ASUS P5N-E SLI Overclocking Guide - Overclock.net

TriBeCa · 10-07-07

This is meant to be a basic guide for people with no or limited OCing experience who want to overclock their ASUS P5N-E.

IF YOU HAVE SPECIFIC QUESTIONS ABOUT YOUR OC, AND/OR ARE SEEKING HELP STABILIZING OR IMPROVING YOUR OC, PLEASE ASK IN THIS THREAD, AND NOT HERE. Basically, I'm the only person keeping tabs on this thread (and that may end at some point!), whereas the linked thread has quite a few P5N-E owners who post there regularly, and that will likely continue for as long as people on Overclock.net still use this board.

I admit there's a fair accusation of this being a double post, but the originator of the stickied P5N-E thread hasn't been seen on OCN for a while, and if I post this there it's just gonna get lost in the (currently) 380+ pages of that thread. The idea here is to have something we can easily refer people to so we don't end up answering the same question, "How do I OC my P5N-E?" I've seen a lot of these lately, and it makes no sense to answer them all individually. Hence this thread.

So here we go. This guide assumes your system is a new build, but of course you can jump into it from wherever you're currently at with your rig.

Before Installation
If you're not installing an aftermarket NB cooler, at the very least you should remove the stock HS and reseat it with AS5 or some other high performance thermal interface material (TIM). The TIM ASUS uses is garbage, and your NB will get quite hot if you OC without reseating.

If there's any chance you'll be using high vcore (>1.5V) or vdimm (>2.2V), you should consider cooling your mosfets. You can see where they are here. I used a set of zalman vram sinks, and they worked great (kudos to Christiaan for that recommendation).

Running 1.568vcore, 2.1vdimm, and 1.56vNB, adding mosfter cooling appears to have dropped temps by 8-10C on the CPU, MB, and GPU. It doesn't make a ton of sense, and there are a couple other little things that could account for some of that change, but it appears that the reduced temp on the mosfets has lowered resistance on them, further reducing temps across the board. Or at least that's the best explanation I've come up with so far.

Preliminary Steps
Before powering up your system, look up the following information:
1. Stock voltage for your CPU
2. Thermal rating for your CPU
3. Stock voltage for your RAM
4. Stock timings for your RAM

1 and 2 can be found on intel's site. The easiest way is to look up your chip on newegg.com, look below the picture on the left hand side and click the tab that says "Manufacturer Info." Then click the "Manufacturer Product Page" link. 3 and 4 can be found on your RAM manufacturers site, and frequently printed directly on the memory modules themselves. See the next paragraph for more on RAM timings.

The very first thing you should do when your system POSTs for the first time is go into the BIOS and manually set your RAM timings to stock. The stock timings should be printed on the module itself, or you can find it on the manufacturers website. They typically appear in the form 4-4-4-12, which are (in order) tCL (CAS Latency), tRCD (RAS-CAS Delay), tRP (RAS Precharge), and tRAS (Row Access Spread, I think). You can find these timings in the chipset option under the advanced tab in your BIOS.

Also set the Command Rate to 2T.

Not setting RAM timings manually is the single most common cause of system instability on this board, at least amongst the issues I've helped troubleshoot on OCN. The board auto-detects loose timings for most DIMMs, which can cause instability problems even at stock.

Depending on the BIOS version your board shipped with, you should probably update your BIOS. At the time of writing, the most recent BIOS is 0703. However, many people have reported difficulty OCing with 0703. 0608 is recommended, and has unlocked CPU multipliers, which some of the earlier BIOS's don't. Note that if you have a 1333FSB CPU you'll need 0505 or later for your chip to work correctly.

If you have a thumbdrive or floppy drive, follow the MB manual instructions to use the ASUS EZFlash utility. Otherwise install windows first and use the windows utility on your MB CD.

Now, install windows, install motherboard drivers, install video card drivers, and update windows (all security updates, blah blah blah). You can really do whatever you want at this stage, and move on when you're ready to OC.

Software you'll need (google it or search elsewhere on OCN):
Orthos
Speedfan or CoreTemp
CPU-z

I'd also recommend making sure your final OC is stable by running both 3dMark06 and PCMark05 at least three times each. There are some errors that Orthos can miss, especially GFX or HDD problems.

Prepping the BIOS
The point of this stage is turn off everything you don't need in the BIOS, to minimize the possibility of conflicts. You can of course tweak this section to your liking, but I wouldn't recommend having C1E or SpeedStep on at this point. I'll also go over how to get the jumperfree config set up and ready to OC.

