2500+ yielding errors…

I just bought an AMD Athlon 2500+ Barton. The CPU runs perfect at stock 1.83ghz and perfect at 2ghzish (166x12), but when i get to 2.166ghz (166x13)with about an hour of prime95 i will get a round off error. The system doesn't crash, however p95 will claim hardware error. The core never exceeds 45c. I am thinking it is an under voltage, because the vcore sits at 1.49-1.53 full load. Would upping the Vcore to about 1.7 make it more stable? The machine has an AMD recommended PSU rated to 300w.

Also, i noticed that everything in windows only picks up 64k of the L1 cashe. Would this be a buried setting in the bios or is windows just lying?

Abit NF7-S Rev. 2
AMD Barton 2500+ @2.166
Zalman CNPS7000A-AlCu
Biult by ATI 9500 PRO
Corsair (value select) 512MB DDR400
40 and 120GB WD IDE HDs

I take it your still on stock Vcore?

The Abit NF7 motherboard tends to (in my experience) under volt by .05v, which means when you set the voltage to 1.7v in the BIOS your actually running the chip at 1.65v (or the stock voltage for the Xp2500+) . Use the hardware doctor that comes with the mobo (software) to check it.

I would definetly set it to 1.7v (prob 1.65v to the chip) and see what she will run at. Zalman cooling isint the best , nice and quiet but i wouldnt push the voltage up to much and watch the temps.

You should also post your Power Supply as thats important too.

Try 200x11 @ 1.7v (BIOS setting) and try prime95......

The power supply is a startech.com AP350-X, however it says that it can only supply 279 for the 3.3v, 5v, and 12v. It is, "recommended" for the AMD athlon k7.

The machine is in a temporary case. I have not decided what case i want, however i do plan to get at least a 350W PSU.

If your getting a PSU try to get a reasonably good one like an Enermax , forton , or an Antec True Power........

Its very annoying when something like a PSU is hindering your overclock. The rest of your system looks good .

You should try min of 200mhz FSB to take advantage of your Ram. Your CPU and Mobo will have no probs doing that.

Let us know how you get on, cpu looks like a good one so far.

sorry to join this thread, but i'm also having some issues w/ OCing my 2500+ rig that i just built (first one =p )

my setup is on my sig... running at 166x11 (default), 1.65 Vcore (default). RAM currently at default 2.5-3-3-8, 2.6Vdimm...

i tried going straight to 200x11, 1.70Vcore (2.5-3-3-8, 2.6Vdimm) after running it on default for ~20 hours. then i ran prime95, and it gave a hardware failure error as well after 5+ hours.

so i tried increasing it to 1.75Vcore (2-3-3-7, 2.7Vdimm ...which passed memtest86), and it halted on another hardware failure error after 6+ hours.

some questions:

1) how big of an impact does my memory OC have an effect on the failures?
2) what's a good stepping for Buffalo Tech pc3200 CH-5 in dual channel on a ASUS A7N8X-Deluxe mobo?
3) any other recommendations on OC'ing my 2500+ to 3200+ safely w/ stability?
4) how many hours should i run prime95 w/o getting errors for?

thanks in advance.

i tried going straight to 200x11, 1.70Vcore (2.5-3-3-8, 2.6Vdimm) after running it on default for ~20 hours. then i ran prime95, and it gave a hardware failure error as well after 5+ hours.

Click to expand...

An increase of .05v to the Vcore should in my experience be enough to stabilise the cpu when is is crashing after 5 hours (actually normally .025v is enough). Try relaxing your ram timings and upping your Vdimm to 2.8/2.9v . Just for testing try 2.5 -4-4-8.

This should eliminate the Ram from the equation. What is your cooling setup? are you monitoring your temps??
I would be betting on either it being down to a Ram error or a Temp problem. Your PSU should be perfect. Have heard of people passing memtest but failing Prime95 (on a memory fault).

cooling setup... Silent Boost + AS3 on the cpu, then added an extra "front" YS-Tech 120x25mm fan (which is more in the middle of the box)

pretty much it...(hope that answers your question)

as for temps, it's at 43/51 w/ MBM5

so for the next step, you recommend the following?

200x11
1.75Vcore
2.5-4-4-8
2.8Vdimm

...i'll wait for your reply just to be sure. thanks.

I had problems with my setup doing 200*11, then I did some testing with mem86, I was able to go with my Corsair PC3200 XMS only 198 fsb with 2-3-3-6. I have Barton 2500, 198*[email protected].

