A Beginners Guide to Intel Overclocking. Features and Problems Explained.

[Kunaak]

This post is for New Owners of Intel Conroes, Meroms, Pentium D's, and Allendales, to explain some of the basics of Intel hardware, and Overclocking with Intel hardware.

with the huge influx of new people switching from either older Intel set ups, or just plain old moving from the A64 to the Conroe... we have a great deal of people that just have no idea what some features are about the Conroe and Intel based motherboards... and make the same posts over and over, every other day.
I want to try and help explain some of the things about Intel CPU's and the various concerns that people seem to come up with, when they dont know things, like what C1E is... or EIST.

some of the most common Questions I see.

"my board is setting my ram to 1:1 and I can't figure out how to set my ram to 1 GHz, cause I have no dividers"

all intel boards, should have atleast 3 dividers these days.
if your coming from the A64, your probably expecting the bios to look like a A64 bios. it won't.
Dividers on Intel boards aren't always obvious to spot.
some boards will clearly tell you "1:1 or 4:5" and such, but most, dont.
from Asus that uses Mem Speeds as the dividers, to gigabyte that uses memory multipliers, you need to sometimes experiment alittle to see where your dividers are, and set them manually.
most boards use the Memory speed for the divider, like setting 400 mhz, is usually 4:3, and setting 533 is 1:1, and 667 is 2:3 and finally 800 mhz is 1:2.

no board is the same. but usually the dividers are determined by the memory speed selected in bios. so start there.

Note.

Not all boards have the same amount of dividers available.
most boards have no option to go below 1:1 anymore either...

and once you start expimenting, you may find your board OC's alot better with 4:5 then 1:1 and so on... sometimes a board just OCs better with a specific memory divider, so if your not having great luck with 1 divider, try another. the difference can be drastic in some cases.

"I set 1.55 volts in bios, and I only get 1.48 volts in windows... is my board messed up?"

no, theres absolutly nothing wrong with your board, CPU, PSU or ram or anything else...

theres a unfortunate feature that every intel based board since the 875 boards were introduced, thats specific to intel chipsets.

its called "Voltage Droop".

All Intel Based boards have this... from the old canterwood 875, to the top of the line Asus 975 boards of today. doesn't matter what board you get... it's got a voltage droop, and its a normal thing.
theres no defect, no setting in bios you overlooked, no problems with your PSU, your CPU's not defective... it's just a thing that you have to live with, with any Intel based motherboard.

theres only 1 fix for this, it's called a "Droop Mod", and requires soldering a Variable Resistor, to some part of the board, and adjusting the VR, till you get the most stable voltage you can from the board.
finding the VDroop mod for any specific board should be done in the Xtreme Mods area, under Voltage mods for motherboards.
look or post there, if looking for a VDroop mod for a specific board.

however, if your looking for a Vdroop mod, for a unpopular board, dont be suprised if no ones botherd to find it.

"I set my voltage to 1.5 volts and OH MY GOD, CPUZ SAYS I ONLY GET 1.188 VOLTS, WHATS WRONG???"

first off, don't do THIS.

for whatever reason, it gets on peoples nerves when they open a post, and are doing all caps for thier letters, and posting like they are freaking out.
even if they know, alot of people will avoid the topic for that very reason.

now, again... theres nothing wrong here.

this happens for 2-3 reasons.
first, CPUZ isn't the swiss army knife of hardware monitoring. it does good, but occassionally can be wrong on the voltage.

the main reason why your voltages are way lower then you expected them to be, are 1 of 3 reasons.

EIST. that stands for Enhanced Intel SpeedStep Technology.
EIST is a feature, that adjusts your Multiplier, depending on the level of activity of the CPU.
if all your CPU is doing is browsing the internet or typing, then it will default to the lowest available multiplier, since its basically doing nothing.

this is to do many things, save on CPU power, save on actual power used, and to save on heat put out by the CPU.
theres no reason to have a CPU at full speed... if your only doing little mundane things like listening to a MP3, or browsing the net...

theres also... C1E.

C1E is a feature, then when it first came out, drove me absolutly nuts, cause no where was it explained what the feature was or even what CPU had it, for awhile after it started being used in processors.
so I'd be overclocking, run super PI, and get some great run... then C1E would kick in, and my voltage would drop from 1.5 volts, to 1.2 and my OC would stay the same... and this would always lead to instant CPU freezes.
this one single feature drove me so nuts trying to figure out what was going on, when about a year ago it started being used, and my Abit AS8 had no option to disable it, and I had no idea what it was...
I got to the point where I almost took the board outside, and smashed it from being screaming mad.
had I done that, I would have killed a perfectly fine board... cause this is a CPU feature.
a realllyyyyyyyyyy annoying CPU feature.

what C1E does, is lower the Voltage of the Processor, when at Idle, to save on heat output.
remember, a CPU is meant to only be run at stock.
Intel designs these CPU's to be stable at thier stock speed, with C1E active.

however, C1E for a overclocker, can leave you going nuts if you dot know what it is.
especially if you have a older LGA processor, that doesnt have EIST on it, but does have C1E.

