Overclocking QX9650 on Asus P5G41T-M LE

[THX-UltraII]

Hi,

I just made a good deal on a QX9650 processor which has an unlocked multiplier. This is great for my Asus P5G41T-M LE which seems to have a limitation of the FSB of 399 (I used to own a Q9450 and with my board I just could not get the FSB past 399 no matter what I did with voltages etc.).

I m on watercooling so I want to give 4.0Ghz a shot with the QX9650. What I want to know is how to do this so I have some questions about this


1. CPU VID
With the QX9650 an option comes available in my bios when changing the multiplier from it s default 'auto' setting to a manual multiplier. This is the so called CPU VID which can be set from 1.1375V - 1.6000V. Can someone tell me what this does and what recommended voltage is to set it on looking at my goals of 4Ghz? And also what the maximum safe voltage is to put it on?

2. FSB
What the best/highest performance value to put the FSB on (in my BIOS the FSB is called CPU freq):

333 (default) with multiplier 12 which results in 3.996Ghz
348 with multiplier 11.5 which results in 4.002Ghz
363 with multiplier 11 which results in 3.993Ghz
380 with multiplier 10.5 which results in 4.000Ghz
399 with multiplier 10 which results in 3.990Ghz

I know these values also have their influence on the speed of my DDR3 memory, 2x2 GB Kingston KVR1333D3N9K2/4G. (With my previous q9450 I owned I ran my system on FSB 399 with x8 multiplier (3.2Ghz). With this setting my memory speed was 1596Mhz and it was stable).

3. MEMORY VOLTAGE
I can set this from 1.21000 - 2.47000. I assume it will depend on the FSB I choose if I can leave it on 'auto' (default) or increase it to max. 1.6-1.7?

4. NB VOLTAGE
I can choose from 1.12500 - 1.51875 for this. What does it do? What would you guys recommend with the goal (4Ghz) I have? And what the max safe voltage?

5. VTT VOLTAGE
I can choose from 1.20000 - 1.59375 for this. What does it do? What would you guys recommend with the goal (4Ghz) I have? And what the max safe voltage?

6. CPU OVER VOLTAGE
I can choose from 0.01000 - 0.63000 for this. What does it do? What would you guys recommend with the goal (4Ghz) I have? And what the max safe voltage? Also a not selectable option called 'Offset Sign' appears with a '+' when switching from 'auto' to manual.

7. SB 1.5V VOLTAGE
I can choose 1.5V or 1.6V. What does it do? What would you guys recommend with the goal (4Ghz) I have?

Thanks for all input!


Hardware/Software:
Asus P5G41T-M LE with 0901 firmware
Intel Core2Quad QX9650 with unlocked multiplier
2x2 GB Kingston KVR1333D3N9K2/4G
MSI GTX460 Cyclone 1GB GDDR5
OZC ModXStream Pro 600W
W7 64-bit

Some screenshots:
http://imageshack.us/gal.php?id=sZankp2 ... auZo83b2pU

[Major_A]

Here's my personal experiences with a socket 775 Core processor. Find the overlock you're happy with (say 4.0GHz). Getting there only adjust the CPU VID. This should make you stable. I don't recommend going over 1.4V unless you're on a good water cooling loop (I don't consider a boxed unit good water cooling). Once you have your overclock start throwing programs at the machine and see if you can get an error. If you do then you probably just need a little more voltage, this is where the CPU Over Voltage probably comes in handy. You can add very small amounts of voltage rather than the larger jumps just using the CPU VID. If that doesn't work then start playing with NB, VTT, SB voltages. Otherwise leave them on auto. When you start overclocking try to keep your RAM as close to it's stock speed as possible, use a multiplier if you need to. After you find the overclock you like (i.e. 4.0GHz) then you can play with the RAM. You can try to make it run faster, either tighter timings or faster speeds. That's where you would need to play with the Memory Voltage.

Hope that helps and good luck.

[THX-UltraII]

Here's my personal experiences with a socket 775 Core processor. Find the overlock you're happy with (say 4.0GHz). Getting there only adjust the CPU VID. This should make you stable. I don't recommend going over 1.4V unless you're on a good water cooling loop (I don't consider a boxed unit good water cooling). Once you have your overclock start throwing programs at the machine and see if you can get an error. If you do then you probably just need a little more voltage, this is where the CPU Over Voltage probably comes in handy. You can add very small amounts of voltage rather than the larger jumps just using the CPU VID. If that doesn't work then start playing with NB, VTT, SB voltages. Otherwise leave them on auto. When you start overclocking try to keep your RAM as close to it's stock speed as possible, use a multiplier if you need to. After you find the overclock you like (i.e. 4.0GHz) then you can play with the RAM. You can try to make it run faster, either tighter timings or faster speeds. That's where you would need to play with the Memory Voltage.

Hope that helps and good luck.

Thanks for your reply.
I m trying to reach 4Ghz without needing to raise the FSB. This way my RAM can run on it s default 1333Mhz speed and I don t need to adjust the Memory Voltage or NB Voltage correct? (NB Voltage is needed when you raise your fsb correct?).
Ok, I just put my CPU VID on 1.3725 which is the maximum intel spec I think. Is this ok or should begin with lower like 1.25 or something between 1.3000 and 1.3725?
With 1.3725 my PC did not boot at all. I bumped the CPU Over Voltage and my pc started up again but hang during windows startup. But before I go further I need to know what range I would be looking for to set the CPU Over Voltage on (CPU OVER VOLTAGE can be changed from 0.01000 to 0.63000 with increments of 0.01000).
And WHAT is the axact difference between the CPU VID and CPU Over Voltage? Is CPU VID+CPU Over Voltage=actual cpu voltage? So eg. CPU [email protected]+CPU Over [email protected]=actual cpu voltage of 1.4425v?

[Major_A]

And WHAT is the axact difference between the CPU VID and CPU Over Voltage? Is CPU VID+CPU Over Voltage=actual cpu voltage? So eg. CPU [email protected]+CPU Over [email protected]=actual cpu voltage of 1.4425v?

That's how I interpret those values. I had my Q9550 at 4GHz and I never adjusted the NB/SB/VTT voltages. I only had to adjust the CPU VID (on Gigabyte VCore). I want to say for the final 3.83GHz I ran 24/7 I used 1.325V to get there. What are you using to cool your CPU? It might be worthwhile to buy a better/new aftermarket cooler.

Can't really go wrong with this cooler. If you decide to pick up a new cooler make sure it has a backplate.
http://www.newegg.com/Product/Product.a ... 6835233082