Advanced Tab

Jumperfree Config

AI Tuning: Set to Manual

System Clocks: NB PCIE Frequency: Leave at 100MHz

Voltage Control:
Set vcore to your CPU's stock setting minus 100mV (so, if your chip is 1.325V at stock, set it to 1.225), set memory voltage to the highest value less than your RAMs stock voltage, set NB voltage to 1.393, and set Vcore offset voltage to +100mV (this puts your vcore to stock--we use this setting, however, because there's some evidence that it reduces vdroop on the board).

FSB & Memory Config:
FSB - Memory Clock Mode: Set to Unlinked
FSB (QDR): Set to your CPU's stock FSB. This will typically be 1066 or 1333, unless you have an older chip. A note on QDR FSB: QDR stands for quadruple data rate, which is the case for all modern Intel chips. This means that the rated FSB (the value you're setting here) is four times the true FSB speed. People will frequently discuss FSB in terms of the true speed, and it's the true speed that matters for determining the CPU:RAM divider (which your board sets automatically).
MEM (DDR): Set to your RAM's stock clock speed. A note on RAM clock: DDR stands for double data rate. This means that the rated clock speed is double the true clock speed. The true clock speed is what matters for determining the CPU:RAM divider. Thus, if in this section of the BIOS you set your FSB to 1600 and your MEM to 800, you will boot up under a 1:1 CPU:RAM divider.

AI Net2: Everything should be disabled

CPU Configuration:
CPU Multiplier: Leave this alone (for now)
CPU Internal Thermal Control: Set to Auto (or enabled, or w/e it is)
Execute Disable Bit: Set to enabled
Everything else should be disabled.

Chipset:
Memory Timing Settings: As discussed above, the first four timings should be set to stock, and command rate should be 2T. All else can stay on auto.
Spread Spectrum Control: Disable everything
SLI Broadcast Aperture: Disabled
LDT Multiplier: leave this alone (for now)

PCIPnP: Doesn't matter

Onboard Devices Configuration:

IDE Function Setup: Disable everything you're not using.

NVRAID Configuration: Disable everything unless you have a RAID array.

For the rest of this, disable 1394 unless you use it, disable JMicron SATA controller, and leave the rest (or set it for what you need on your system).

The rest of the BIOS is up to you.

Once everything is tweaked to your liking, save your BIOS settings. If you have a bad OC and have to reset the CMOS you'll all this. Saving to a thumbdrive or floppy is highly recommended.

Overclocking!

Before you start OCing, you need to remember: always monitor your CORE temperatures, not CPU temps, and do not let the CORE temps exceed the thermal rating for your CPU.

Part 1: FSB OCing
This board has an FSB hole in it. The goal of this section is to find it, and to find which FSB's you can post at so you don't give up later on at a speed you can actually do a lot better than. You can skip this section, but it'll help you get a better OC.

First, go to your CPU Multiplier and set it to 6x. Then set your LDT multiplier to 1x.

Start with a large-ish jump from your CPU's stock FSB. On a 1066 chip, starting at 1400 is probably reasonable. If you have trouble with this first jump, just back off a bit.

Here we introduce the basic OCing cycle:
1. Boot into windows
2. Run 60 seconds of Orthos, on small FFTs (monitor temps!)
3. Reboot and increase FSB again.

Climb your way up in 20-25 MHz FSB increases. If you fail to get into windows because your system freezes, increase vcore by one or two steps and try again. If you hit a point where several vcore increases aren't helping (especially if you're getting a system hang during the 60 seconds of orthos), try increasing the NB voltage to 1.563. You will probably hit this point somewhere between 375-450 FSB. The 1.748 voltage is also an option, but I would only use this with good aftermarket NB cooling, and even then sparingly. It will most likely damage your chipset over time (though it won't kill anything instantly, unless your cooling situation is really awful).

If you fail to POST entirely, immediately record the last succesful FSB you had. From this point on, record every FSB you can POST at, as you're now (probably) exploring the FSB hole. You want to know which FSB's are an option for your board.

Skip the FSB you failed to post at, and go on to the next one. Just keep on climbing until you move through at least 200 MHz (preferably more) without being able to post. For example, on my board I'm unable to POST between 1601-1625 and from 1671-1699. Eventually you'll hit a wall. If you want, you can go back to your last succesful FSB and increase in 5 or 10 MHz increments.

Now you've got this list of viable FSB's, which will be really useful for getting your actual stable OC.

Part 2: Getting your max stable CPU OC
Set your CPU multi back to stock, and put LDT multi back to 5x. Also put all your voltage back to where they were before you started. Note that with your CPU multi at it's stock setting instead of 6x, you'll need more vcore to boot at most FSB's.

