Corsair 8500C5 and ASUS P5W DH -- need help setting up

[jg0001]

So I bought the $4XX Corsair 8500 C5 memory (the one anandtech and others seem to love). Anyway, I'm REALLY not sure how to set it up to use it fully. I'd really like a few examples (DETAILED FOR THE P5W DH that layout what settings to try, IN FULL).

Setup:
ASUS P5W DH Deluxe mobo (1305 bios)
e6700 processor OC'd to 3.5Ghz (350x10, vcore at 1.50 volts; 40 hours orthos stable)

I had been running with older 533Mhz memory (from a prior machine) up until I got this new memory. I popped in the 8500s last night and set out to run some tests.

My first issue, and I've read about this before, is it comes up as DDR2-4300 when the memory settings are left on auto. I did adjust the vmem to 2.2 volts (and also tried 2.3 volts).

I tinkered with the Chipset page in the BIOS and set 5-5-5-12-? but there is a 5th number there that I don't know what to do with. I set it at 2 and it seemed okay... for a bit.. then I tried 4 b/c I saw some other post about using that setup. I see VERY FEW people actually mention this 5th setting but there is no way for me to put it on AUTO without putting all the timings on auto so I need to know what goes in there.

I tried various combos of auto settings on that SPD part as well as on the memory Mhz settings on the OC page in the bios.... I found a setup that 'worked' but it still showed on DDR2-4300 on boot and it just doesn't seem right...

Help please!

 

[n7]

You need to set the divider.

Default divider is 1:1, so of course it comes up as 4300 on the boot screen.

Go into the CPU Jumperfree Config section.

Dividers should be in there.
Using the 4:5 one would put your RAM @ 437.5, or the 2:3 one would give you 525 (DDR2-1050).

 

[jg0001]

So I do see a setting to make it DDR2-1050.. so I'd use 5-5-5-15-___ and also set the DDR2-1050 setting....
but what IS that last blank setting after the 5-5-5-15-???? Choices are 2-6 for that last item.

What voltage in the bios is good to use? For the P5W, should I set it at 2.2 volts (as standard), leave it on auto, set 2.3 volts maybe (if I assume the ASUS board undervolts it?)?

 

[jg0001]

BTW, the ASUS board doesn't give dividers per se, it just gives outright speed selections which I suppose just does the math for me.

Is it best to set both the SPD settings (i.e. under the chipset page on the bios, this is the 5-5-5 bit) or leave that on auto and just set the DDR2-____ speed instead?

 

[renozi]

well that last number is defaulted at 4 so lets try leaving it at that for now.
go to the corsair website to check on ur memory's timing and volts at certain speeds

http://www.corsairmemory.com/corsair/products/specs/TWIN2X2048-8500C5.pdf

looks like 5-5-5-15 @ 2.2v for 1066MHz

 

[jg0001]

I saw that. But what is the 2T on the end there? That 2 doesn't seem to be the 5th # I'm looking for.

Is what your suggesting that I leave it at 5-5-5-15-4 explicitly typed in and then toy around with the divider by selecting a speed rating on the other bios page?

 

[renozi]

yea thats right jg0001
it should run...i mean that is spec after all

 

[n7]

2T isn't usually listed, since all Intel mobos run 2T by default IIRC.

BTW, that 1050 speed you saw is the 2:3 divider, it's just that Asus kindly does the math for us

As for the timings after the 5-5-5-15, either go to XS forums (xtremesystems.org) & read up on those, or just leave them at whatever they are at by default.
BTW, don't be shocked if you have problems running the RAM stably with the 2:3 divider.
Sometimes mobos dislike that when heavily OCed.

You might want to experiment with lower multis + higher FSBs & the 4:5 divider instead of stock multi + 2:3 divider.

That's the whole fun of OCing