Overclocking 2500+, Need Suggestions

[Arcuivie]

I plan to overclock my AMD Athlon XP "Barton" 2500+ to the settings of the 3200+ in a few days, as soon as my new heatsink and fan comes in. I'm getting the SLK-800 with an 80mm 84cfm Tornado fan, and I will be using my Arctic Silver 3 on it. Will this be enough to keep the temperature low? And what do I need to change in the BIOS to accomplish this? Anything else I need to know?

The motherboard I'm using is the Asus A7N8X Deluxe, and I have 2 39CFM case fan's running.

[jmichna]

Your HS, with that fan, has a cooling effectiveness of about 0.24 °C/W. That means, for example, that if you OC your CPU to the point where it puts out 100 Watts (assuming at 100% cpu output), then you can expect the HS/fan to limit the CPU's heat rise to about 24°C over your ambient case temperature.

You can get a decent estimate of how much power (Watts) your CPU will put out under a given set of conditions using this formula:
Watts (OC'ed)=Max Stock Watts X (OC'ed speed mHz/stock speed mHz) X (OC'ed voltage/stock voltage)^2

(This formula was derived by Dave Smith, see http://www.amdmb.com/article-display...D=105&PageID=1)

For example, my XP2700+, when overclocked to 2340mHz, puts out the following watts:
68.3 X (2340/2167) X (1.775/1.65)^2 = 85.35watts

With my HS/fan (about 0.29°C/W) I can expect about a 24.8°C rise in temp over case (ambient) temperature. If my case is at 27°C, my CPU temp -- at 100% CPU output -- will be about 51.8°C.

I wrote a little Excel tool to do the calculations, PM me with your email address if you want a copy.

[cruiserlck]

I'm running the same cpu and motherboard. My 2500 is running as a 3200 by setting the fsb to 200 and the multiplier to 11. Just make sure you have memory that can hold up to the overclock , I'm using pc3200 with the speed set to 100 % . I would say that the heatsink and fan you've chosen along with the artic silver 3 should do the job nicely. Good louck and have fun with your OC !

[Arcuivie]

I have 1GIG PC3200 RAM, but how to I make it run at 100%, I check the mobo's manual, and it said the selections should be BY SPD, Auto, and a whole bunch of percentages, but all I can select are Auto and BySPD. Oh and what should be the resulting frequency for the memory.

[jmichna]

With regard to determining CPU HS/fan effectiveness, "100% CPU output" means run a program like Prime95, Seti@Home (command line client), or any "burn-in program that will force the CPU to run 100% of the time/no idle time (most of the time, a major fraction of CPU time is "idle time" and much less heat is produced).

In my initial post above, I was trying to provide a way to calculate "worst case" conditions to ensure the computer can handle the heat running any application.

BTW, Arcuivie, did you get the Excel file? Any questions?

[Arcuivie]

Yes, I got it, no questions, thanks a lot for it .

[Arcuivie]

Will overclocking potentially shorten the life of your CPU, even if you are keeping it pretty cool?

[jmichna]

Originally posted by Arcuivie
Will overclocking potentially shorten the life of your CPU, even if you are keeping it pretty cool?

I'm sure you'll get all kinds of responses here, but the reality is that "Yes" overclocking does shorten the CPU life, but -- for most of us... unless you do something stooopid and burn it up --- the life span is shortened to a degree that will not affect you.

For example, I had a Slot-A Athlon 700 running at 850mHz for about 2 years... about a year and a half ago, I sold the mobo/CPU/HS/Fan to someone who is still using it to run Seti, or some other folding app.

You may take a CPU from a projected 10 or 20 year life span to 10 or 5 years, but who cares... you will be replacing that CPU in a few years any way.

I have an original TBird 1200mHz/200mHz fsb cpu that has NEVER seen those parameters. It has been run at 1400mHz/266mHz since Day 1, and that is roughly 3 years ago.. It is my work horse. I use this CPU to test "dead" mobos.

[Arcuivie]

Well...say in about 2 or 3 years, after overclocking it for that long without actually upgrading it to the 3200+, will I notice a decrease in performance?

[jmichna]

Originally posted by Arcuivie
Well...say in about 2 or 3 years, after overclocking it for that long without actually upgrading it to the 3200+, will I notice a decrease in performance?

No. Electronics like CPUs either work or don't. Electronic devices follow a bath-tub shaped failure rate curve. In a population of CPUs, there will a number of CPUs which fail relatively early in their lifespan, those that don't fail will tend to perform as designed for a long period of time, until the end of the design lifespan, at which time a large number will begin to fail. The effect: (relatively) many failures initially, very few in the middle of their life, and (relatively) many failures at the end of their life span.