Overclocking Query

Alkers

Spec as in sig.
Basically when I put a 5:6 divider on my memory I can run at 2.5Ghz (278Mhz FSB *9). When I put the divider to 1:1 I can't boot at anything over 265Mhz FSB and is only stable at 262Mhz. I have tried running the memory at 213Mhz and it won't boot at all . Would it be the mainboard holding me back? My ram is rated for 300Mhz and I have it at the correct voltage and timings, and I was perfectly stable before at 278Mhz but with my memory running at around 230Mhz. Lost on this one, what do I have to do to get the CPU @ 2.5Ghz with the ram @ 278Mhz???

conzy

What exactly is the problem??

You had a stable overclock and now its unstable?

And when you say a 5:6 multiplier do you mean fsb:ram??

Did you loosen timings? Maybe you have to increase voltage to reach 300mhz FSB

Alkers

I had a stable overclock but with the memory at a lower speed due to the 5:6 Ram:FSB divider. My memory is rated for 300Mhz @ 2.85/2.9V @ 2.5-4-4-8 and I have it at theese setting except it's at 2.85V as this is the max on my mainboard. At the moment I can't get it past 262Mhz. I know it's not the cpu because I had that running at 2.5Ghz (278*9) on the same board, just with memory running slower.

conzy

That extra half volt would go a long way..............

So you are running 9*262= 2.36ghz at the minute?

Will your CPU do 2.6ghz??

What voltage do you have it at?

If so Try run 10*260mhz= 2.6ghz, that would be better than 9*278 on a 5/6 divider.

Alkers

I have the CPU @ +6.6% Voltage. I've had it running at 2.5Ghz before. I'd do that alright but 9 is the highest the multi will go (amd 3000+).

conzy

Ah sorry, I never saw that:rolleyes:

I dont think there is much you can do then other than run a divider, becasue your ram is maxed out at its current voltage:

http://www.cluboverclocker.com/reviews/memory/pdp/patriot/index.htm

Speed Memory Timings Voltage Settings
PC3200 (400MHz) 2-2-2-5-1T 2.6-2.7v
PC3500 (436MHz) 2-3-3-6-1T 2.6-2.7v
PC3700 (466MHz) 2-3-3-6-1T 2.7-2.8v
PC4000 (500MHz) 2.5-3-3-7-1T 2.75-2.85v
PC4200 (533MHz) 3-4-4-8-1T 2.85-2.95v

266mhz is the fastest 1:1 FSB you can get!

Thats why its unstable at anything above that.

Find your CPU's max overclock, and set a divider that will bring your ram as close to 260mhz (DDR520) as possible, Then work on tightening timings.


Thats the best performance you can get from your current setup;)

Alkers

I don't understand why I cant run 278*9???My ram is rated for 300 so why camt I boot at 278???

conzy

Its not rated for 300mhz!

Look at the table I posted, they are the max overclocks that your ram can get, If you cannot give it anymore Vdimm, you are stuck at 260mhz.

If they same divider as before isnt working now, you may have damaged your ram, use a larger divider to slow down the ram.

Alkers

It is definately rated for mhz
http://www.patriotmem.com/products/specs/pdc5121g4800_xblk.pdf
That's why I'm at a loss on this one.

conzy

Ok, thats different than the ram I thought you had,

But it still needs 2.9volts to do DDR600

And it needs 2.85volts to do DDR500

And you are topping out at around DDR550, So you need the extra .5volts to do DDR600.

What mobo do you have? Is there a Beta/ cracked bios that allows more than 2.85 vdimm??

Alkers

It's a MSI K8N Diamond - was top of the line when I bought it. Wouldn't know where to check for a hacked BIOS but as far as I know I have the latest one. I reckon you must be right about it just being down to that extra .05V as I cannnot think of anything else.

conzy

It is the .05volt;)

It wont run under volted, what timings are you running as we speak??

Your ram is rated for 3-4-4-8 at 2.9volts for DDR600

So its possible to get 2.7ghz with a 1:1 OC.

Have a look on google for "MSI K8N vdimm mod" or something

*edit*

Alkers

2.9-2.85 is 0.05V - that's why I wrote that off.
Ram is at 2.5-3-3-8 - I'll see if loosening them makes a difference and have a look for a vdimm mod.
Thanks for the help.