C1e and EIST

BobKaye · 21st Mar 2008, 03:45 AM

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.

Chai · 21st Mar 2008, 07:42 AM

There's really not much difference between C1E and EIST from my experience. EIST requires software support (changing power scheme in OS), while C1E doesn't. I tried enabling both too.

Mac Daddy · 22nd Mar 2008, 05:09 AM

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

BobKaye · 22nd Mar 2008, 05:42 AM

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

Mac Daddy · 22nd Mar 2008, 06:54 AM

Quote:

Originally Posted by BobKaye

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.

Chai · 22nd Mar 2008, 07:52 AM

Quote:

Originally Posted by BobKaye

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

It might be a problem if you are overclocking.

Mac Daddy · 22nd Mar 2008, 08:35 AM

Might be will see THX on the info guys

x264 Benchmark

21st Mar 2008, 03:45 AM	#1 (permalink)
BobKaye Newbie Join Date: 21 Mar 2008 Posts: 2 Reputation: 0 Rep Power: 0	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.

21st Mar 2008, 07:42 AM	#2 (permalink)
Chai Administrator Join Date: 6 Oct 2002 Location: Maranello Posts: 26,125 Reputation: 3845 Rep Power: 70	There's really not much difference between C1E and EIST from my experience. EIST requires software support (changing power scheme in OS), while C1E doesn't. I tried enabling both too. __________________ Chai (Contributor & Forum Admin) http://www.techarp.com/

22nd Mar 2008, 05:09 AM	#3 (permalink)
Mac Daddy Pickin' Da Gitfiddle Join Date: 19 Nov 2007 Location: Canada Posts: 2,048 Reputation: 802 Rep Power: 11	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

22nd Mar 2008, 05:42 AM	#4 (permalink)
BobKaye Newbie Join Date: 21 Mar 2008 Posts: 2 Reputation: 0 Rep Power: 0	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

22nd Mar 2008, 08:35 AM	#7 (permalink)
Mac Daddy Pickin' Da Gitfiddle Join Date: 19 Nov 2007 Location: Canada Posts: 2,048 Reputation: 802 Rep Power: 11	Might be will see THX on the info guys x264 Benchmark