Strange overcloack results.... e5200 Wolfdale

[ibex333]

So I tried overclocking my e5200 when I bought it, and it would freeze and BSOD my PC at anything higher than 3.1GHz. Eventually it started crashing or freezing my PC even at that speed, so I backed down to default. Weird, since people get these CPUs to 4GHz, and I have a good cooler, and a spacious case and all...

Anyway, I used this CPU at stock speed or about a year and yesterday I decided to overclock again since I got nothing to lose, planning to go for Sandybridge now, or sometime very soon.

Amazingly I am running at 3.5GHz stable, with no issues whatsoever! Maybe I can even go to 4GHz... and the temps are not even going very high. I go up to 60 degrees at the most. What gives? Maybe because the overall room temp is lower during winter? But during my originaly overclock I didnt have very high temps anyway! Only 60-67 degrees.

One very strange issue though. When I run CPU-Z it doesn't show a constant 3500MHz. It constantly fluctuates between 1600 or so and 3500. What is causing this I wonder? It is as if something is constantly trying to throttle the CPU back but every now and then it goes back up... I noticed that every time I run a game CPU-Z starts showing a more or less constant 3500. When idle, it almost NEVER shows my OC speed...

Help? Advice? Thanks.


Sorry, this has been answered MANY times over and even has it's own sticky.
http://forums.anandtech.com/showthread.php?t=153761
AT Mod
Gillbot

 

[VirtualLarry]

One very strange issue though. When I run CPU-Z it doesn't show a constant 3500MHz. It constantly fluctuates between 1600 or so and 3500. What is causing this I wonder? It is as if something is constantly trying to throttle the CPU back but every now and then it goes back up... I noticed that every time I run a game CPU-Z starts showing a more or less constant 3500. When idle, it almost NEVER shows my OC speed...

Help? Advice? Thanks.

That's SpeedStep (EIST) and C1E. Disable both of those in the BIOS if you want to lock in your speed all the time.

 

[ibex333]

I dont think I have SpeedStep in my bios.... But I'll check.

 

[Deanodarlo]

As above, that's speedstep.

You want it enabled - it saves you power and heat. Why have a 3.5Ghz chip for surfing the web - it will increase in speed only when needed. Some motherbaords alter the voltage too, to save even more power and heat.

It sounds like you are new to overclocking. Read on the web about safe voltages, mem speeds, timings and ratios, speedstep, FSB limits of your motherboard etc.

Generally, you disable C1 HALT and EIST in your bios when experimenting, then after finding a stable overclock and voltage settings try and re-enable these functions. I much prefer to find a stable overclock with speedstep, as it's a great feature of CPU's. Plus I've found with core2's, it really doesn't limit your overclock by that much if at all on a decent motherboard.

Many run with it disabled - fine too, but if it works when overclocked then there is no reason to disable it.