PC6400 @ 333mhz not 400..

[streetster]

Hey Guys,

Just built a new c2d system for someone, with an E6600 in there and an Asus P5W Deluxe motherboard... Put in 2x1024mb of Corsair XMS-somethingy-6400 stuff... but cpu-z says its running at 333mhz (ie 667 ddr, rather than rated 800mhz ddr).

I had a look through the bios but the only option available in terms of memory control (that i could see) was adjusting the cas/ras/etc values, and not the memory divider...

anything I can do?

[badass]

Hey Guys,

Just built a new c2d system for someone, with an E6600 in there and an Asus P5W Deluxe motherboard... Put in 2x1024mb of Corsair XMS-somethingy-6400 stuff... but cpu-z says its running at 333mhz (ie 667 ddr, rather than rated 800mhz ddr).

I had a look through the bios but the only option available in terms of memory control (that i could see) was adjusting the cas/ras/etc values, and not the memory divider...

anything I can do?

Some motherboards have a shortcut key you have to press to show the advanced options. You might find a memory divider in there possibly.

[Clunk]

Default would be 533.

You can set the memory to run faster with the dividers, but you can often experience instability. If you overclock by raising the fsb, the memory speed will rise as well.

[streetster]

Default would be 533.

You can set the memory to run faster with the dividers, but you can often experience instability. If you overclock by raising the fsb, the memory speed will rise as well.

default would be 533? but its only 400mhz ram...

I'll have a google to see if there is an advanced menu somewhere around there... cheers

[dave87]

technically its 200mhz ram, but with DDR2 the data is transfered on the rising and falling edge of each cycle, so is doubled to 400mhz, then because its Double Pumped, it becomes 800

The E6600 has a fsb of 333, which doubled is 667, so you'd need to overclock or set a divider to unleash the true potential of the RAM.

Thats how I've always understood it...

[kalniel]

The CPU clock for an E6*00 system is 266mhz, that means the FSB is 1066 and you use DDR2 533 ram at 1:1.

At 4:5 the CPU clock and FSB are still 266 and 1066, but now you're using 333mhz ram (DDR2 667).

To get to 400mhz ram, you either need a 2:3 ratio selection or to overclock your CPU clock to 320mhz.

AFAIK, asus bios' select ratio by selecting memory 'speed', thus to select 4:5 ratio you pick 667, and to get 2:3 you pick 800.

[streetster]

there was some 'AI Overclock' option which was set to AUTO... i set it to 'manual' and a whole host of options (ie fsb/multiplier/etc that im used to) appeared. I chose 800mhz for the memory, and voila it worked fine.

cheers guys

[dave87]

The CPU clock for an E6*00 system is 266mhz, that means the FSB is 1066 and you use DDR2 533 ram at 1:1.

At 4:5 the CPU clock and FSB are still 266 and 1066, but now you're using 333mhz ram (DDR2 667).

To get to 400mhz ram, you either need a 2:3 ratio selection or to overclock your CPU clock to 320mhz.

AFAIK, asus bios' select ratio by selecting memory 'speed', thus to select 4:5 ratio you pick 667, and to get 2:3 you pick 800.

Yup, thats right (sorry more experience with AMD based systems than Intel ones atm )