newbie needs help!!!

[gicahagi19]

Hello everyone!

 

I want to overclock my E6300 system beyond 500fsb, but I have trouble getting my memory to be stable at that speed (1000MHz). My CPU can still go up, but the memory diplays errors in Memtest. To isolate the issue, I've overclocked only the memory, while keeping the rest of the components (CPU included) at stock speed, and that proved to me that the memory doesn't scale up as I hoped.

 

I have tried variuos combinations of voltages and latencies, still no success. The memory I'm using is Corsair, it can do 4-4-4-12 @ 675MHz (http://www.corsair.com/corsair/products/specs/twin2x1024-5400c4.pdf)). I have found reviews around the net, and most people are recommending these memory modules, as some have succeeded running them past 1000MHz (anandtech I think).

 

I tried setting the latencies to their lowest possible in order to go higher with the FSB, but still it didn't help. I even tried voltages up to 2.45, still no success. It seemed sometimes that more voltage makes them more error-prone in Memtest, so I tried with lower voltages but they wouldn't run anymore. The only setting that I couldn't try was running with a CAS of 6, it looked like CAS 5 is as low as they would go. Wondering if CAS 6 would help...but how to make them boot then, I mean, can these modules work with CAS 6, can ddr2 generally run at CAS 6???

 

My mobo is a ASUS P5B-Deluxe, chipset Intel P965, with the latest bios. I have completely run out of ideas, I've read every bit of info I could dig up from the net, none helped. My last resort is to share the problem with other Corsair specialists and enthusiasts, hopefully someone can help me with this problem...

 

An overclocker in distress... :(:

[DerekT]

Your ram is holding you back for higher FSB's. As well, 500MHz FSB is not an easy event to obtain. Certainly with 667Mhz DRAM you are going to choke the life out of the ratio anyway.

 

Doesn't scale up as you had hoped. What were you hoping to get that 667 to do? 1000Mhz.

 

These are not AMD's. You can not dummy down the ratio like that and get stability. 2.1v is the maximum recommended voltage for these memory module and certainly driving 2.45v through them makes me wonder just what you are up to in your quest.

[gicahagi19]

I am not in danger of destroying my memory because I have good airflow inside my case, and there's a side fan constantly blowing outside air on the memory sticks. I am sure these memory sticks can do more. I have the ratio at 1:1, isn't that the best setting (lowest anyway on my mobo)?

 

I have succeeded booting at 510FSB, timings at 5-6-6-18, voltage 2.35, but it does crash not long after that. I am hoping to reach 500FSB stable, and it does boot into windows at 500FSB, however it doesn't last under Orthos blend tests, or Memtest+.

 

That's why I am here seeking advice, I hope someone can point out something I overlooked, or give me a piece of advice, maybe burning in the memory could help (however I never did that nor do I know how to do it exactly). I was also wondering if loosening the timings even more at 6-6-6-18 would help, however it doesn't post with those settings, could someone tell me why?

 

Mostly, I can outline that as soon as I go past 450FSB it starts to get unstable, few errors here and then, poping out in memtest.

 

And why should I be insane to try it? It is about being as adventurous as can be, squeezing the maximum possible out of budget components!:roll: I have read somewhere on the net that the record for xms2 5400UL is around 1110Mhz, why can't I hope to get to 1000MHz stably with my sticks? My E6300 could certainly go to 3.74GHz at 1.5v, it has showed no sign of fatigue at 3.5GHz. I have a good motherboard...so stable 500FSB maybe is not unreacheable after all..

 

Maybe all I need is for someone more experienced (hell, maybe crazier than me) to help me...

 

DerekT - don't take it as an offense, I appreciate your input. if you have any other ideas, I wholeheartedly welcome them...

 

PS - it looks as the RAM is holding me back, but I don't have the money for superior RAM at the moment, and I do expect my Corsairs to scale insanely (knowing Corsair makes the best)...

