802

http://valid.x86-secret.com/show_oc?id=184252

Hmm... haven't tried raising SB voltages yet, wonder if that will help me get >380fsb... (I'm starting to get desperate - thinking long hard about eBAY all this junk)

The Coolest's reply in the other thread you posted in was spot on. Have you tried that yet?

Hey ziddey,

I tried some of the suggestions:
1. upped vcore to 1.5,
2. upped Vsb and Vih
3. upped all other voltages, and turned Spread Spectrum off.
4. PCIE 105Mhz.
5. even tried re-arranging power cable.. using other 12VATX connector, and other video card PCIE connector...

with 6x multi, got me up to 390fsb, barely. 401, 410, 420, do not POST. And as I said earlier, the memory can do at least 900, so its surely not the problem.

first, running stock (2.13Ghz), the BIOS shows CPU temp ~50C, and mobo temp ~40C... strange... high?
Using Intel Thermal Analysis Tool, it was ~40C idle when overclocking, but still concerned about the northbridge. While in BIOS, I held my finger on it, and it got at least up to 60C.. could barely keep finger on there.. .is this normal?

cpuz shows 6x390=2340Mhz
but coretemp shows 6x520 = 3120!! well if its "really" running 520fsb even though I set 390 in bios, that would explain why I cant go higher.

coretemp doesn't read fsb properly.

as for nb getting that hot, slap a fan on there to cool it down, and see if it helps you go further.

Check out other thread ziddey.. it was the CPU. CPU has fsb limit too (apparently).

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Originally Posted by ziddey

Update. I've found vdimm pencil mod for vanilla board.

I may not have the same revision as you guys based on the pictures I've seen compared to what I've seen but...

Under my RT9214 IC, I have 6 smd resistors in a row. If you notice the 5th one (with board vertical and pci to left and floppy to right),

you'll see continuity between pin6 and one end. You'll see continuity between the other end and ground.

I've found that with #2 pencil shading, the best I could do was about 2v (slightly less). No doubt with a higher pencil, I'd imagine it'd be possible to get more.

But I made a hybrid of copper ink and pencil and managed to bring vdimm up to 2.18v (well 2.34v also, but that was too much for a
I would have rathered 2.10v as a baseline, but seeing how the p5b only has +0.3v as a max, and I want 2.5v as a max, I guess we'll have to compromise.

I've found initial resistance to be 568, with vdimm 1.8v.

With 508, I saw 1.96
420, 2.34
and 450, 2.18.

Hope this helps.

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Is the resistor you shaded black with white writing or a brown colour? Is it 568 ohms or 568 kohms? Im gonna look for it on mine. Did you get those voltage increases with bios set to 1.8v? I have tried 2 different resistors and shading each lowered resistance to ground. I dont want to measure the voltages when running with a dmm cos its hard to be still when its in the case - does AiSuite actually report real vdimm or just what you set in bios?

aisuite does not report actual vdimm. you need to use a multimeter to measure. establish a baseline first so you know what you're dealing with.

that said, if you don't want to take that risk, either take the motherboard out (easier to work with) and have the contacts made while someone else pushes power on.

or just run with it and see if your ram scales better afterwards.

i dont rememebr the color and have to go at the moment, but i did bracket the correct resistor in my case in one of the posts.

I have worked out the vdimm pencil mod for the P5B vanilla rev 1.03G. I have posted details here:

http://www.xtremesystems.org/forums/...109099&page=23

Hope this helps :)