1333 FSB & DDR2 PC8500 Question

[Indi75]

Ok, I'm gonna ask a completely dumb question in the eyes of some, but since I want an answer I'll take the chance that this place is relatively bereft of smart-ass mongs waiting to ridicule me.

I've just agreed to offload my current build for about £700 quid as fancy a refresh and simply upgrading the E6600 was never really gonna be that exciting.

I'm just concerned that the E6850 certainly has Mobo's to choose from at 1333 but very few DDR3 sticks. Infact about 2 from Corsair.

I'm sure I can, but would some explain how to use DDR2 PC6400 or DDR2 PC8500 with FSB of 800/1066 respectively on a P35DDR2 board with a CPU running at 1333?

Is it all in the ratio? For example I currently have DDR2 PC6400 running at 800 on an E6600 running at 1066. Can I assume that buying some 1066 Dominator will work the same way with the E6850?

Some light shedding would be greatly appreciated.

[staffsMike]

read clunks overclocking guide.. that will help.

Essentially DDR2 memory's FSB is multiplied by two so when you say its running 800mhz.. its actually running 400mhz... x2 and the CPU is multiplied by 4 so when you says its running 1066 is actually running at 266mhz .. x4


If you running a 1:1 ratio the only way to run the ram at 800mhz is when the e6600 is clocked to 3.6Ghz

[GSte]

Yes, it's all in the ratio.

Take RAM's rated speed and divide by 2 to give actual speed. Take CPU's rated fsb speed and divide by 4 to give actual speed.

You can set a memory divider in your BIOS depending on what speed you want to run the CPU and RAM at. For example, CPU with 1333fsb actually runs at 333MHz. Ram with DDR667 rating actually runs at 333MHz. These would then run at stock speeds in a 1:1 ratio. If you wanted to use a 1333fsb CPU with DDR800 ram, you would have to use a 4:5 divider (or ratio), which would have your ram running slightly overclocked at 416MHz actual (or DDR832). Any clearer or have I just confused things?

[Indi75]

No, not confused things, helped tremendously, thank you both.

Can I therefore ask which P5K Mobo I would buy that will support the E6850@1333 along with DDR2-PC8500@1066+ or DDR2-PC6400@800+ ('+' obviously allowing for the slight overclock of the RAM through the divider)

I presume I avoid the Asus P5K3 Deluxe/WiFi-AP as this is for DDR3 only, and must buy a Asus P5K Deluxe/WiFi-AP for DDR2?

[Agent]

Ok, I'm gonna ask a completely dumb question in the eyes of some.....

Buddy, the only 'dumb' question is the one that isn't asked

All levels are welcome here

[GSte]

No, not confused things, helped tremendously, thank you both.

Can I therefore ask which P5K Mobo I would buy that will support the E6850@1333 along with DDR2-PC8500@1066+ or DDR2-PC6400@800+ ('+' obviously allowing for the slight overclock of the RAM through the divider)

I presume I avoid the Asus P5K3 Deluxe/WiFi-AP as this is for DDR3 only, and must buy a Asus P5K Deluxe/WiFi-AP for DDR2?

Aye, that's right. Clunk has a good P5K Deluxe overclocking thread on here if you're interested.

[Indi75]

Reading it now with interest. Thanks.

[Indi75]

Looking like I'm gonna go with http://www.scan.co.uk/Products/Produ...oductID=585716.

There's no point me buying Vista Ultimate 32bit now and hen changing it to 64bit later, and the 4GB is more than welcome.