 

MANY THANKS TO EVERYBODY READING THIS THREAD AND FOR REPLYING :biggrin:

[Yoxxy]

It's not the heat that is problem, it is the current. Search Google for Electron Migration.

 

2.45v will kill those dimms over a short period of time, could be a week, could be 3 months.

[DerekT]

I am not in danger of destroying my memory because I have good airflow inside my case, and there's a side fan constantly blowing outside air on the memory sticks. I am sure these memory sticks can do more. I have the ratio at 1:1, isn't that the best setting (lowest anyway on my mobo)?

 

DerekT - don't take it as an offense, I appreciate your input. if you have any other ideas, I wholeheartedly welcome them...

 

Of course I do not take it as an offence. You have every right to do what you wish to the parts you own. Be clear though, the characteristics of highly overvolted parts will show on a warranty check regardless of how excellent the thermal dispensation of the parts.

 

If you take into account transitory and electrostatic migration levels on the 55C non-overclocked CPU and on a heavily overclocked CPU you would see what I mean. The difference is marked and is one of the reasons why so many overclockers wish to stay much lower than the Processor Stock Thermal SPec rating when raising voltages. This only works until a threshold is exceeded though.

 

There is a condition called "Threshold Voltage" which is the amount of power necessary to turn on and switch the transistors gates.

 

There is a formula for the switching power:

 

Power ~ ½ CV ² Af

 

This formula states that dissipated power is linear with the effective capacitance, activity and frequency. Power increases quadratically with the CPU's/DRAM and other parts increased core voltages.

 

Thus when you overclock you are increasing the necessary voltage by a multiple of four and the voltage effects are not linear but multiplicative, quadratic and exponential.The characteristics of Electrostatic Migration and Electrostatic Discharge are then functioning far more greatly when overclocked.

 

There is more to overclocking than heat dissipation of the parts.

[gicahagi19]

OK...you're saying that wanting to reach 1000MHz with these modules is unrealistic, so I want your opinion on my current stable overclock: is 900MHz on my Corsairs at 5-5-5-15 and 2.1v considered a good/great overclock??

 

Maybe I'll settle for now and justify the investment in better RAM later...

[DerekT]

OK...you're saying that wanting to reach 1000MHz with these modules is unrealistic, so I want your opinion on my current stable overclock: is 900MHz on my Corsairs at 5-5-5-15 and 2.1v considered a good/great overclock??

 

Maybe I'll settle for now and justify the investment in better RAM later...

 

I am saying that the voltages you are pumping through that DRAM will lessen the life of it and as you stated that you were even trying voltages of 2.45v. Now some DRAM can handle that voltage, but that DRAM is expensive and if you try to treat your 667 as though it were top end 8888C4 or 6400C3, it will serve to have your ram a short life. After a while, you will have blue screens, then you will have to lower voltages, raise timings and lower bandwidth. Then it will happen again and you will have to lower again. Finally your DRAM will not work, you will RMA and find that the overvolted characteristics have voided your warranty. By pumping 2.45v through it, you might well have already created those characteristics and voided the warranty though.

 

Any overclock that is higher than a full step on DRAM is considered good. Anything above that is icing on the cake and one has to be lucky to find early released DRAM that will allow such throughput. Usually the releases are short lived as different DRAM is found and the higher throughput DRAM is binned for higher (read more costly) released product lines. :)

 

So most PC5400 667MHz DRAM that can make 800MHz is considered good. If you can make 900Mhz with 5 - 5 - 5 - 15 at 2.1V with 667Mhz DRAM you must see that this is good.

 

You have good throughput and your machine must be snappy at those speeds.

[gicahagi19]

So most PC5400 667MHz DRAM that can make 800MHz is considered good. If you can make 900Mhz with 5 - 5 - 5 - 15 at 2.1V with 667Mhz DRAM you must see that this is good.

 

You have good throughput and your machine must be snappy at those speeds.

