Making an X2 overclock stable?

Smartazz

Diamond Member
Dec 29, 2005
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I used to be able to push this chip more than 2.7GHZ on 1.45 volts. Then I moved it down to 2.4GHZ on stock volts for a month, not it'll crash if I try to do that. Am I missing something necessary to over clocking this chip? I have an M2N-E and a Scythe Mine for cooling, usually my temps max out at 51C at 2.7GHZ when I use pc probe, any help would be appreciated thanks.
edit: I tried using a divider, upped the voltage and I changed the HT frequency, still with no luck. It's an X2 3800+ Windsor btw.
 

Insidious

Diamond Member
Oct 25, 2001
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To paraphrase posts of the past and echo my own experience:

"ISOLATE AND OPTOMIZE"

Lower your RAM divider way down to isolate RAM
Lower your HT multiplier to 2X to isolate HT bus

Now, start at stock, raise your cpu volts to 1.35 (I do not agree with the above 1.35V limitation.... degrees kill CPUs... not volts (But I won't go above 1.45 on air for my pc)
Run prime95 and see how your CPU temp is doing... keep bumping your CPU volts (IN SMALL STEPS) until your MAX CPU temp is ~8 degrees below what you will allow on your PC

now raise system bus (Keep the CPU multiplier at 10X) in 50MHz increments, re-checking prime95 generated CPU max temp.

repeat until you know how high you can set your system bus without loosing system stability... this is your Max. CPU speed (write it down)

now, set your multiplier down to 8X. (to isolate the CPU) raise (don't forget to put your RAM divider back to 200 for this part) your system bus up in ~50MHz increments and boot to memtest86+. Let it run a full set of tests.

Repeat until you see ANY memory errors. (If in doubt, let it run longer). This is your max RAM speed (write it down too)

now, you want to set your system bus to that speed that takes your CPU to it's max at 10X. calculate the HT multiplier that keeps you BELOW 1000 and set it
finally, set your RAM divider that gets you up to (but not above) the max speed you recorded.

This 'quick-n-dirty' method will get you to an OC fast. It won't be the absolute max you could go with further tweaking, but you will be close.

for a quick first check, I like to boot to memtest86+ and let it run one set of tests. (it doesn't heat your CPU much and will catch any gross instabilities in a single pass.

next, I like to test my system stability with these new settings using prime95 because it is easy to monitor CPU temp and re-assure yourself that you will not be overheating it. I also like to see my MAX CPU temp 4 or 5 degrees below what I will acutally be willing to tolerate to account for room temp changes, dirt buildup, etc....

If all is still good, I lilke to go back to memtest86+ and let it run for a few hours as my last check.

Lots of MUCH more thorough methods, and I like them... use them.... endorse them. This is just the path I take to get to a good place fast.... I can try for that extra 10MHz later :)

-Sid

PS: don't worry if your HT bus is well below 1000. It makes very little difference unless you are on a multi-socketed motherboard. Also remember that (in general) with X2s, you will get more overall performance gains by getting your CPU speed up than you will with RAM speed increases
 

Smartazz

Diamond Member
Dec 29, 2005
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I did isolate and optimize. HT frequency was more than 280, RAM was 840, CPU I need to check, but that hit the wall at around 2.8GHZ last time I checked.
edit: This was a long time ago, now I can't hit anything near those speeds.
 

potato28

Diamond Member
Jun 27, 2005
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Insidious: I just assumed that OP was on air, so 1.35v is a pretty safe bet... but other than that QFT all the way! :thumbsup:
 

Insidious

Diamond Member
Oct 25, 2001
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I think your recolection may be misteken.

On air, I can't imagine a stable 2.8MHz OC on a 3800+. That would be a really nice OC for an Opty 170! (but then, I am not a guru of the OC)

Anyway, you can't wish an OC higher. They go where they go. You've aged components on your MoBo, CPU. RAM, PSU, etc..... since then.

I don't have any magic bullet for you.

-Sid
 

Insidious

Diamond Member
Oct 25, 2001
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I've had 3 3800+ X2s, used 3 different motherboards and NEVER managed to get a truly stable OC above 2.6MHz. So you see my skills are limited.