AMD 2500@198*11, 1.75v, Volcano 10(sucks), 43/50 Prime95
512mb Corsair PC3200
ASUS A7N8X DLX., 2.0
Antec SL 350

hey col_loki,

how long should i run that setting in prime95 for? 6, 12, 24, x hours?

if it is successful...what step do i do next?

thanks in advance.

The saying goes: "12-hour Prime95 Torture Test stable system."

Don't be too shy to hit 1.8 volts by gradually upping it in 0.025 increments.


To test the stability of overclocked CPU, download the latest bug fixed version of Prime95:
http://www.mersenne.org/freesoft.htm

Double click on PRIME95.EXE to start the program.

Just Stress Testing (if prompted) > OK >
Options > Torture Test > Blend (if prompted) > OK


The program should not give any errors.
It may be necessary to run the program 12-24 hours to make sure an overclocked system is stable (no program errors displayed).


If you get errors only after several hours, this is a result of slight instability because the system is running with little or no margin. It's stable enough to boot and to be moderately stressed, but as soon as the system is under enough load to go over that critical point, it will freeze. To be 100% stable, Prime95 should run 12-24 hours without any errors.

The point of testing is to see if you get errors or not thus testing the stability. The meaning of errors themselves is not as important.


Running Prime95 Torture Test for 5 to 30 minutes is enough to get a feeling about general stability. If it seems to be stable, increase the FSB (with 0.025V Vcore increase if needed), or increase the multiplier by 0.5.

Reboot and run Prime95 Torture Test for 5 to 30 minutes and repeat this until the Program displays errors.
It's then time to back down and repeat the Torture Test until there are no errors for at least 12 hours.

It's OK to use the computer while Prime95 Torture Test is running in the background.

200x11 , 1.75Vcore , 2.5-4-4-8 , 2.8Vdimm

Click to expand...

Yup that looks like a starting point alright...... Many people use 11x200 as a benchmark with the Xp2500+ , ie see what voltage it will take to get it stable. With those ram timings your memory shouldnt be a problem.

IMO Getting it stable at say 2.2ghz is the way to go first. Then get into overclocking a little more, find your Max FSB that your Ram will go to ....... tweak the multiplier and find what your CPU is able for and how much voltage it will take. Then tighten your Ram timings and your sorted.

Its definetly a nice starting block.......

As for Prime stable .... exactly what c627627 said

for memtest86... how many PASSes should be complete to say that the mem is stable?

is there a memory timing guide somewhere in these forums...? i have been to so many OC-related forums these couple of days that i forgot where that guide was. i just would like to figure out the jargon and stuff (gg 5 years of computer engineering down the drain ^^ )

Normally people loop memtest for 8hrs or more to insure its totally stable. Prime95 will normally give you a very good indication it your timings are stable.

I take it your system is running prime stable ?? You could try to use the 11.5multi and see it thats stable....... great place to start by the way.

hey loki,

so far ... no =| my sys. is having trouble passing prime after 5+ hours on 200x11, 1.75V

i ran memtest on 8-4-4-2.5/2.8V & 7-3-3-2/2.8V for just 1 pass yesterday--100% pass. so i told my roommate at home (cause i'm at work) to run it again...probably check when i get home.

...any suggestions on what i should do w/ the cpu if memtest does pass after so-and-so hours???


(i hope its not the way i put the AS3...it was a tight fit putting the SilentBoost on the cpu/mobo because of some capacitors.)

If prime95 is lasting 5hours that means your system is very close to being 100% stable. If its the CPU thats the problem up the Vcore to 1.775v and run prime95 again.

What is your PSU like?
Are your Temps ok ?

If the system is highly unstable prime will fail under 1 min. 5 hours is a good indication...... your close.

"as for temps, it's at 43/51 w/ MBM5"

psu is stock Antec True380S

... 11x200 (if i get to it to stabilize) is good for everyday usage right?

quick update...

200x11, 1.725Vcore, 11-3-3-2 @ 2.7Vdimm

Click to expand...

ran prime for 18 hours, 24 minutes - 1 errors, 0 warnings.

good enough to call these settings stable, or should i pass the 24-hour mark ??? ^^

thanks in advance.

IMO I would go for 24-48 hours or prime and @least 6-12 of 3dmark.

sooo... up Vcore 0.025 till i go over 24+ hours ???

my ram is okay at 11-3-3-2 setting for everyday use correct ??? (it passed memtest86 w/ a handful of loops)

About the cache quiestion, in my sig there's a link to GCPUID, get that and run it. See what it reports. should be 64KB x 2 for L1 and 512KB for the L2