Start at a low FSB that you tested in Part 1, like the first one you tried. Use the basic OCing cycle I described above, again using 20-25MHz increments. As before, if you run into problems (system hang while loading windows or while running orthos, or a BSOD) increase the vcore, or NB voltage if vcore isn't helping. If you're having trouble with NB volts at 1.563 and you think the problem is NB rather than CPU related, try moving up a few MHz. Some settings are just hard on the chipset for some reason.

Once you hit your goal, or you hit the maximum vcore or core temp under load that you're comfortable with, stop.

Before you consider your system stable, you should run at least 8 hours of orthos, and pass 3 consecutive runs of 3dMark06 (and PCmark isn't a bad idea either). Orthos errors at this point will almost certainly require an increase in vcore. If you feel your vcore is tapped out, then you'll have to reduce the FSB to get a stable OC.

Stability Troubleshooting:
Some things I've encountered that can help you get an OC stable if it's most of the way there but it won't quite behave. Other than increasing vcore or NB voltage, that is.

1. Try a overclocking or underclocking your RAM to get a 1:1 divider. This can cause a previously unstable OC on your CPU to become stable.
2. Try reducing your LDT multiplier to 3x or 2x. LDT multi has very little effect on performance (it basically just drives the performance of the southbridge), but it can affect stability.
3. If a 1:1 divider doesn't help, make sure you RAM is at stock clock, timings, and voltage! See the beginning of this guide for more on that, but not having this set right can cause stability problems at stock.
4. Try (just try it) reducing NB voltage, if you increased it at an earlier FSB that you're not currently testing. The FSB hole can create FSB's that might demand lots of NB voltage, but those demands can go DOWN once you get through that part of the hole. And overvolting the FSB can cause stability problems as well.
5. If your RAM is oc'd and you've increased vdimm, try reducing it. I'm fairly certain the voltage regulators on this board are a bit finicky, and sending too much voltage to the RAM can result in undervolting other components, and instability.
6. I'd love to hear other success stories here, and I'll add them in.

Part 3: OCing your RAM
This is a generic process, not really specific to this board. You can read around OCN or ask others for help with this. I include it here to highlight the fact that you should get a stable OC on your CPU before OCing your RAM, unless you need to OC the RAM to get stable (see above).

I also recommend tightening up your RAM timings once you've settled on your RAM clock. See the guide in my sig for details on this. In addition to the 4 primary timings and the command rate, you can get substantial bandwidth boosts out of tRC. CPU-z will report what this is set at. As you OC your RAM and/or tighten the main 4 timings, this will get looser and looser. But on my Dominators at least you can get this timing quite tight, and it matters. It defaults to 30 on auto, but I'm stable with it at 7. Win!

That's all for now. Post here if you want me to add/edit anything, or if I've made any grievous errors.

Good luck OCing!

|talian $tallion · 10-07-07

Koffee · 10-07-07

I'm looking to buy this board, will use this when i get it.

Ravin · 10-07-07

Good post, and great links! There is one question that I know was posted somewhere in the 382+ page sticky but cant quite recall. You skim over it briefly and that is the FSB hole(s). Do you happen to recall where they are?

alexisd · 10-07-07

Quote:

Originally Posted by Ravin

Good post, and great links! There is one question that I know was posted somewhere in the 382+ page sticky but cant quite recall. You skim over it briefly and that is the FSB hole(s). Do you happen to recall where they are?

What you need?

Ravin · 10-07-07

Quote:

Originally Posted by alexisd

What you need?

Thanks...but nvm...I re-read and found it. And I think it's may be where I'm stuck trying to get above 3Ghz. I'll try and shoot past it and see what happens!

alexisd · 10-07-07

Quote:

Originally Posted by Ravin

Thanks...but nvm...I re-read and found it. And I think it's may be where I'm stuck trying to get above 3Ghz. I'll try and shoot past it and see what happens!

Yup just past that and you going to pass that hole.Go for it.

rkshelton21 · 10-07-07

You are the man. Great post!
And VERY good to start a new thread.

Perry · 10-08-07

Very cool. I'll be using this guide tonight possibly...that is if games don't suck me in although I'm thinking that with the HSF I have, 3.6Ghz may be as high as I want to go. I'm running at 55 degrees under full load with Orthos so I have 9 degrees to play with which makes me breathe easy considering the furnace of a CPU I have.

TriBeCa · 10-08-07

good luck!

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ASUS P5N-E SLI Overclocking Guide

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