What Dram Frequency..don't understand?

Guinny · 15 May 2009 at 17:44

Sorry for the noobish questions but it's been a long time since I upgraded or overclocked!

I have an ASUS P5B Intel Q9450 2.66ghz and Kingston's HyperX 4GB DDR2-8500 CL5.

The bios options for the Dram frequency are Auto/667/833/100/1111/1333

The multiplyer has option of 6 -8

I can run comfortabley at 400mhz FSB giving me a CPU speed of 3.2ghz

My question is what should I set the Dram frequency to?

I tried it set at 1333 which ran but wouldn't overclock.

To be honest I don't understand the whole divider/fsb/Dram T1 T2 thing!

toon_mad · 15 May 2009 at 17:51

T2 is considered more stable for overclocking.

i try and get the ram to run at its native speed while overclocking (i.e if your ram is meant to run at 800mhz, keep it at that, same with 1000mhz, 1066mhz etc), which i think is a divider of 1:1, you should only start overclocking the ram when you have a prime95 stable pc (at least 7hrs i reccomend).

once the cpu overclock is stable, go for the ram overclock

Guinny · 15 May 2009 at 18:31

Thanks...what is the native speed of my ram?
If it is 1066 then what do I select?

OzZie · 15 May 2009 at 18:41

1066 is 533mhz, although depending on how the ratio falls, you may go slightly over or slightly under this value.

Guinny · 15 May 2009 at 19:05

OzZie said:
1066 is 533mhz, although depending on how the ratio falls, you may go slightly over or slightly under this value.

I still don't understand what settings I adjust.
I have three places to change settings.
1.FSB
2. Dram Frequency
3. CPU ratio

So waht fsb should I select if I put the Dram at 533 -(200mhz?)
Do I keep the ratio at 8

kerrgreg · 15 May 2009 at 19:25

Yes set the FSB and cpu ratio to what you want your overclock to be, eg "400mhz FSB giving me a CPU speed of 3.2ghz"

you know that works so then set your ram to what you can run it at eg 1066 or as close as you can get your board should tell you wht the freq will be so set it as close as you can get to stock

Corasik · 16 May 2009 at 02:06

With most motherboards, when you overclock the cpu, the ram is automatically dragged up as well, this can easily lead to massively overclocking the ram, without even realising it.

The stock speed of a Q9450 is 333mhz (FSB), your overclock is 20% approx, so if you pick 833 ram, you will probably find the ram running at 1000mhz, pick 1000 and the ram will likely be clocking in at 1200, which your ram would probably object to.

667 is the "Native" speed for 1:1 FSB/Memory bandwidth (for a Q9540), and with your overclock the 667 setting will give you a memory speed of 800 (exactly double your overclock). This should allow you to push your CPU to its limits without any worries that your rams limiting anything. Once you find your CPU's limits, you can try faster ram speeds.

Surprised it even booted at 1333 ram, considering the memory is rated for 1066. Perhaps you have some good sticks there, should be some fun clocking ahead.

I understand that some motherboards include the "overclock" factor in their memory speed menu. others do not, easy to check, just use cpu-z and see what frequency the ram's running at. (It will be the MHZ, so half the expected number for the DDR modules IE DDR1066 will have a frequency of 533mhz)