Max FSB of 865PE Neo2 LS w/ 5:4 Divider

OK, I was playing around with memory dividers the otherday becasue I wanted to see how much headroom my p4 had. Normally i run 1:1 which limits my fsb to 250 and my cpu to 3.0 due to my memory not being able to go over 250 (even with more volts it doesn't seem to do anything)

Anyway I switched on the 5:4 divider so that I know it wouldn't be my memory holding me back. I managed to run windows at 3.3ghz and it seemed stable, I didn't test with a full load, but I had about 20% load for 30 or 40mins and it didn't crash.

As I went up to 3.48ghz it started rebooting after in windows. I pushed my voltage up to 1.6 in the BIOS (even though cPU-Z says it was running in the 1.5's fluctuating a bit)

My CPU temps weren't showing any major jump only around 42C even at this clock.

Do you think I could be FSB limited, or is my CPU crapping out?

Most 2.4C's wont go above 300 FSB without extreme cooling and lots of voltage, mine takes a lot of voltage to go above 285FSB, so I run mine at 285FSB all the time.

If you can make it to 3.48 gigs on 1.6V, that's a pretty good overclock..... I'm at 3.42 gigs at 1.55V, so we're pretty close.Try lowering your speed to around 280 or 285FSB and see how low you can take the voltage and still be stable.

Don't forget to run Prime95 while you're doing that to make sure your overclock is stable and isn't corrupting your hard drive.

Hope this helps

-Meatball

mtb856 said:

Most 2.4C's wont go above 300 FSB without extreme cooling and lots of voltage, mine takes a lot of voltage to go above 285FSB, so I run mine at 285FSB all the time.

If you can make it to 3.48 gigs on 1.6V, that's a pretty good overclock..... I'm at 3.42 gigs at 1.55V, so we're pretty close.Try lowering your speed to around 280 or 285FSB and see how low you can take the voltage and still be stable.

Don't forget to run Prime95 while you're doing that to make sure your overclock is stable and isn't corrupting your hard drive.

Hope this helps

-Meatball

Click to expand...

Yeah Well it "runs" at 3.48 but not stable at all...

Do you think I need extra NB Cooling or Extra CPU cooling (both are at stock right now, cept I removed the thermal pads and put AS5 on them both) (well I also cleaned them just recently too, My previous case was a freaking Insect KILLER, I had LED fans everywhere and they were attracted to the light and most got sucked in the side fan over the GPU and got chopped up, I even found one decapitated moth wedged in my NB heatsink!)

Do you see any voltage fluctuation? (this might be a natural thing for the p4's when not at load)

Edit: Didn't look at your sig, so I took one question out.

I would recommend better cpu cooling at the very least.... I can't fit active NB cooling and have a Thermalright HS on my processor at the same time, so I went with the cpu cooling. I'd recommend any of the Thermalright HS's, they work incredibly well.... the XP-90 or the SI-97 both work with the stock Intel retention bracket, the SP-94 and the SLK's require you to remover the bracket as they bolt onto the motherboard.

My voltage drops from about 1.58V in BIOS to 1.55V in Windows, to 1.52V under load. The drop under load is normal..... and it will fluctuate between 1.545 and 1.56V during idle if that's what you were wondering about.

MTB , J-MAG , I am not sure what the FSB limit is with this board but I do remember reading over at the MSI boards that the northbridge starts to struggle at around 260 FSB especially when running memory higher than PC3200

I have the active Northbridge cooler ( with the stupid lights) on mine and it does not seem to make a difference . I asked several people and they stated that the temp difference was only a few degrees

As far as the CPU cooler I have the SP 94 and it is a great unit but I did have to cut two fins off of the northbridge HS so the " Heat Pipes" would clear. Taking the board out was also a pain but it does mount easly after that.

J-Mag have you raised the memory voltage to 2.7 or 2.8 ( which ever is the lowest that gives you a stable system) yet?
If not give it a shot as this seems to be the " silver Bullit" with MSI boards

Good Luck and let us know how you make out

Dave

as far as the CPU cooler I have the SP 94 and it is a great unit but I did have to cut two fins off of the northbridge HS so the " Heat Pipes" would clear. Taking the board out was also a pain but it does mount easly after that.

Click to expand...

Yeah, I had to do the same thing with my SLK-948 to get it to fit, it didn't take very long though, just a few quick swipes with the hack saw

As for the FSB, I haven't had any problems with mine above 260FSB, I had heard that was a general problem with the 865PE chipset, but I've been at a 285FSB for several months with PC3700 and never had any problems.

Is that a problem with processors higher than the 2.4C? I know that I've heard about problems with the 3.0C's and processors like getting over 260FSB...... the newest batch of 2.4C's doesn't seem to be doing as well b/c I've talked to 5 people so far with SL6WF's and they're all stuck at around 3 gigs.

mtb856 said:

I would recommend better cpu cooling at the very least.... I can't fit active NB cooling and have a Thermalright HS on my processor at the same time, so I went with the cpu cooling. I'd recommend any of the Thermalright HS's, they work incredibly well.... the XP-90 or the SI-97 both work with the stock Intel retention bracket, the SP-94 and the SLK's require you to remover the bracket as they bolt onto the motherboard.

My voltage drops from about 1.58V in BIOS to 1.55V in Windows, to 1.52V under load. The drop under load is normal..... and it will fluctuate between 1.545 and 1.56V during idle if that's what you were wondering about.

Click to expand...

Yeah, so I bought an XP-120 the other week because my MB was on the compatability list, but what I didn't realize, that it also matter what CASE you have it in. In my case, the 120 comes up to the seperator panel that is between the main compartment and the PSU compartment. BOOOOOO!

