E8400 OCing Curiosity

[katanaso]

Hey guys,

I'm OC'ing my E8400 to 4050MHz right now on a EA-EP45-UD3P Motherboard, but it's failing Prime95 at various times.  I'm running with 8GB of Mushkin RAM as well, at 1080Mhz.  I can post the voltages of everything, as well as my hardware setup, if there's any interest or response here.

If any of you are OCing an E8400 or E8500 to 4GHz or so, could you post your settings for the Processor and the Northbridge?  I'd like to get this stable for a 24 hour benchmark of Prime95.


Thanks,

mir

[Ghosth]

I'm no OC expert, but I'd say your pushing it a step too far.

[Skuzzy]

Considering the fastest 2GB DDR2 module Mushkin makes is DDR2-1066 at 5CL, I cannot see how you are clocking it at over 1Ghz, unless you are adding an enormous amount of wait states (CAS) to it.  Even then, the signal cycle times are going to be too short for the RAM to setup before writes.

Is that the actual clock rate, or the "times 2" clock rate for the RAM?

I am running my DDR2-1200 RAM at an actual clock rate of 571Mhz, which has the same CAS as yours.

What after-market cooler are you running on the CPU?

[katanaso]

Sorry, I should write better when it's technical. 

The FSB was 450, and the RAM is running at a 6/5 ratio, so it's equivalent to 1080 (540MHz x2).  It's the DDR2-1066 5CL RAM you're talking about, Skuzzy.

For CPU Cooling, I'm using a Xigmatek HDT-S1284 Enhanced Edition.

I dropped the FSB to 445 last night, upped the VCore one more step to 3.2xxxx(I can't recall immediately while at work), and was able to run Prime95 for 8 hours on the small test.  The core temps are around 37 and 38 at idle, and got to the high 50's under 99% load.  That was monitoring using Everest.

This is my first time really trying to OC a processor like this since the batch of Celeron 300A's came out in 1998 that would go to 450, so it's fun, but at the same time frustrating when I deal with the BSoDs and reboots...

[Skuzzy]

I never up the VC of the CPU, as it shortens the life of the CPU and I run the RAM at whatever the recommended voltage is from the manufacturer.

Right now, I am at 571Mhz on the RAM and have the CPU at 3.6Ghz.  Very stable.

[katanaso]

I understand and agree about the negative aspect of it.

I was also running at 3.6Ghz without changing a thing, and the RAM was running over it's rated 533Mhz with the recommended 2.1v as well.  And it was stable, running very cool.

It's more of a fun thing, since it's my home PC.  I wouldn't dare think of playing with any of my servers like this where our organization depends on them, and I'd smack my staff if they were screwing around on any of our Windows boxes.

[FLS]

I've run an E8400 at 3.8 but it's happier (forgive the technical term) at 3.6. I run an E8500 at 4.0 with no problems. Memory at 1066.

[ink]

 Every time I try to OC, I get system crashes, the only time it does not crash if it is a very minor OC, so just does not seem worth it for me

[BaldEagl]

I had my E6750 OC'd from 2.66 to a shade over 3.5 Ghz just for fun once but I backed it back to 3.2 Ghz for daily use.

It seems to me that all the Intel CPU's OC by about 20% pretty easily.  After that it gets tougher.

[guncrasher]

Hey guys,

I'm OC'ing my E8400 to 4050MHz right now on a EA-EP45-UD3P Motherboard, but it's failing Prime95 at various times.  I'm running with 8GB of Mushkin RAM as well, at 1080Mhz.  I can post the voltages of everything, as well as my hardware setup, if there's any interest or response here.

If any of you are OCing an E8400 or E8500 to 4GHz or so, could you post your settings for the Processor and the Northbridge?  I'd like to get this stable for a 24 hour benchmark of Prime95.


Thanks,

mir

I can get mine up to 3.9 with a crappy cpu fan from bestbuy. but have it down to 3.6 since it more than run ah at full settings. would be interesting to see your voltages.


semp

[katanaso]

Thanks for the replies.  Here's what I'm working with now, which has been stable through some short Prime95 runs as well as Everest Stability Tests:

4050MHz
FSB 450
Multi 9

RAM at 540MHz

Vcore - 1.33125
CPU PLL - 1.57
CPU Termination - 1.26
CPU Reference - 0.785

DRAM Voltage 2.12
Running at 5-5-5 15 settings on the Mushkin RAM (can look at those if you'd like)

MCH Core - 1.28
MCH/DRAM Reference - 0.81
MCH Reference - 0.76
ICH I/O - 1.50
ICH Core - 1.20

Temps at idle:
  CPU -35
  Core1 - 40
  Core2 - 38

Temps at 100% load:
  CPU - 48
  Core1 - 58
  Core2 -58

Motherboard Temp stays around 46 at idle or load.

[FLS]

I'd be surprised if you can't run the memory at 800.

[katanaso]

800 x 2?  For 1600MHz?  I don't think it will do it.  I'll poke around on the net to see if people have done it with my model of RAM and relaxed timings.

Right now it's 540 x 2, so it's running at 1080MHz. 

When I had the processor running at 3825MHz (425 FSB x 9), the RAM was running stable at 565 (1130MHz), but I didn't push it past that.

[BaldEagl]

Why run the RAM faster than the CPU?  You aren't gaining anything in doing so.  If it was me I'd try lowering the RAM clock to sync it with the CPU and see if I couldn't tighten the timings to actually get a performance increase.

[FLS]

Sorry Mir, misread it.