Sorry I can't help better

-Sid

(for reference, I've got all 3 of my X2s running at 2.5GHz now and am actually pretty proud of it. I do Folding@Home so I am basically always running balls to the wall. I have to be totally stable and my OCs reflect that in their conservativatism)

PS: I think the HT and RAM speeds you posted are reversed (or else you have some KILLER RAM! :shocked: )
 

Smartazz

Diamond Member
Dec 29, 2005
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lol, no I meant ddr2 speed 840, so really 420MHZ.
edit: my highest oc stable was 2745MHZ.
 

Insidious

Diamond Member
Oct 25, 2001
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oops!

I was thinking S939 the whole time I was posting. I don't know what changes for AM2

I may have just told you a pack of lies :eek:

hopefully someone with experience with AM2 will pop in.

-Sid
 
Jan 22, 2007
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Mine won't go over 2.5GHz under 1.4v... I think it's due to my board not good for OC (M2N-E), the max vdimm is 1.95v so you can't OC much...

That said, I use my X2 3800 @ 2400MHz now with ridiculous voltage (1.35v).
 

stevty2889

Diamond Member
Dec 13, 2003
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Originally posted by: potato28
Lower the volts. Any higher than 1.35v is unsafe for dual core processers.

Thats a rather generic statement. My X2 has been running on 1.425v for well over a year now at 2.6ghz and never breaks 50c on the stock heatsink..
 

Zebo

Elite Member
Jul 29, 2001
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I just built two 65W AM2 3800's + M2N-E's both went past 2800mhz.. Make sure HT is set to like 3 instead of 5... set mem to 400 not 667 or 800 then try raising vcore to about 1.45 and start cranking.
 

Zebo

Elite Member
Jul 29, 2001
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Originally posted by: stevty2889
Originally posted by: potato28
Lower the volts. Any higher than 1.35v is unsafe for dual core processers.

Thats a rather generic statement. My X2 has been running on 1.425v for well over a year now at 2.6ghz and never breaks 50c on the stock heatsink..

Hey stevty:) I don't know where these guys come from but 1.55V just as long. I was being conservative @1.45
 

Smartazz

Diamond Member
Dec 29, 2005
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The M2N-E does have overclocking potential apparently. Inspire got an X2 3800+ to 2.75GHZ stable at 1.5 volts on the same setup I have. An M2N-E with a Scythe Mine, he said his temps never went above 55C fully loaded. I forgot that tip that somebody recommended to me. I'll try it with the RAM with the slowest divider, HTT set to 3X, If I could get a stable 2.7GHZ chip, then forget about the Core 2 I have planned for this summer. Thanks for the info.
 

Boyo

Golden Member
Feb 23, 2006
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If you can get 2.7 then more power to you. I can't get past 2.68 on my X2 4400+ 939.....
 

Smartazz

Diamond Member
Dec 29, 2005
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Originally posted by: Zebo
I just built two 65W AM2 3800's + M2N-E's both went past 2800mhz.. Make sure HT is set to like 3 instead of 5... set mem to 400 not 667 or 800 then try raising vcore to about 1.45 and start cranking.

I just started doing what you just said. I'm at 2.6GHZ rock solid. Maybe there was a lack of voltage before? I think 2.6GHZ is just fine for now.
 
Dec 8, 2004
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Possibly you had a setting that was off somehow. Glad to see that you are back in the ballpark. 2600mhz is a good speed overall that shouldn't need tons of voltage. As some have said your memory controller won't like high voltages for a long period and could start to fail.

Good luck!
 

Smartazz

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Dec 29, 2005
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Originally posted by: AndyT
Possibly you had a setting that was off somehow. Glad to see that you are back in the ballpark. 2600mhz is a good speed overall that shouldn't need tons of voltage. As some have said your memory controller won't like high voltages for a long period and could start to fail.

Good luck!

lol, I was doing 1.45 volts at 2.6GHZ, is that too high. My temps really never exceeded 52C though.
 

Zebo

Elite Member
Jul 29, 2001
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Originally posted by: AndyT
Possibly you had a setting that was off somehow. Glad to see that you are back in the ballpark. 2600mhz is a good speed overall that shouldn't need tons of voltage. As some have said your memory controller won't like high voltages for a long period and could start to fail.

Good luck!

That off setting idea could be true. I think his HT multiplier was too high, common mistake. Thats like 90% of the mistakes in this board since it's located in an unusual place..hard to find couple menus down and not with normal OC options.

Smartazz try and lower volts to like 1.4 keeping same speed. I personally don't believe anything under 1.6 hurts but Andy reads results more than I do so I have more confidence in his opinion erring on the side of safety.