Folding Forum

7up1n3 wrote:I would avoid using the OEM cooler even if you're not overclocking.

I have 7 Q6600s. 6 use OEM cooling and run @ 3.2GHz or higher. The one that uses a Tuniq Tower cooler does run 10-20C cooler but not any faster.

Keeping the northbridge cool is more of an issue than CPU temp.

Well, you guys have definitely talked me into the Q6600. I'm still trying to figure out the relationship between the processor, mobo, and memory as far as fsb, and multiplier. That's a little shady to me. I don't really get the 1:1 relationship that I am supposed to be looking for.

The CPU runs with a default FSB (frequency of the bus between CPU and the rest of the machine). For the Q6600 this FSB is 266 MHz.

Your RAM run also run at a frequency (400 MHz for DDR2 800, 533 MHz for DDR2 1066). On most systems, this frequency is different from the FSB. For a Q6600 with DDR2 800 memory, FSB will be 266 and RAM wi run at 400 ...

When we talk about the 1:1 ratio, it allow you to synch the RAM at the same speed of FSB ... this will prevent the RAM from running higher than it's nominal frequency. If you have DDR2 800 and a Q6600, you can go up to 400 MHz FSB, which is 3.6 GHz for the CPU (default multiplier is 9 on this CPU). If you don't have the 1:1 ratio, you will need a very good and expensive memory.

toTOW wrote:The CPU runs with a default FSB (frequency of the bus between CPU and the rest of the machine). For the Q6600 this FSB is 266 MHz.

Your RAM run also run at a frequency (400 MHz for DDR2 800, 533 MHz for DDR2 1066). On most systems, this frequency is different from the FSB. For a Q6600 with DDR2 800 memory, FSB will be 266 and RAM wi run at 400 ...

When we talk about the 1:1 ratio, it allow you to synch the RAM at the same speed of FSB ... this will prevent the RAM from running higher than it's nominal frequency. If you have DDR2 800 and a Q6600, you can go up to 400 MHz FSB, which is 3.6 GHz for the CPU (default multiplier is 9 on this CPU). If you don't have the 1:1 ratio, you will need a very good and expensive memory.

So, since I don't plan on ever over clocking past 3.4, then ddr2 800 will be perfect for me, correct? And when I'm overclocking, I should be trying to achieve this 1:1 relationship?

stalker wrote:

toTOW wrote:The CPU runs with a default FSB (frequency of the bus between CPU and the rest of the machine). For the Q6600 this FSB is 266 MHz.

Your RAM run also run at a frequency (400 MHz for DDR2 800, 533 MHz for DDR2 1066). On most systems, this frequency is different from the FSB. For a Q6600 with DDR2 800 memory, FSB will be 266 and RAM wi run at 400 ...

When we talk about the 1:1 ratio, it allow you to synch the RAM at the same speed of FSB ... this will prevent the RAM from running higher than it's nominal frequency. If you have DDR2 800 and a Q6600, you can go up to 400 MHz FSB, which is 3.6 GHz for the CPU (default multiplier is 9 on this CPU). If you don't have the 1:1 ratio, you will need a very good and expensive memory.

So, since I don't plan on ever over clocking past 3.4, then ddr2 800 will be perfect for me, correct? And when I'm overclocking, I should be trying to achieve this 1:1 relationship?

Yes. Most motherboards are more stable with 1:1. DDR2-800 is perfect for that system as very few Q6600s are getting higher then that on air. There are a lot of good overclocking guides, just google them. Here is a quick overview. Use at your own risk and know what you are doing...I don't.

