My EP45-UD3P dual channel experience

[Eldan]

The last time I built a PC I was splurging on a 486 and 32 megabytes, so forgive me if something I say is Motherboards 101. I was pretty unpleasantly surprised that a new motherboard and ram rated less than the board's max would fail to post out of the box. After finding that two sticks would work in single channel but not in dual channel I was even more confused. Especially since I was not even trying to overclock anything.

After many trials it appears (memtest is still running) that I have my 4 sticks of PC-8500 DRAM running stable at their rated speed and voltage: 1066 Mhz, 5-5-5-15, 2.1V.

The thing is, I did it by disregarding the advice I got from both Gigabyte and Patriot memory. Both recommended boosting MCH core to 1.3 or 1.4 for four sticks of RAM. While I was never able get 1066 by doing that, I found some stability by lowering the multiplier and running the ram at 800.

However, it turns out that by lowering the MCH core to 1.05 I was able to set everything else exactly as specified by the components and it's running right now with no errors so far. So in the end (is this the end?) all it took was a -0.05V tweak to MCH core voltage and raising the DRAM voltage from 1.8 to the voltage specified by the ram manufacturer (can't the BIOS pick that up too?).

I know this is just one data point but maybe for this board or this ram I think the stock advice of bumping up MCH voltage should be revisited.

[Lsdmeasap]

Re: My EP45-UD3P dual channel experience

Well for 4x1GB you would normally need 1.24-1.28 MCH Voltage, so 1.3-1.4 is a bit extreme. But yes, that is normal to have to adjust MCH, most of the time this would be a increase but it does seem that some boards are actually overvolted to begin with and lowering it is what helps. I have not seen so many UD3 models with this issue, but it did show up alot in the P45-DS3R

If you run into instability I would suggest you try 1.15-1.24 and see how that goes for ya.

Ram voltage would always have to be set by the user to spec'd amount, you may not need that full 2.1V as that is just the max warrantied. But with 4 sticks at 1066 you may, but you can always try 2.0-2.05 later on if you want.

If you run into anymore issues, or have any questions please feel free to post back anytime.

[Eldan]

Re: My EP45-UD3P dual channel experience

I don't mean this in a disparaging way, but how much of this advice is based on engineering and how much is medicine-man collective pseudo-knowledge?

I followed your advice on this forum in selecting 1.3V MCH; now you say that's a bit extreme. But it turns out that I cannot find a stable 1066 setting at greater than 1.05 V, and even though I just said so, you recommend > 1.1V again. Why?

You write "some boards are overvolted." Does that mean there some large unknown positive offset from the voltage I select in the BIOS to what actually appears on the board? How stable is this offset? Doesn't Gigabyte QC measure the board voltages vs. settings in some kind of test before shipping?

[Lsdmeasap]

Re: My EP45-UD3P dual channel experience

I only suggest 1.3-1.4 for 8GB or in extreme speed situations or certain users wanting to run some specific timings. Normally for P45 boards and 2x2 or 4x1 my suggestion (Depending on overall Ram speed, FSB, and all other voltages and timings) is 1.24-1.28/1.3

You can't always just grab something suggested for someone else and expect it to always work for you in all instances without asking about if it should apply to your case or not.

I said, if you run into issues to try > 1.1 not that you need to now. And I did say, it is a known issue that some boards are already overvolted and will need a decrease.

What I mean by that is some are already set at 1.15-1.2 but show 1.1 as default. I am sure quality control is in effect, but 1000's of boards I am sure do not get fully tested that is how DOA, ect happens.

Not sure about how to answer your first comment, I am not a engineer though. I do own several Gigabyte boards, and have owned many in the past. But I am just like you, a end user, that is here to help.

So yes, I suppose this is Medicine-Man Pseudo-Knowledge. But it is coming from one with Trusted and Known hands on knowledge of the items at hand with many years of experience.

Since you have got your board working fine you can for sure leave it, I only made the above comments as suggestions if you had issues down the road.

I'm only here to offer help from one knowledgeable user/overclcoker to another

[Eldan]

Re: My EP45-UD3P dual channel experience

Please understand, I don't mean to denigrate anyone personally. I could have put it more tactfully, like "it's more of an art than a science." But I'm a scientist.

