Raising CAS Latency = Crash

[Padrino]

I built a nice system with the help of these forums about two years ago. A few days ago I upgraded my cpu from a 3200+ Venice core to an Opteron 165. To my surprise it booted up right away with what I believe were simply the exact same BIOS settings I had for my old chip, which resulted in a 400mhz overclock to 2.2ghz. I'm somewhat experienced in overclocking. I'm at the point right now where I'm trying to make some minor adjustments to coax some more out of the chip and I'm just baffled. It seems to be common knowledge that loosening up the timings on your ram will allow it to run at higher frequencies. So, I increased my CAS latency to 2.5 and eventually 3 (from 2) and it won't boot. Luckily I finally realized what CMOS Reloaded was for and managed to save a bootable setting before I got into this mess. If the only change I make is to increase the CAS latency, she wont boot. What's more is that I can decrease it to 1.5 and it seems to be pretty stable so far. Made it through 3dMark03 w/o a problem.

So it runs at 1.5 or 2, but nothing higher. I don't get it. This was supposed to be my next step to get more out of my OC! Mobo is a DFI Lan Party Ultra nforce 4. The ram is 2x512 Patriot pdc1g3200+xblk. Any help appreciated .

 

[Nagasama]

try lowering the speed of the ram instead of raising the latency. you shouldnt really have to loosen the timings of the ram to get a high cpu overclock.
if you want to super duper your ram, different story. why do you want to raise it if it will boot at 1.5 anyway? i'd try to max the cpu with ram set at 2 or 2.5

 

[veg1992]

y did u mess with the latency? just lower the ram speed.... but b4 u do all this did u MANUALLY put in the RAM Timing in the motherboard..... may help a bit..... isn't it pointless to raise it if it will boot at 1.5 anyway?

 

[Padrino]

Ok, so I suppose something just kind of clicked in my head after reading replies and thinking a bit more. It has been a while since my last overclock, so I was/am a bit rusty. My problem was that I was locking myself into a 1:1 ratio. I changed it to 9:10 and upped the FSB from 245 to 250 where it would have previously not booted, but now it does! On to 255...

You guys did help me figure this out for sure, but I like how you both avoided my question about why in the world it would crash when I raise the latency. And you ask why would I want to? It's because I know this is a step that sometimes needs to be taken during overclocking, that's why! Fortunately, I'm not at that point yet.

 

[veg1992]

stress test???

 

[Nagasama]

actually, no...it never has to be raised if you do not exceed the specs of your ram by too much. as long as you keep your ram speed at or close to its limit. you can lower the speed of your ram, thereby keeping it stable and maxing out your cpu at the same time. you shouldnt have to raise the latency when you overclock your cpu. only if you are overclocking your ram by a LARGE margin.
i didnt avoid your question, i just questioned why you would want to raise the latency when it seemed good to me.
maybe your ram just doesnt like to run at cas3. maybe it was a fluke. maybe that latency is too slow for your ram to run properly. there are lots of reason why it may have crashed.

 

[Padrino]

actually, no...it never has to be raised ...

You're right. I thought that went without saying.

Stress tested... not yet. Actually, it's about to get a pretty decent one once I log on to WOW in a sec here. But I'm done overclocking for the night, as it's getting late and I think I have reached a nice plateau atm. My ram is running at 252mhz which is pretty much exactly as far as I could push it at the 1:1 ratio. The chip is at 2.52 ghz and HTT of 280 mhz. CAS latency still at 2. 750mhz overclock so far. Tomorrow I'll see how much further I can get.

 

[Nagasama]

^^lol^^ i know i'm right.
if it goes without saying...uh, why did you say it? read your second post, second paragraph, bro.
but, in any event, nice job with the overclock.
let us know if we can be of further assistance.

 

[baron5]

ive also noticed that happens alot here where people answer ur qestions with theirs or statements agaisnt what uve done. i cant say i havent done this aswell lol