OC'ing my 4000+

[StillwaterIT]

I overclocked my a64 4000+ from 2.4ghz (200mhz fsb) to 2.52ghz (210mhz fsb), and it ran stable for about 6 hours, then programs started crashing, and eventually I got a bluescreen. My cpu voltage was 1.5v and my ram voltage was 2.7v. Temps never went above 38C at 100% and idle temp is 23C (room temp is 68F, brrrrr)

Any suggestions? Up the ram or cpu voltage? I dunno...

 

[Nihsnek]

I OC'd my 4000+ to 2.8ghz using 1.5v...and my ram is using like 2.675.

You could try raising your voltage by the smallest amount, run memtest for ram, then run Prime95 and see what you get. Remember, all CPUs are different, so 2.52ghz may be your max.

 

[reggie_da_man]

Well what kind of ram are you using?

 

[Nihsnek]

Oh yea, you might need to apply a divider on the FSB:RAM ratio. For example: I changed my ratio to CPU FSB/15. So when my CPU is running at 2945MHz, my ram only runs at 196MHz(it's rated at 200MHz). This will only help if your RAM is holding you back...

 

[StillwaterIT]

I just realized i was running 200mhz at 2.5,3,3,7 instead of the default 3,3,3,8. So I just now set it to 3,4,4,8 and clocked up to 210mhz for cpu AND ram, and running prime95... I'm crossing my fingers.. =)

My mobo doesn't support dividers, but you can manually set ram bus speed. It works the same as a divider, but not quite as nice.

 

[StillwaterIT]

Well this is wierd... I now have my cpu up to 2700mhz, 225x12, and apparently what I thought was manually setting the bus speed, is in fact a memory divider. Right now I'm running at 225x12 cpu, and 180mhz on the ram. Kinda wierd though...

Also, when I set my cpu voltage in the bios, cpuz always tells me I am at 1.4v instead of whatever voltage I set it at. The bios says one thing, cpuz always says 1.4v. What is that all about?

 

[StillwaterIT]

It boots at 2760mhz, but prime95 errored within 4 minutes.

Final OC: CPU: 225x12 @ 1.45V, RAM: 180x4 @ 2.8V / 3,3,3,8

 

[Nihsnek]

Always go with the BIOS for vcore readings. Try EVEREST Home Edition for more OC'ing/temperture information. (EVEREST isn't supported by the makers, just google "EVEREST Home edition download" and you'll get some links).

You have a FSB/RAM ratio on if your ram is running slower than your CPU. If your sure that your CPU maxes out at 225, then try making the divider smaller to boost your RAM speed. (if you have good RAM, you might be able to OC it a little bit, depends on the model/maker though).

Woah, you might want to lower then voltage to your ram. Mine is running at 210MHz and only using 2.675 volts. If you do lower it, run Memtest to check for errors, then Prime95.

Summary:

If you really have a fsb:ram divider on, and your CPU can only handle 225 with plenty of volts, then your CPU is at it's max.

If you have NO fsb:ram divider on, your ram is running at the same MHz as the CPU, and you can't OC anymore...it's most likely the RAM holding you back.

EDIT: Ah, you don't have dividers on your BIOS? Then keep the RAM at standard 200, and OC only the CPU...and find the max. Reverse the operation and find your RAM's max. Compare results and try to use a combonation of both to have a stable and decent OC.

 

[StillwaterIT]

On my DFI board, i had a wide range of dividers, but on this board it just says: 100,133,166,200. In actualality they ARE dividers 1:2, 2:3, 5:6, 1:1, based on what cpu-z says is going on.

I figure out the voltage problem. It defaults to 1.4v regardless of the set voltage, if cool n quiet is turned off. Turn it back on and it will use the user set voltage.

I've been figuring all of this out along the way, my board is really cheap and hard to understand compared to my dfi lanparty board.

Is 2.8V too high? It really doesn't like anything under 2.7 for sure. At 2.5v I'll get OS errors.

 

[Nihsnek]

Well...2.8v is the MAX you should go on the RAM. If I were you i'd try lowering it...i'd personally rather undervolt something than overvolt it.

Undervolt = possible crashes, reboots, fixable unless it corrupts some data...which i've never seen

Overvolt = lots more heat, strain hardware more, life-time goes down, chance of killing hardware