C1e and EIST

I have a desktop system with the core-2 duo e6600 as my cpu. Initially, I was using C1e (enhanced halt state) only. Now, I'm using both C1e and Speedstep (EIST). I understand that both of these lower the voltage and clock cycle of the cpu to conserve power and reduce CPU temperature.

When I first purchased the computer from Dell, EIST was "off" by default in BIOS, but I activated EIST by turning it 'on" in BIOS and then changing my power scheme in the OS to "portable/laptop"

My question: Is there any advantage (or disadvantage) to using BOTH C1e and EIST? Performance-wise, I don't see any difference in using one or both. The only difference I detect is that using C1e alone runs the cpu with either a 6X or 9X multiplier while EIST has additional multipliers of 7X and 8X.

Thanks for any info.

 

Might be off topic a bit but just setting up a new system and wondering why my CPU speed was fluctuating between 1.995 and 2.33G ... it was because C1E was enabled in the BIOS ... not now

 

It's advantageous to have C1e and/or EIST "on". This will save power and keep your CPU cooler. It doesn't really affect performance because your CPU will automatically throttle up to the highest speed when you need it, for example, when you're playing a game. For most applications (web-surfing, e-mail etc.) there is no peformance advantage to having your CPU running at top speed, for the reasons mentioned above.

Bob

 

Cool and will check it out Bob I was a bit alarmed at the changes as I just finished putting this system together. Actually going to post up some results on Graysky's X264 and X264HD tests and will try them with C1E enabled.

Cheers on the info

PPS:I googled earlier for E6550 CPU frequency fluctuations and came across a post mentioning C1E causing this. Thats why I changed it.

 

Might be will see THX on the info guys

http://forums.techarp.com/reviews-articles/23065-x264-benchmark-10.html#post325581