Why is my AXP M 2500+ OC so crappy?

[nweibley]

Ok, well... I ditched my Axp 3200+ (A mistake to buy anyways) for a newegg AXP Mobile 2500+. My stepping is IQYHA 0407 VPMW.

So, I have an Antec TruePower 550w PSU... should be fine. Asus A7N8X Delux Rev 2.0 with 1007 bios... not the best OCer... but whatever.

I'm using a Koolance PC2-601 (dont have time for a home-grown water cooled setup) and the gold CPU-200 block. Also have a GPU block on, not a big deal though. Using AS5 etc. Corsair matched 512 low latency PC3200 sticks... 2-3-2-6 timings, etc.

My problem is, my OC still sucks major. I can't hardly prime95 for 5 minutes at 2.6GHz, even at 1.825v vcore. When I do try and run that high, my temps are through the damn roof for water cooling... MBM is saying 47-48 degrees C on die! I'm running 12 x 205 for 2.465GHz ... 1.75 or 775 v (I don't remember) and 44-45 deg C! I'm FPU priming it right now, but I'm not really happy with this overclock.

I know I live in florida, I know my ambeint temps are probably way high at 77-79 degrees F, and I know my mobo isn't the best, but what can I do? I can't overvolt past 1.825 on my A7N8X, and when my proc runs full speed at those voltages anyways, the MOSFETs on the mobo are searingly hot.

Whats holding me back right now? Florida temps, mobo... whats up? I can't figure this out!

Thanks
-----Nate

 

[matttheniceguy]

That isn't that bad of an overclock, but you might be able to get more. What voltage is your chip actually getting? CPU-z and sandra and some other programs will tell you. Putting some heatsinks on those MOSFETs will help stabalize your voltage and will probably increase it a little too.

Have you done the L12 mod? I think it helps mobiles with stability at higher FSB's

As for your temps, maby try adding a second radiator to the loop. Just stick in low flow resistance heatercore before the processor or something. Adding some more fans to the underside of the existing radiator might help as well.

 

[Yuriman]

Why do you think those temps are bad? I ran my 2600 at [email protected] and it hit 54c with high end air cooling. People with lower temps usualy live up north, or can afford to turn the AC down to 50.

Btw IMO thats a good overclock. If you had gotten a pre-selected stepping from excaliberpc, you might have gotten 2550mhz, but realy that isnt that much faster. My chip is just wierd.

 

[nweibley]

I only think that because I read threads like "Ohh, on water, you'll easily hit 2.6, probably 2.7, but there are no gaurentees." type of things.

I know it's not bad I just wish it was a bit better. Doesn't feel much faster

 

[nweibley]

Yuck, my voltage is flucuating anywhere between 1.66v and 1.74 v.... although I just saw it say 2.94v ... which I'm going to hope was a mistake. Prime95ing the 2nd test now at 11.5 x 210 ... 44 deg C and my room is hot as hell! I doubt it will pass this based on past tests.

 

[Docta_Z]

buy the CPU-300 waterblock for your koolance system. Makes a big difference as you're running your cpu off a waterblock designed for a cooler running cpu.

 

[Yuriman]

Ohh im sure you couold hit 2.7ghz, but you would need a MUCH better watercooler than koolance, and about 2v, maybe more. Not something I would run all day. My 2600 on the other hand does 2.6ghz with 1.75v and air cooling.

 

[nweibley]

Ohh im sure you couold hit 2.7ghz, but you would need a MUCH better watercooler than koolance, and about 2v, maybe more. Not something I would run all day. My 2600 on the other hand does 2.6ghz with 1.75v and air cooling.

Are you saying the 2600s are easier to OC, or are you saying the 100MHz difference is extremly hard to obtain and not really worth it?

 

[fhanderson]

My 2500M is running stable at 216X12.5 2700 at 2V. It ran 53-54C underload with a SP97 and tornado(drove everyone in the house nuts). I changed to a custom built WCing(QUIET) and the temps are 43-46C underload(Prime 95). It got to 2500 at 1.75 but that last 200mhz was a grind.

 

[nweibley]

Ok, now this is weird! I turned FSB back down to 200MHz and turned multi up to 12.5... so I am at 2.5GHz ... 1.75v ...
I have been running Prime95 for the past hour, and suprisingly not a single error. Two things have changed. I cleared my BIOS, then reflashed the same one over it, because I have had reason to suspect it was a little corrupted. Other than the FSB and that, it shouldn't be priming this long. It will probably fail (still in blend mode) but I guess it is a good sign. Temps are anywhere from 42-47 degrees.

 

[nblankenburg]

just a question: are you doing anything to actively cool your Northbridge? It is stable at 200 but not much beyond that, maybe it's just getting too hot? Are you able to go with a higher multiplier and lower FSB?

I know that on mine, although I have the unlocked desktop Barton and not the mobile, that everything is stable up to 200 FSB, but any higher and it won't boot, and I think it's either my memory or my Northbridge. I ordered new memory and my own mobile 2500, so hopefully I can isolate that.

That's just my guess.

 

[nweibley]

I have a vantec stealth fan pulling cool air in, and (for now) another stealth sitting on my AGP card blowing the cool air right over my northbridge and MOSFETs. I don't like this Asus board though, I have always suspected it is a weak overclocker. It only has 4 MOSFETs for power control anyways... whereas most boards use six.... weeeaaak