Some basic questions about Core2 cpus and FSBs.

[cokebottles]

Sorry if this stuff is well basic, but I have been 'out of the game' for quite some time, and am wondering as to how things have changed.....

Right... I am looking to build a HTPC around the Antec Fusion chassic (430w psu) and Abit Fatal1ty mATX hdmi equipped motherboard. The motherboard is rated to support FSBs up to 1066mHz. Due to budget constraints, my DDR2 modules are more likely to be of the 800mHz variety..... and the Intel Core2Duo cpus I have been looking at, have a number of different FSB speeds, and was looking to enquire as to how compatible these all are with each other.

One scenario is: 1066mHz motherboard, 800mHz DDR2, and the E6550 1333mHz cpu.

I clearly wouldn't be running at 1333mHz fsb, so would the motherboard and cpu support a higher multiplier, so I could still run the chip at it's stock speed, or with the E6550 and 800mHz ram, would I be looking at running the cpu at a lower clock speed????

 

[Posty]

I don't think a CPU with 1333 fsb would work in a motherboard that supports 1066

I would get this
http://www.overclockers.co.uk/showproduct.php?prodid=CP-145-IN&groupid=701&catid=6&subcat=793
http://www.overclockers.co.uk/showproduct.php?prodid=MY-088-CR&groupid=701&catid=8&subcat=144

Just so you know C2d are quad pumped so take the "fsb" and divide by 4, in your example that would make it 333mhz
For DDR2 you just take the mhz and divide by 2 so in your example that would be 400

C2D with 1066 fsb is 266
C2D with 1333 fsb is 333

PC4200 is 266
PC5300 is 333
PC6400 is 400
PC8500 is 533

 

[SideWinder]

Just to be certain then...

Intel® 975X Express Chipset

+

QX6850

=

Won't work?

 

[stoofa]

You'll need to check the manufacturers website for BIOS updates and a list of the supported CPU's.
You can't say that no 975x based board will work with a QX6850

 

[SideWinder]

Okay, i'll take a look - thanks.

 

[enigmo]

Have you already bought all this hardware or is this just options so far? If you already have the mobo and case, why not just get a 1066MHz bus chip?

 

[zammo]

C2D with 1066 fsb is 266
C2D with 1333 fsb is 333

PC4200 is 266
PC5300 is 333
PC6400 is 400
PC8500 is 533

so, does that mean that pc4200 ram would work better than pc8500 ram with a C2D with 1066 FSB?

 

[helmutcheese]

You get faster ram it gives more head room to OC and you can run the FSB in sync with Ram 1:1 some have mad high clocks like 1333 FSB/RAM 1:1 in the comments section of the CPU/MOBO/RAM in the store.

 

[zammo]

You get faster ram it gives more head room to OC and you can run the FSB in sync with Ram 1:1 some have mad high clocks like 1333 FSB/RAM 1:1 in the comments section of the CPU/MOBO/RAM in the store.

So if you weren't overclocking a C2D 1033, then there is no advantage in pc8500 over pc4200?

 

[helmutcheese]

Probably not, but most will buy PC6400 anyhow.

 

[zammo]

Probably not, but most will buy PC6400 anyhow.

cheers for that, you've probs just saved me £100 without giving me the niggling thought in the back of my head that I could have bought better