 

I guess you are right...anyway, thank you for taking the time to help me, just a few more things you could clear up for me: I am running 4 instances of Orthos, 2 x blend, 1 x gromacs cpu stress, 1 x Large FFTs to test the stability of my system - is this a good way to test? My CPU does get rather hot but is within safety limits, full load is around 58C. 61C is the limit for core 2 duo, right? I should have bought a Zalman, but went the cheapo way and it seems my Arctic Cooling Freezer 7 does not really cut it...

 

DerekT, owe you one!;):

[DerekT]

I guess you are right...anyway, thank you for taking the time to help me, just a few more things you could clear up for me: I am running 4 instances of Orthos, 2 x blend, 1 x gromacs cpu stress, 1 x Large FFTs to test the stability of my system - is this a good way to test? My CPU does get rather hot but is within safety limits, full load is around 58C. 61C is the limit for core 2 duo, right? I should have bought a Zalman, but went the cheapo way and it seems my Arctic Cooling Freezer 7 does not really cut it...

 

DerekT, owe you one!;):

 

I run Orthos for 4 days. During that time I use the system for everything, even gaming and multi-media. Core2's have no problem with this at high overclocks. Your way is fine as well. I run 52C full load with my BigTyphoon.

 

I personally would say that a full load of 58 C is alright as long as you turn your computer off for a few hours every 48 hours or so if you are running Folding At Home X 2 or some other program that runs your system at close to load 24/7. If you are in the habit of turning your system off or standby (S3) then you are certainly fine at that thermal even if it is at the higher end of the spectrum.

[gicahagi19]

Guys,

 

I discovered some interested things today...if I run at 900MHz 5-5-5-15 my memory gets around 4736MB in Memtest, but if I run at 800MHz 4-4-4-12 I get 4973 in Memtest. This means I would have to run my E6300 at 2800Mhz (400FSB) which allows me to turn on silent mode for my fans and even undervolt my CPU...

 

This leads to the obvious question: what do you think is more important? To have more CPU power (but get noise, heat and lower memory bandwidth)? Or to have more memory bandwidth (and get less heat, noise and CPU power)?

 

Maybe if these things were simpler to understand, an overclocker would know when to stop :o: ...however it is in human nature to want more :D:

 

Thanks again for your replies!

[DerekT]

Bandwidth is only one variable in the highly tuned and performing system. Since this is a DRAM focused website, it is the main focus but you need to marry both CPU Speed and DRAM throughput.

 

You need to find your sweet spot. Where your CPU and DRAM meet to provide the fastest results with the silence you want. Your overclock is about "You". :p

 

Use a digital stopwatch and load/run the programs that you mostly use. Not esoteric canned benchmarks but real life programs that are your mainstay.

 

Play with your settings within the parameters that we have discussed. Find your sweet spot. That's the fun of this. Some people do not seem to enjoy the overclock and I wonder why they do it.

 

There is a reason why it is called the "Art of Overclocking". It is not as simple as driving high amounts of voltage through parts in an attempt to pull every erg of force one can out of the part.

 

It is about delicately extracting every erg of power with the least amounts of voltages and this takes time. Usually when I buy a new processor, it takes a month of playing with it before I find my sweet spot. It only takes a few days to find the starting point but that when the fun really begins.

 

No, it is not simple, it is fun :)

 

Love the overclock, live the overclock, be one with the overclock.

 

:D:

[gicahagi19]

UPDATE

 

After more testing I have found that the best setting for maximum memory bandwidth is 4-4-4-12 2.05v @ 400FSB, just before the motherboard's strap change which happens starting with 401FSB (more info here).

 

Having stabilized my memory settings, I wanted to see what can be further optimized about my E6300... At 2.8GHz, an E6300 is not even close to its limits, thus no need for extreme voltage for it to run. Therefore I started thinking about undervolting it for less heat and fan noise.

