Just upgraded ram to XMS3200 now I get crashes/freezes

[dxkj]

Epox 8rda+
AMD Barton 2500+
was 256MB ddr2100 crucial now its XMS 3200 Corsair 2336


Im running this ram at 200mhz with settings 2cas 3 3 6 ras

I have two different sticks of XMS3200 that i have swapped a few times already but both yield the same result. neither can do 200mhz, and for some reason when i set them down to 166mhz I have to reset my cmos.


Any ideas?

edit:
Speed 400MHz
CAS Latency 2-3-3-6-T1
thats what it is supposed to produce and neither chip is stable.

2.8 DDR voltage
1.75 core voltage

 

[dxkj]

Ok its stable right now at 190, I still want 200 though, this cant be my motherboard because I used to have the same ram at 205 or so on here.

 

[kaZ8Teen]

umm..maybe you have to update bios? try that. most recent version is 3609

 

[paladiin]

I also have an Epox 8RDA+ (A1/C1 stepping with latest official BIOS and nForce drivers) and 2 sticks of Crucial XMS3200 512MB Ram, with my Barton 2500+ CPU.

Best I can do is 12x195FSB synched. Obviously, my RAM is rated to do more than this. This isn't an uncommon issue with the 8RDA+. While it's pretty easy to get 200FSB with the mobo, it isn't guaranteed right out of the box (unless you have Version 2.0 along with a Barton 3200+ CPU).

The usual culprit is the North Bridge. First of all, the VDD voltage is too low on the north bridge to keep it stable at high FSB settings. My VDD is below 1.6v. For 200Mhz FSB and higher, it seems the north bridge likes to be at 1.8v or higher. Secondly, the north bridge isn't actively cooled. It just has a heatsink (no fan), and to make things worse, it often isn't fitted very well due to the design of the north bridge chip (though newer boards apparently have corrected this).

Seems silly, since the FSB can potentially go so high, right? Well, even so, the board is actually rated for 166FSB CPU's. Anything higher is an overclock, and while this board is a good overclocker, it means it's not always guaranteed to perform at what we might like.

How to fix this? There are 3 possible solutions (which if done I have never heard failing yet):

1) Remove the CPU jumper that controls FSB. The jumper is normally set at 166. Moving the jumper to 100/133 (or completely removing the jumper, think it does the same thing) seems to add stability for some reason. This is the quickest and easiest solution, but doesn't guarantee a solution.

2) Add active cooling to the North Bridge. It's possible you're NB is getting too hot at higher FSB settings. Removing the heatsink and installing a HSF can increase stability at higher speeds. Again, this doesn't guarantee a solution alone.

3) Last solution involves what is known as the "VDD Mod". It involves soldering a resistor to the chip which regulates voltage to the North Bridge, which "fools" it into thinking the north bridge is not receiving enough voltage, and bumps the voltage. The higher voltage adds greater stability to FSB overclocks. Most people find something around 1.8v allows for easy overclocking to 200FSB and higher. If this is done, be sure to add active cooling to the north bridge, as the increased voltage = increased heat. This solution is by far the best for fixing this problem, but also voids the warranty and can be deadly to your motherboard if done incorrectly.

I've yet to try running my CPU at 166Mhz and putting the RAM at 200Mhz to see if I can do that, but that is kind of silly since unsynched 166/200 gives less performance than synched 166/166 from what I've read.

One more thing - I've been unsuccessful at getting my RAM to run at good timings at 195Mhz. Best I can do at that speed is 3,3,3,8 or something like that (aka Optimal settings at this speed). Anything faster (like 3,3,3,7) won't let me boot into Windows. While I'm going to play around with my VDIMM settings, I'm guessing it's the same VDD problem that is keeping me from 200Mhz in the first place.

For more info on this, check out http://www.8rdafaq.com/.

 

[paladiin]

Oh wait - you probably know all about that stuff already huh? Didn't notice who was posting this.

Surprisingly enough, I happened to get a bad stick of the Corsair XMS3200 RAM 2 weeks ago. Luckily I had 2 sticks, and one was good, so I was able to trace the problem to defective RAM. Wonder if a few bad sticks came out of a batch.

I found the problem using Prime95 Torture Test. My good stick could run just fine, the bad stick would get a Failure message about 3 seconds into the test. Aside from this, I would get freezes/lockups in 3D games (3DMark2001SE would lock up in about 20 minutes, sometimes less).

I hate to think you got 2 bad sticks, but that might be it.

 

[dxkj]

I'm at 190 2 2 2 6 right now so I can live with that if its really the motherboard. I have a floor fan blowing on the inside of the computer so i dont think that heat should be an issue .


Thanks again

 

[paladiin]

I went home and messed around a little bit with my rig. I removed the 100/133/166 jumper, set my CPU to 12x200, bumped the voltage to 1.85v, and checked it out. Instead of the mobo setting the CPU back to 1000Mhz, I booted at 2.4Ghz and went into Windows without a hitch.

However, Prime95 would crash after about 2 minutes. 3DMark2001SE also crashed, about 10 minutes in. So, ultimately unstable at this speed.

So I decided to test my RAM settings, back at the 12x195FSB like I had before and which I knew was stable. Set the RAM to 2.5,3,3,6 and set the VDIMM voltage to 2.77. Booted into Windows (never did this before - would always crash at Windows startup) with no problem. Running Prime95 while I write this.

So try that jumper trick - seems to have at least improved my RAM stability at more aggressive timings, and let me overclock higher (though unstable at 200FSB).