Confusion while overclocking...

[rjmiller]

So yesterday for the first time I decided to try to overclock my CPU and after spending a couple hours reading up on things I figured i was good enough to have a go at it.

First I tried using clockgen instead of BIOS (not the smartest idea) and I ended up with a:
Core Speed 2606.7
bus 217.2
Memory Frequency dropped from 201 to 173.8
Voltage from 1.4 to 1.52

These settings ran fine, but I decided I wanted to try it from the BIOS instead, well i couldn't figure out how to reset all the frequencies back to normal (Clockgen didn't set them back correctly). So instead I cleared CMOS manually.

Now this whole time I've been using CPU-Z to check all my information. Once CMOS was cleared everything was back to normal, or so I thought.

After changing the overclocking in BIOS to

227.04 x 11.5 (2611 mhz)
voltage 1.4 to 1.45

My coreTemp reader now reads the correct Frequency, however CPU-Z says my speed is 2498 mhz (217.2x11.5) with an HT of 651.7 instead of 1000.

Also, my memory Frequency is still at 178.4 instead of 201.

I know there are probably a lot of issues here, but any help would be great.

Info:

AMD Athlon 64 3800+ (Venice)
Asus A8N-SLI deluxe
2 GB Corsair Valueselect Clocked 333mhz (2.5-3-3-8)


If there is anything else you need to know, just post and I'll get it to you.

 

[GuitarDaddy]

Well your problem revolves around the use of 1/2 multi's which are not supported by A64 chips, they are a fabrication of the bios. Both utilities are half right, you are actually running 217x12=2.6ghz.

And your ramspeed of 178 is correct if your using the DDR333 memory divider which is perfectly fine if your using 4x512. I doubt you can get 4 sticks to run 217mhz.

Drop the multi to 11 and up the HTT to 237, 237x11=2607. That way with the DDR333 divider your ram will run close to stock.

 

[996GT2]

Originally posted by: GuitarDaddy
Well your problem revolves around the use of 1/2 multi's which are not supported by A64 chips, they are a fabrication of the bios. Both utilities are half right, you are actually running 217x12=2.6ghz.

And your ramspeed of 178 is correct if your using the DDR333 memory divider which is perfectly fine if your using 4x512. I doubt you can get 4 sticks to run 217mhz.

Drop the multi to 11 and up the HTT to 237, 237x11=2607. That way with the DDR333 divider your ram will run close to stock.

Yeah your motherboard shouldn't be allowing you to run 1/2 multis with an A64. Only certain newer AMD CPUs support 1/2 multipliers, such as the X2 Brisbanes. Other than those, running 11.5x multi won't work properly.

Since you have a 3800+, I would recommend you stick with the 12x multiplier to see how high of an OC you can achieve with it. Using the default 12x multiplier means you will be able to keep Cool and Quiet on, because if you turn down the multiplier to 11 and keep C&C on, the C&C can adjust the multipliers up to 12, meaning that your 2.6 GHz OC can sometimes turn into a say, 2.8 GHz one. This will kill stability, so if you're going to use a multiplier that is lower than 12, make sure you turn off cool and quiet in the BIOS.

When overclocking the CPU, set your RAM divider to the lowest your board allows to take RAM speeds completely out of the equation. Only when you have found your maximum stable CPU clock should you begin to adjust RAM speeds.

Oh, and make sure you turn off CPU/PCIe/SATA Spread Spectrum in BIOS. Keeping those on can seriously mess with stability.

Also, if you plan to run higher than around a 230HTT, you should adjust the HT Multiplier to 4x instead of 5x. This will prevent your HyperTransport bus from going much over 1 GHz. Similarly, if you plan to go for an HTT higher than 270 or so, you should change the HTT multi to 3x. Different boards can support different max HTT frequencies, so you should experiment a bit with that.

 

[rjmiller]

Alright, thanks for the advice, both of you. I will try those suggestions through the next couple of hours and see what happens. Thanks a lot.

 

[rjmiller]

When overclocking the CPU, set your RAM divider to the lowest your board allows to take RAM speeds completely out of the equation. Only when you have found your maximum stable CPU clock should you begin to adjust RAM speeds.

What do you mean by this?

I was looking around in BIOS and are you saying that I should lower my RAM speed from 333mhz down to 217mhz or something? or are you talking about changing to timing speeds from 2.5-3-3-8 to something different?

 

[heyheybooboo]

if I understand the question your ram freq is effectively 2x your bios setting PLUS the percentage increase you make to your cpu freq.

he is suggesting that you cut back your ram freq to something like 133MHz and then start clocking up your cpu freq. when your reach your max on the cpu freq you can do the *math* to determine your best ram freq.

edit: sorry . . . . you probably want an example

your cpu freq is 200 (x12) = 2400MHz

increasing 25% = 250 (x12) = 3000MHz

ddr333 is nominally 166(x2)

if you set you ram freq to 133 . . .

133 x 1.25 = 166.25MHz(x2) = 333.5mhz!


your ht is 200(x5) = 1000mhz (x2) = 2000mhz

you never want to exzceed 1000mhz on your ht so if you increase the cpu freq . . .you have to reduce the ht multiplier

250 (x4) = 1000mhz (x2) = 2000mhz

got all this ???

 

[GuitarDaddy]

On that board the memory settings are DDR400,333,266,200. DDR200 is the lowest setting if I remember correctly, but you won't need to use that unless you are going to drop the multi. With the 12x multi you won't need anything lower than DDR333

 

[996GT2]

Originally posted by: rjmiller

When overclocking the CPU, set your RAM divider to the lowest your board allows to take RAM speeds completely out of the equation. Only when you have found your maximum stable CPU clock should you begin to adjust RAM speeds.

What do you mean by this?

I was looking around in BIOS and are you saying that I should lower my RAM speed from 333mhz down to 217mhz or something? or are you talking about changing to timing speeds from 2.5-3-3-8 to something different?

What I mean is that you should keep your RAM at a low divider (i.e. so it's underclocked) while you are overclocking your CPU. This way, if you get any stability issues, you will be sure that it's not the RAM, since your RAM will be running at less than its rated speed. This is especially important if you are going to run a high HTT/lower multiplier setup. As far as timings go, just leave them at the stock 2.5-3-3-8, since ValueRAM isn't likely to run at CAS 2 at 400 MHz (you could try this down the road, but get the CPU overclocked properly first before you start adjusting your RAM).

 

[rjmiller]

Alright, so in the end the desert is just too hot of an environment to be overclocking with stock cooling, besides I really couldn't get it to stay stable anyway and I don't have a backup computer. So i have returned to my original settings...However, I am running into one small issue. My RAM speeds are reading at 160mhz as opposed to 201mhz. 160 mhz is what CPU-Z is showing me. Is this technically correct, is there any way to fix it and if I can't will I run into any errors later on. I've tried removing and replacing the RAM when the machine is off and that didn't seem to do anything (I'm not sure if it should have anyway)...

Any help would be great, thanks.

 

[GuitarDaddy]

Set your mem speed back to DDR400 in bios

 

[rjmiller]

cool, thanks. That did the trick.