Difference between a 1333 fsb cpu on a 1333 fsb mobo and a 1066 fsb mobo

[BloodTotal]

basically what would be the differnce between a cpu like an e8500 running on a p5b mobo, and running on a p5q mobo??

thanks, if my post needs more clarification tell me

 

[erocker]

The 1066 motherboard would need to be overclocked to 1333 to run the chip at stock.

 

[lemonadesoda]

simply; the multiplier.

cpus dont run at a fixed speed - they run at a multiple of the bus clock they are fed

 

[Error 404]

I don't think a CPU with a 1333 MHz FSB would run on a 1066 MHz FSB supporting motherboard anyway, unless it specifically said so in a CPU compatibility list (which should be accesible at the motherboard maker's website).
For example, the motherboard in my second PC can't run any CPU with a FSB higher than 1066 MHz, because that is what the max FSB speed on the motherboard is.
Most of the original 65nm Core 2 Duo supporting motherboards wont support the newer 45nm C2D CPUs, unless there is a BIOS update that will work with them.

 

[erocker]

Sure it will run. It just won't run it at 1333 fsb and yes it does need be compatable. It can be compatable and still be a 1066 mobo.

 

[Error 404]

Sure it will run. It just won't run it at 1333 fsb and yes it does need be compatable. It can be compatable and still be a 1066 mobo.

That is true, but it must be compatible, otherwise it wont run at all.

 

[3870x2]

I think its like ram: it will underclock to the specification.

 

[BloodTotal]

so overclocking a 1333 chip on a 1066 would be crap correct?

 

[Kursah]

For 1333FSB you'd need 333 system FSB set in bios, 1066 is 266, etc. Many know this, but when you look at it that way, it's not that big of a deal. If the mobo in question does not support 1333FSB via stock standards, many will be able to hit that standard via OC. Some MB mfg's were nice enough to include said compatability in a simple bios update, some have ignored the spec, just depends on what you have.

The difference between a P965 based P5B series and a P45 based P5Q series probably won't be too insane, I've had the Deluxe verisons of both, for me the P5Q Dlx has been the more stable board, but both were great OC-er's, both reaching 500FSB which would be 2000FSB by Intel's specs. But really I can't imagine any huge differences in overall performance, maybe some difference in memory bandwidth and latency, but even that would be minor I would imagine.

 

[Error 404]

so overclocking a 1333 chip on a 1066 would be crap correct?

Probably. You'd be better off getting a full speed motherboard, as the 1333 MHz motherboards usually support overclocking up to a 1600 MHz FSB, and maybe even further if you push it. Also, P45 is a more advanced chipset compared to the P965, so you might get a slight performance increase with it.

 

[Pinchy]

Well...

I have my e8500 in both a P5Q-e and P5B Dlx (currently using in the P5B dlx).

Has no probs hitting 4GHz on the P5b, havent tried pushing it further.

On the P5Q, I have hit 4.5-4.75GHz stable, but as I said, havent tried on the P5b yet.

 

[BloodTotal]

so what exact performance boost would happen going from a p35 to a p45 *specifically for the CPU*

it would run 1333 natively, but would it overclock better?

 

[BloodTotal]

Well...

I have my e8500 in both a P5Q-e and P5B Dlx (currently using in the P5B dlx).

Has no probs hitting 4GHz on the P5b, havent tried pushing it further.

On the P5Q, I have hit 4.5-4.75GHz stable, but as I said, havent tried on the P5b yet.

very good to know, big thanks