Help Needed with X2 3800+ OC

[lmadern]

I've searched the boards for some guidance but there just doesn't seem to be

 

a) many people with the X2 3800+ yet

and/or

B) no concensus on best practices with this proc.

 

I'd like to know what vcore I should use and the upper limit on vcore for my proc.

I've seen where people have suggested not to go over 1.45v but others have said 1.55 is fine. I've even seen some go to 1.6.

 

Right now I have the rig in my sig OC'd at 245 X 10, ldt/fsb 4x and my memory at 200 1:1 at 2.5, 3,3,6 1t and it is Prime95 Stable for 10+ hours. (running 2 instances - 1 for each core) (50 deg Celcius under full load, 37 idle)

 

I'd like to go higher but don't know what is the highest recommended vcore for this chip. 245 is the highest I can get stable at 1.20 + 123% vcore.

 

A weird thing is going on through the testing process; with SuperPi core 1 would fail at a lower clock speed than core 0. But in Prime95 it's the other way around. Core 0 errors at a lower clock speed than does core 1.

 

Any help or thoughts would be appreciated.

[EdLSmith]

I have X@ 4200 and a couple of weeks ago I tried 1.55 and I could get it to load. When it would start to load, number 4 led extiguished momentarily and then system just locked up. Only thing I could do was cut power and clear CMOS then bring it up into BIOS and readjust to 1.45. Well yesterday after many days of running SuperPi, OCCT and Prime95 I gtadually worked up to 280 X 10 and it was very shaky so I tried setting Vcore to 1.55. I actually had it at 1.568 and it was solid as a rock but warmish. I ran superPi at 2870 but when I ran OCCT there was a stability problem according to OCCT. I ran dual Prime95 but 1 unit dropped off at about an hour. I thindk heat was an issue so I lowered voltage to 1.52 and order a 92mm and an 80mm Vantec tornado. I'm going to swith out my exhaust fan and also change my CPU cooler fan. Add a little noise and see if I can get temps a little lower.

I want to get stable at 2.8ghz plus. I'm fine at 2770 now, so it should not be that big a deal. Of course when I run out of air, there's water and....

 

In other words, keep trimming and playing the timings. run all the tests and keep fudging it up. Good luck.

[lmadern]

But my 3800+ isn't the same core as your 4200+ is it?

I'm not sure 1.55 vcore is too high for my chip or not.

 

Any 3800+ owners out there?

[JohnL]

I dont know if this will help you at all, but I believe that the X2 core(s) are the same as Venice/San Diegos with two smacked on one die arent they? Anyways, dont know if this is much help but I thought I would throw it out anyways. I am currently working on my OC of my 3000+ Venice and I had to iron out some settings in my ram timings, or else it wouldnt boot at all over 200FSB, now that I worked that out though, I am slowly pushing the FSB and core up. I am currently at startup VID + 104% so I dont think that you would need to give it much more than that. I may be wrong, but I just wanted to give my $.02 worth and maybe help out a little. Good luck with it though!

 

http://www.dfi-street.com/forum/showthread.php?t=23333

[Keno5net]

But my 3800+ isn't the same core as your 4200+ is it?

I'm not sure 1.55 vcore is too high for my chip or not.

 

Any 3800+ owners out there?

 

Both are Manchester cores the only difference is the maximum multiplier. These cores are 90nm and in the overclocking guide the suggestion is for 1.60 to 1.65 volt max for all 90nm cores.

 

Ken

[lmadern]

Thanks for the encouragment John. I just don't really want to OC anymore until I find out if I can/should throw more volts at the Proc. With the 1.20 +123% setting, MBM shows 1.42 volts.

 

Does anyone have an opionion (based on experience) whether or not I should push the vcore to 1.45 ~ 1.50? Stay under 1.45? etc....

[Squid1]

I dont know if this will help you at all, but I believe that the X2 core(s) are the same as Venice/San Diegos with two smacked on one die arent they?

 

No. The Intel dual-cores have two dies in the same chip but the AMD dual-cores have one die with two cores.

 

I have just been informed by the UPS slackers that my Toledo will not be here before the weekend, so I won't be able to post results until then.

[lordbane]

Maximum recommended voltage for air cooling is 1.6v - 1.65v, assuming you have a GOOD air cooler (like a XP-90).

 

I have a XP-90 on my new X2 3800+ rig and it's cool even at 1.55v @ 2750MHz (my maximum stable speed is 2800MHz or so but I have to crank the voltage to 1.6v+ to get there and I don't think the extra heat is worth it).

 

Just use the normal methodology for overclocking and slowly ramp up the FSB and then adjust voltage if it's unstable, while monitoring temperature as you do it. You'll hit the point of diminishing returns and you can decide at that point when you want to stop.

 

Many X2 3800+ CPUs don't seem to have much problem nailing 2.5GHz+ speeds, so good luck