 

There is no real undervolting guide on the net for Core 2 Duos, so I developed my own methodology. The fact is that for an unknown reason, the AUTO voltage setting for my Core 2 is giving it far too much voltage, as it shows on my P5B-Deluxe. The E6300 can do with far less voltage, although I can't say if that applies to other Core 2s!

 

The method consists of lowering the CPU voltage by two steps - then running 4 instances of Orthos for 5 minutes (1 large, 1 small, 1 blend, 1 gromacs). If no error is found, we can lower the voltage by another 2 steps, testing and so on. When the first error shows up, I would go up by one step in my CPU's voltage - then testing for a few hours at least. If another error shows up, one more step up in the voltage would be required, and so on...

 

For me, the first error appeared in Orthos at 1.05v, now I'm at 1.075v and I'm planning running Orthos for hours, combined with some heavy gaming. So far, after 1 hour, it looks stable.

 

I hope this can serve as a guide to those who wish to try undervolting themselves! I know I changed my priorities - thats getting the maximum performance at the lowest possible settings for noise and power consumption!

 

Good luck!:cool:

[Yoxxy]

Stock Voltage on a Conroe is 1.35. I believe you mean to say 1.05 and 1.075.

[DerekT]

Your Northbridge has an internal clock speed and latencies just like your CPU and memory. The FSB of your north bridge can be found by dividing your original CPU multiplier by your set CPU multiplier and then multiplying by your FSB.

 

You have an E6300 (266 * 7) at 400Mhz x 7 your NB FSB is:

 

• (7) x 400 = 400Mhz FSB (1600Mhz Quad Pumped Total)
  
  

 

Now let's your memory may be able to run at 4-4-4-12 at 1000Mhz, however it needs to run at 5-5-5-15 at 1200Mhz. Thus your Northbridge has a series of latencies which it must adjust in order to maintain stability at this FSB. These latencies play a far more significant role in system performance than DRAM timing latencies.

 

Intel has predefined specific latencies at specific NB FSB speeds. They are referred to as straps. There is a strap for when the NB FSB is 1066Mhz and under, 1333Mhz FSB and under, 1600Mhz FSB and under, ect. When you go from the 1066Mhz FSB strap to the 1333Mhz FSB strap, the Northbridge's internal latencies loosen to allow for greater stability.

 

ASUS has redefined the NB strap so that the 1333Mhz FSB strap does not come into effect until 401Mhz FSB (1604Mhz). There are other parameters of the straps that are not currently known.

There are 2 ways to bypass the NB strap:

1. Boot to windows in the 1066Mhz strap and then use Clockgen to increase your CPU's FSB. You can then get to a much higher FSB while maintaining the 1066Mhz strap simply because the BIOS does not adjust the Northbridge's latencies in real time.
   
   
    
   
   
2. Purchase a a X6800 or QX6700 (or even a ES chip). To the Northbridge, you are always at a default multiplier with a Extreme Edition processor. This allows you to set a much lower or higher multiplier without the NB FSB being effected.
   
   

[gicahagi19]

DerekT,

 

do you know by any chance where do I find the 1T/2T switch for my RAM in the P5B-Deluxe bios? I see people reporting that you get more out of your memory by running it at 4-4-4-12-1T instead of 2T. I have 4-4-4-12 running, however I don't see where I can select 1T. Maybe it is named differently in my MB's bios? Actually, what does 1T/2T refer to?

 

Thanks in advance!

[DerekT]

Intel sets the Command Rate at the Northbridge level, and it is not normally addressable since Intel locks the feature at the 2T rate. Some Nvidia based boards have this setting addressable and this will allow you to set the Command Rate to 1T, however this almost always will serve to create an instable system.

 

To answer your question, the Command Rate for a memory controller is set to 1 or 2T normally. At 1T, the controller can issue commands on every clock cycle, if set to 2T, the controller can issue commands only on every other bus cycle.

[gicahagi19]

Thanks for the info! :D:

[DerekT]

You're very welcome :)