Overclocking a dual core X3800 on the AN8 SLI Premium

[dangel]

So... i'm new to this A64 lark and having spent all weekend building the machine, i haven't had time to overclock it. My last machine was a overclocked AthlonXP but things seem a bit more complicated on this platform. Are the following true?

1. FSB x HYPERTRANSPORT MULTI = HYPERTRANSPORT SPEED (MHZ)

2. FSB X CPU MULTI = CPU SPEEZ (MHZ)

I think so. Next question - i want to run my CPU at 2.4ghz so i'm thinking:

240MHZ FSB x 10 (cpu multi) = 2400mhz

HT Multi 4 x 240mhz FSB = ~960MHZ

But my real quandry is the memory - i don't want to run this at 240mhz, but 200mhz (DDR 400 effective) is this possible by setting the Max Memclock to 'DDR333' in the bios?

I'm getting this from an article which claimed 2.4ghz was possible with stock memory speed (200mhz/DDR 400) but he wasn't very clear on his settings and i can't figure out what 'DDR333' actually does - is it a memory divider reducing to 83.3333333% of FSB?

To quote:

"With very little effort and even less drama, I was able to get the X2 3800+ running stable at 2.4GHz by setting the HyperTransport clock to 240MHz. The Asus A8N-SLI Deluxe mobo on our test system was giving the X2 3800+ about 1.31V by default. I turned that up to 1.3375V, backed the HyperTransport multiplier down to 3X, and the X2 3800+ seemed quite happy.

Now, that's a sweet overclock all by itself, but hitting 2.4GHz has the added benefit of bringing everything into line. When the memory clock is set to the proper divider for DDR333 operation and the HyperTransport clock is raised to 240MHz, the memory actually runs at 400MHz even. Lock down the PCI and PCI-E bus speeds using the motherboard's BIOS, and you're running virtually everything but the CPU and HyperTransport link at stock speeds. I was able to leave the RAM timings at 2-2-2-5, nice and tight. This is the sort of overclock I could live with for everyday use."

(http://techreport.com/reviews/2005q3.../index.x?pg=14)

Thanks for your help, i'm sure i'm on the right track - almost!

[Dougal]

First, burn your CPU in as it stands.

Run benchies till your eyes bleed. Make sure its perfect first.


Then the divider.

If you set it at 2:1 it doubles the FSB to get DDR400, the FSB is 200.
1:1 Same, 3:2 1.5x FSB 1:2 half.

So for you, if you run at 240FSB, you'll prob be best with the 3:2 divider.

[dangel]

This is the bit i'm finding confusing tho - i can't find the memory divider anywhere so i'm assuming it's the 'ddr333' 'ddr400' etc setting?