Maybe I can make my point again more clearly. I am running 8GB. The advice to increase my MCH voltage based on increased amount of ram was given confidently, both here and privately by Patriot. And yet I could not find a stable 1066 setting until I lowered MCH below the default value. And when I did that it turned out to be the only tweak that was necessary. I mention this and the response is sort of: "my recommendation can't be wrong; must be the board is 'overvolted' or something."

All I'm trying to say is: since we're relying on shamans to heal sick motherboards, maybe we can revise the recipe to add: "If increasing MCH doesn't work, try decreasing it."

[kick]

Re: My EP45-UD3P dual channel experience

Yes there are some "Do this and it will work "(this is God speaking) tips running around .
However I dont think theres is anyone sitting waiting with 20 mbrds and a huge selection of ram and cpus waiting for posts to power them up and test.
I mean my case which isnt the same as everyone elses,I have to use close to the recommended max voltages for everything,but it seems to work ok.
I found Lsds posts helpfull,and he seems to have helped others with oclocking on mem and cpu . After your post i may try undervolting mch even tho Im on 2 sticks just to see if i can break my 1015 mhz memory barrier on my 800 mhz mem.
Ive seen sites which say u may get better speeds out of cpus too by undervolting them,(not happening for me).
Im a "shaman" tossing out what I think but mainly based on this works for me.. i try not to get into specifics,if its not my components.
I remember being happy with my celeron 300 oclocked to 480..grr i couldnt get 500 btw.My pentium 1 90mhz doing 100 was another adrenalin pumper .
This is a gigabyte forum tho so Im still waiting for another poster who has very close tto the same specs I have.
I suppose it is art rather than a science.Think of it like the buggatti veyron?
They found they couldnt go over 230 mph even with 1000 bhp,kws of energy or whatever way u want to put it.
They wanted 250 mph but each mph needed 8bhp,so what did they do.Instead of extra power which they didnt have :Changed the shape of the car.Insert the 250 mph key and the rear wing drops down to cut down air resistance,the car lowers itself to compensate for the loss of downforce,the steering ratio is altered so you cant pull yourself off a straight line by much,(ie hitting 240 u drop your fries on the floor,but as you reach down for them your change of pressure on the steering wheel wont send you cartwheeling ,etc etc.
I suppose you could look at your undervolting like that,less power but more streamlining.

While Im waiting for my lotto win to come in for the Veyron and the thrill of emptying a 100l/45.45 imp Gall fuel tank in 12 minutes ill just have to try and "push the envelope" on my pc setup.Undervolting would be great btw!.

[Nickel020]

Re: My EP45-UD3P dual channel experience

There are no universal settings that will work for everyone. The reason for this is simply that no two chips are alike, every northbridge is a a little different as is every CPU. Some CPUs are good overclockers, others not, some achieve higher clocks at stock voltage, some need more voltage to achieve higher clockspeeds.
Remember that chips from the same production line sometimes end up in the $140 CPU and sometimes in the $1200 CPU, even though they've undergone the exactly same production progress.
There are so many factors involved and the relationships between the factors are quite complicated which makes it impossible to give answers that work for everyone. Some effects that may cause the same problem ahve solutions that lie in exactly opposite directions. We can only give answers that refer to the general trends of which settings help with which issues. Sometimes, as is the case with your board those general recommendations don't work, for reasons that we cannot understand.

[Lsdmeasap]

Re: My EP45-UD3P dual channel experience

Please understand, I don't mean to denigrate anyone personally. I could have put it more tactfully, like "it's more of an art than a science." But I'm a scientist.

Maybe I can make my point again more clearly. I am running 8GB. The advice to increase my MCH voltage based on increased amount of ram was given confidently, both here and privately by Patriot. And yet I could not find a stable 1066 setting until I lowered MCH below the default value. And when I did that it turned out to be the only tweak that was necessary. I mention this and the response is sort of: "my recommendation can't be wrong; must be the board is 'overvolted' or something."

All I'm trying to say is: since we're relying on shamans to heal sick motherboards, maybe we can revise the recipe to add: "If increasing MCH doesn't work, try decreasing it."

I understand, just wanted you to know that the information I said was 98% of the time correct.

You are right, it should be "updated" so to speak, but it is a rare occasion when less helps so it would often be typed (100's of times a day) for no reason. And likely cause more issues really, as most users would try less volts first and longer than need be thus expanding the issue and prolonging the solution.

I do suggest it sometimes, when I see it is a known board with this issue, or I think it could apply.