ANy MB that has the socket deeper on the MB and not on the edge, would work fine... SO i guess I will keep it because I plan on going to another MB eventually, maybe I should try an XP-90 until then...

Dcasole said:

MTB , J-MAG , I am not sure what the FSB limit is with this board but I do remember reading over at the MSI boards that the northbridge starts to struggle at around 260 FSB especially when running memory higher than PC3200

I have the active Northbridge cooler ( with the stupid lights) on mine and it does not seem to make a difference . I asked several people and they stated that the temp difference was only a few degrees

As far as the CPU cooler I have the SP 94 and it is a great unit but I did have to cut two fins off of the northbridge HS so the " Heat Pipes" would clear. Taking the board out was also a pain but it does mount easly after that.

J-Mag have you raised the memory voltage to 2.7 or 2.8 ( which ever is the lowest that gives you a stable system) yet?
If not give it a shot as this seems to be the " silver Bullit" with MSI boards

Good Luck and let us know how you make out

Dave

Click to expand...

As for the Active NB cooler, I have the Disco Machine they put on the board too. My side panel has been off my case for a while, because I have been dinkin around... Anyway sometimes when I go to sleep and turn off all the lights, it feel like i could have a RAVE in my room... HEH

Also, I purchased a NB-1C along withte XP-120 noted above, but I couldn't figure it out when I tried ot install it last weekend... I got some directions though yesterday, So i will try it again to see if it help stabalize my higher FSB rates...

Also, why are you saying that it struggles with greater than 260FSB with higher than PC3200 mem? Does this mean if I run pc3200 mem with a 260+ FSB it will be more stable than running the same speed FSB with PC4000 stuff?

Also, I have been running my memory at 2.8 pretty much since I got the board. I tried it at 3.1v a couple times, but that didn't seem to help my memory speed at all ( I think my mem isn't really voltage dependant like some others) Although I haven't tried that high voltage on the mem to see if it stabalizes my high FSB clock...

I did notice however, that when I upped my AGP to 1.6v it seemed to help me run a 3.3ghz more stable...

Also, why are you saying that it struggles with greater than 260FSB with higher than PC3200 mem? Does this mean if I run pc3200 mem with a 260+ FSB it will be more stable than running the same speed FSB with PC4000 stuff?

Click to expand...

I have to go back thru the archives but I remeber reading over at the MSI boards that some people were hitting a brick wall at some point over 260FSB and it had something to do with stressing the NorthBridge

Does this mean if I run pc3200 mem with a 260+ FSB it will be more stable than running the same speed FSB with PC4000 stuff?

Click to expand...

No that is not what I mean. It is just you " lucky" guys who have this great memory can achieve insane FSB speeds

Having the PC4000 is great as when you are running at 1:1 you have plenty of headroom before the memory becomes an issue

Us poor souls with PC3200 have to use the 5:4 divider in order to not push our memory out of spec.

Also, I have been running my memory at 2.8 pretty much since I got the board. I tried it at 3.1v a couple times, but that didn't seem to help my memory speed at all ( I think my mem isn't really voltage dependant like some others) Although I haven't tried that high voltage on the mem to see if it stabalizes my high FSB clock...

Click to expand...

I would not push your memory voltage any higher than 2.8v

Dave

ok here is a post were a guy states that he hit a brick wall at 260 ( I knew I was not going crazy)

It seems like there is a problem with the northbridge and the chips that they use in the memory ( they just don't play nice )

http://www.ocforums.com/showthread.php?t=339048

This sounds like the i865/875 Winbond CH5 issue, where RAM runs excellently at 1:1 ratio, yet anywhere from 240-260MHz FSB the system just wont post despite the memory divider or timings used.

I had the same issue with my 2.4C, at around 260MHz FSB and above the system simply stopped posting, even with the 3:2 ratio and slack timings (even though my RAM did 220MHz 1:1 using 2-3-2-5 timings).

At the time I was stumped, until I tried the Winbond BH5 sticks I had, and all of a sudden the brick wall I had hit was gone, and I was crusing at 3.6GHz (from just under 3.2GHz before).

Click to expand...

Dave

Dcasole said:

ok here is a post were a guy states that he hit a brick wall at 260 ( I knew I was not going crazy)

It seems like there is a problem with the northbridge and the chips that they use in the memory ( they just don't play nice )

http://www.ocforums.com/showthread.php?t=339048


Dave

Click to expand...

That thread seemed to be an issue of this guy trying to run his CH-5 chips at tigt timings.

I am more curious if my North Bridge or the North Bridge Interconnects (which is essential the reason why I put this in mthe motherboard section) on this specific 865pe Neo2 LS has a limit. Cause I know the boards like the p4c800-E
can run stable at real high FSB... And the abit board too... I can't remember was it the IS-7?

Or are you saying, that my memory might be destablized whilst running in a divider? I gues sI could get some pc4400 or pc4800 just to check this out... It would be better to run my ram at 1:1 anyway...

Which brings me to another question, would it be better to run my machine at 3.0ghz 1:1 or 3.3ghz 5:4 because I know the 3.0 1:1 is rock stable and the 3.3 5:4 "seems" stable (i haven't tested it too much)

Well I also have a feeling my PSU might be a culprit... I will have a PC Power and Cooling 510w in the next few days, so when I get it back I am gunna do a tad more testing...

I'd do some Sandra memory and cpu benches at each of the speeds and compare them.... I would think that if you're running 5:4, you might be able to raise the vdimm and lower your ram timings a bit to improve the performance, in which case running 3.3gigs would probably be better.

If it's not stable though, I'd go for 3 gigs or somewhere in between.