OC'ing XP2500+ and Biostar M7NCG 400

[jmciver]

Although I am definately new to overclocking, I did take the time to go through some of the archives on the subject, in particular the XP2500+. The most common method I found for locked CPUs (and I am pretty confident mine is locked based on the fact I just got it from Newegg a ew days ago) was to increase the FSB to 200 Mhz and bump CPU voltage to 1.7-1.75 (since supposedly most boards under volt a bit based on what I read).

My Equipment is as follows:

Biostar M7NCG 400 w/integrated GeForce 4MX graphics (which I am using)
XP 2500+ w/aftermarket all copper heatsink
512K Kingston "Value Ram" PC3200 DDR400 (2 x 256 dual channel sticks)

Current Settings/Results:

Vcore: 1.75 (default was 1.65)
FSB: 195 Mhz
CPU Temp: 35.5 C (idle)
Speed: 2150 Mhz

I am still experimenting since I am confident I can go higher based on what I have read here on the forums. The motherboard will pretty much let me adjust about anything I need for OC'ing including memory timing, frequency and voltage adjustment.

Since I have all of this flexibility in the bios I was looking for some advice on how to use it, in particular how adjust the memory parameters for optimum performance. I did find quite a bit of info on the CPU but not much on how to optimize the memory.

Thanks in advance for the advice.

 

[jmciver]

One other thing, When I first started to experiment, I could not get the computer to be stable above a FSB of 190. When I bumped the voltage up I was able to get to 195 and stable at idle, but I am still experimenting.

 

[Killrose]

If you want to eliminate the mem as a possible culprit, you could set timmings to: 3.0-3-3-11, and give the mem some more voltage, like 2.7v or so. But it very well could be the CPU is peaked @2150MHz

Also, using the motherboard monitor software, check the PSU voltages to make sure they are'nt stressed. Cpu core voltage fluctuations and PSU rail fluctuations could also start to cause problems at higher clocks.

 

[myocardia]

You'll want to dowload Memtest86 to test your memory at any speed you try to run it at. If it doesn't pass 30 or 45 minutes of Memtest without any errors, then either raise the vdimm (memory voltage) higher, or raise your memory timings. Also, you should download Prime95, to test your entire system for stability. Run the "Blend" torture test for quite awhile at each frequency, to make sure it's completely stable.

 

[jmciver]

OK guys, thanks for the help. So far I took both of your suggestions however the outcome was not good. Although my computer is very stable at little to no load, when I ran Prime95 (Torture Test set to Blend) for each of the scenarios you mentioned above (changing one item at a time) my computer locked up within 3-4 minutes.

I brought every thing back to stock trim just to make sure there was not anything blatantly wrong and Prime95 seemed like it would run for days (as I would expect). One other thing of note, with the exception of the last test (FSB=195, Memory Voltage = 2.7, Timings 3.0-3-3-11) the computer locked up before I could get any error messages.

As I am typing right now, I am operating at the above settings. Any other ideas? I know with this chip/memory combo I should be able to do better than stock clock speeds.

 

[jmciver]

Update.........

Well, I could not get any setting to be stable for more than 10-15 minutes under Prime95 (under the Blend Torture test). I went as low as FSB=185 before I called it quits for a while. I even ran a moderately CPU intensive game I had lying around (Sum of All Fears) with the graphics settings maxed out. Although the computer did not cash while playing the game, there still were some definate "quirks" in the game. When I returned the computer to stock settings, the game performed just fine (with max graphics turned on).

Any idea on what could be going on? I mean, the motherboard is a 400 Mhz FSB motherboard, I can change just about any parameter that you need to overclock (with the exception of CPU ratios since the CPU is locked), I have PC3200 ram which has not caused any problems (that I can visibly see anyway) and I am using the XP2500+ chip which has proven to be one of the most versitile and overclockable chips out right now (even the locked ones). So WTF??

 

[Clockless]

I think this MoBo is only meant to be running PC2700 (DDR333) RAM, maybe that is what is going wrong... I was keen on getting one of these boards myself until I discovered that

 

[myocardia]

Originally posted by: Clockless
I think this MoBo is only meant to be running PC2700 (DDR333) RAM, maybe that is what is going wrong... I was keen on getting one of these boards myself until I discovered that

Yeah, if you want to overclock, you need to buy a motherboard without onboard video. Although, they might be fine if you disable the onboard video, and put an agp card in them. For some reason, even though nVidia's video cards overclock really well, their onboard video seems to be horrible at OCing.

 

[jmciver]

Thanks for the response guys. I am skeptical about the PC2700 ram thing though. The board is a 400 FSB board so I know it is designed for the PC3200 ram. But I will buy the fact that the on board video may be causing the problem.

I ran that mem test program and when I O'clocked the CPU I would get memory errors (telling me that my memory was bad). But when I returned the BIOS back to stock settings and ran the mem test, the memory had no errors. The BIOS has a lot of different parameters that can be changed, some that I don't even recognize. I am willing to bet that if I knew how to optimize the memory timings (and other adjustable memory parameters in the BIOS) I could probably get the CPU to O'clock.

Can anybody give me some more ideas on how to optimize the memory (timings, voltage, etc.), especially someone with experience with Biostar motherboards since I am sure they are very similar when it comes to BIOS settings?

 

[Killrose]

If you are using the on-board video, forget overclocking your FSB much past 166MHz reliably. Acording to many reports i've read it was'nt designed to, and will cause you greif. That is what Clockless was refering to by his PC2700 statment I beleive. You can disable the video and get an add on-card and then try whatever you like FSB wise. The AGP frequency control in bios is not for the on-board video, but an add-on card only.


Also, the board might not like your ram in dual channel mode. Try it with one stick at a time just to be sure.

 

[Clockless]

From Hexus.net

Hope this helps...

The nForce2-powered M7NCG 400 is a strange beast. On the one hand it supports the 200FSB Barton straight out of the box. On the other, though, it's only rated to support dual-channel DDR333 memory. We feel that takes away most of the performance advantages of running high FSB speeds on an AMD K7 architecture. The cumulative effects of high latencies incurred by clock buffering and the lower bandwidth delivered by DC DDR333 almost negate the need for an XP3200+. One might as well place a Barton XP3000+ in the socket. That's especially true with the GPU-bound onboard graphics. With the onboard graphics used, it refused to run with DC DDR400 memory, irrespective of settings.

So yeah, like the others say, try running your memory in single channel mode and get an AGP card...