C1E. if used with EIST, is actually a handy feature to have, if you want to keep your CPU temps low while at idle.
but if you choose to disable EIST, I strongly suggest you disable C1E at the same time, otherwise, this feature may drive you bonkers too, just like it did with me.

and then theres TM1/TM2.

I know what these are, Thermal Monitors.
however, I am still confused as to how these are different from C1E and EIST.

but, in my Gigabyte board here, in the bios, the description it gives is... TM1 lowers the CPU Voltage and MHz, when the CPU is at Idle.

to me, that just sounds like EIST and C1E... so I dont know how thats any different. but either of these 3 features, can and will alter your voltage readings in windows.

which is why, when you set say 1.5 volts in bios, you only see 1.2 volts, when you actually get into windows, cause EIST or C1E are active... or TM1/2.

disabling these, in bios, should obviously force the CPU to run at whatever voltage you select... assuming you keep in mind, you still have a voltage droop to deal with

"My CPU is a X6800 and I should have the 9 multiplier, but why is my CPU running at 6 x 266.... I am gonna RMA it, cause it must be defective".

I've only seen this kinda post a few times, but I have seen it enough to put it in here.

this is EIST active.

when the CPU is doing nothing, it will lower the CPU multiplier, to the lowest available multiplier. in the case of Conroes and Allendales, the lowest available multiplier at the moment is 6 x.

when your CPU goes into a heavy work load, like playing a game, running a benchmark or anything else, EIST will set the multiplier to the stock default multiplier, not the lowest available one.

once that benchmark is done, or you quite the game or whatever, EIST will kick in, and lower the multiplier back to the lowest available one.

again, this is normal.
theres nothing wrong with the processor, and no reason to think it's damaged.

this is just a general guide to help people understand what some of the features of Intel Processors are, and how to known what they do, so they can spot the problems, and not be worried when they find out this is perfectly normal.

if theres a general question you see, that the newer Intel OC'ers need answerd, then PM me, and I will add it.
I am closing this topic to make this post straight to the point, and not flooded with 20 pages of random information.

Update:

heres a Question I just got.

Very helpful post - many thanks. I'm in the switched from A64 category and I'm stiil a little confused with the Intel world. One quick question maybe should be added to the post, whats the "strap" / "memory Strap" people talk about?

Strap basically, is the Latency of the Motherboard, when different default CPU FSB's are used.
think of ram, and cas. well, motherboards have kinda the same thing.

a strap like the 1066 FSB, offers nice overclocking potential.
but a CPU with a 800 FSB, may hit a wall real fast on that same board, cause the latency of the chipset with the 1066 FSB, is more forgiving then the latency at 800 is.

one board offers a 1333 strap right now, but the latency of the motherboard, with that strap, sooooo kill the performance, that its not even worth taking a second look at.

some boards, offer you the option of forcing a CPU strap.
like DFI's 975X if you put a Pentium D in it... has a 1066 strap from the start that you can force the CPU to run at, even though your CPU is a 800 strap CPU.
that means it's timings are more agressive then a 1066 FSB CPU has.
so your OC will be most likely lower with the 800 strap if you dont change it.

most boards change the strap with the memory divider, which is why it can be alot harder to OC with one divider then another, cause the motherboards latency is controlled by the divider you use.

if you want to understand it in more detail, Tony from OCZ wrote a great article on it Here

Update on TM1 and TM2.

this person had a much better understanding of these then I ever have.
till I read this, I really didn't have much need to learn about these.

What I wanted to comment on was concerning the definition of TM1 and TM2. These are thermal monitors designed to reduce the heat in a processor that is essentially in thermal run away.

TM1 is a stop clock mechanism that stops the clock to the processor for a period of time. Then the clock is restarted for a while and the process is repeated.

TM2 is similar in that it works on the processor clock by stealling cycles. So the processor will get a few clocks then a few clocks will get stolen (no clocks to the process) and the cycle resumes.

Believe it or not, TM2 was devised because people who had processors in thermal run away were getting stuttering mouse movement with TM1 because the clock was run for a period and then stopped for a period. To me it seems that finding out why my processor was overheating would be a bit more important than why was my mouse stuttering.

To say that TM1 and TM2 is like EIST is really a mistake. They have totally different purposes and implementations.

And finally, the mode selected (either TM1 or TM2) won't kick in until 85C for most processors and 100C for some mobil processors. This is very hot, I expect you'd have guessed.