There are a lot of options in the bios, but Vcore, FSB, RAM, and CPU Multi are the only ones you need to mess with to get a basic OC. Before you start messing with these you need to make sure that your system is setup correctly. This means checking the fan monitoring/speed control, RAM voltage (VDIMM), locking the PCI/PCIe clocks, etc. Your default Q6600 clocks will look like this approximately (you MB may report "auto" for these):

FSB= 266Mhz
Intel FSB rating = 1066 (hence quad pumped...4x266)
CPU Multiplier = 9x (thus, FSB x CPU_Multi = CPU Speed: 266Mhz x 9 = 2400Mhz = 2.4Ghz)
RAM = DDR2-667 or DDR2-800 (probably DDR2-800, but is MB specific)

Once your system is up and running at the stock settings (make sure you have a accurate temp monitoring program like everest or cpucore; others give bad info for quads), you should see several temps:

CPU:
Core 1: max temp for each core is 71C!
Core 2:
Core 3:
Core 4:
Motherboard:
PWM: <100C
Research your MB and find what the temps should be. From now on you monitor them always. Note that the CPU freq/speed of 2.4Ghz may show up as less if speedstep is enabled. Disable EIST in the bios and it will stay at 2.4Ghz.

Now change the RAM setting to the lowest (should be 1:1 or labeled as DDR2-533 for now). Reboot. Should look like this:

FSB: 266Mhz
Intel FSB rating: 1066 (4x266)
CPU Multiplier = 9x (9x266Mhz = 2.4Ghz)
RAM = DDR2-533 (2x266)

Congrats! You just lowered your systems performance! Don't worry we will be changing that soon. Now do you see the relationship between each of these? Try this if you don't. Change the CPU Muliplier to 6x. Reboot. Should show up like this:

FSB: 266Mhz
Intel FSB rating: 1066 (4x266)
CPU Multiplier = 6x (6x266Mhz = 1.6Ghz)
RAM = DDR2-533 (2x266)

Now with the RAM at DDR2-533 and the CPU multiplier set at 6x, lets see how how the FSB will go. Go in 10Mhz increments or something logical, opinions differ, until the computer won't boot. Write down the FSB value. My Q6600 looked like this:

FSB: 470Mhz
Intel FSB rating: 1880 (4x470)
CPU Multiplier = 6x (6x470Mhz = 2.82Ghz)
RAM = DDR2-940 (2x470)

Odds are you won't get much higher then 400Mhz with DDR2-800, but that won't be a problem (400Mhz FSB x 9 = 3.6Ghz, Intel FSB rating = 4x400 = 1600Mhz, and DDR2-800 RAM). Check you temps at each step and make sure they are ok. Now set the FSB to 266Mhz and the RAM to DDR2-800. Now increase the FSB until the RAM is the limiter. Write that down. Now you know how high the FSB and RAM will go without causing a problem. Now set the CPU Multi to 9x, the FSB to 266Mhz, and RAM to 1:1. Up the FSB till you get the OC you want or temps give out or won't boot, etc. Test for 24hrs with all four cores loaded (I like Prime95 25.3, but opinions vary). If it fails, lower your OC. Monitor your temps always. This is the price you pay to OC. If things aren't working like they are suppose to (random reboots, errors, etc.) lower your OC.

Monitor Folding@Home closely. If you aren't finishing WUs, lower the OC. Don't be turning in bad units for the sake of a 100Mhz or so. Doesn't help anyone.

stalker wrote:So, since I don't plan on ever over clocking past 3.4, then ddr2 800 will be perfect for me, correct? And when I'm overclocking, I should be trying to achieve this 1:1 relationship?

It's not essential to run 1:1.

I get the best stable performance with the following numbers:

FSB=368 Multi=9 or 9X368 = 3.31GHz
RAM using 2.5 multiplier = 2.5X368 = 920MHz

Most DDR2 800 RAM will run @ 920MHz

NOTE:
A RAM multiplier of 2 is the setting that will give you the 1:1 ratio. I point this out because it that is the way most motherboards allow you to set RAM frequency.

ALSO:
"Expensive" DDR2 1066 RAM is really DDR2 800 RAM packaged differently and "hopefully" binned better.

Yes this is reasonable until 3.4 GHz ... but on my watercooled systems, this is the minimal frequency