MIR overcloking test?

[Sapkiller]

 Dear Vienna ( CM )

I seem to remember that you ran some tests using a dual E5520 overclocked to 2.9 Ghz - how did that come along?

I am a bit reluctant to cach out a whole lot of money on W5580's and plan to use a less expensive XEON - mayby a E5530 or X5550 and then overclock it a little bit to make up partly for the CPU performance, but also to get the memory bus up from 1066 to 1333 when using 6 RAM modules ( if it actually works this way with the Nephalem? ).

eg. to get from 1066 to 1333 a factor of approx. 1.25 is needed, using the same factor on a E5530 nominal speed 2.4GHz,  you get 3 GHz - which is comparable to  X5570. 

Does this make sense?

[Sapkiller]

 Bump

[Sapkiller]

Dear Vienna

Don't you have some input for this?

[Dietz]

Uhm - sorry, Bjarne, I didn't miss your message. It's just that all our local IT-gurus seem to be extremely busy these days (... and I'm just an audio-guy :-) ...) Thanks for your patience!

[Sapkiller]

oh - I understand all about being busy, so no worries.

I´ll just wait until Christian gets more freetime.

[cm]

the nehalem processors (i7, XEON 55xx) are able to increase processor frequency for 2 133 MHz steps if the temperature allows and the CPU load requires (has to be enabled in the computer's BIOS) - that's called turbo boost technology.

memory bus frequency always depends on the processor model and number of memory modules per channel and does not increase with the processor speed.

 

eg. the E5520 has always a memory bus speed of 1066 and allows overclocking to 2.26 GHz + 2 x 133 MHz = 2.53 GHz

the 5550 has 1333 MHz memory bus speed with 1 and 1066 with 2 memory modules per channel

hth, christian

[Sapkiller]

Hi Christian

So as I understand it is not possible increase memory speed - they are fixed at the clock rates depending on the number of channels used?

That sort of leaves my plan in ruin....

a better plan then would be to use a X5550 and then step it up if need be.

thanxalot for taking the time to answer

[cm]

correct - and it makes perfect sense ....

compare to the rpm meter of your car, at say 7.000 rpm the red area begins. you could run your engine at 8000 rpm for a while using expensive oil and good cooling, but at some point the engine will overheat, crash  and die.

on former motherboards you could overclock a processor in a perfect system and everything increased with CPU frequency (FSB, memory speed, PCI bus sppeed) - this is no longer doable in the range of 1066/1333 MHz, you would get too many memory errors.

 

intel specification for the on-processor memory controller (which has 3 channels per controller):

1 module per channel: max 1333, 2 per channel max 1066, 3 per channel max 800 - correlates with the overall data throughput and bus timing.

christian

 

ps: to add some confusion - the new i5 processors and the i7 800 family has only 2 channels per controller

[Sapkiller]

thx - just curious: Since the memory bus is fixed, can you actually run with 2 different 55*, with seperate clocking on the same dual socket board?

[cm]

all dual processor socket machines always need to be equiped with the same processor model, actually with same model and same stepping (eg. with the 5520 there is a C0 and a D0 stepping) - that's as it has ever been ;-)