Overclocking+EIST+C-States+Dynamic Vcore

[Pink_Waters]

...
it failed to post with multiple rapid beeps! :x

yeah, you should laugh, you've got Intel i5-750 @3.8GHz @1.225v !

Update..
Now I've came across a weird issue, and from the searches I made around forums, its pretty common with certain hardware configurations..

I noticed with C1e and EIST on, that my PSU makes crackling noises with hdd activity and when scrolling pages in IE... also I was able to reproduce that when opening steam and just moving the mouse cursor around its interface...

I opened CPUID hardware monitor and CPU-Z, and I noticed that either scrolling pages in IE or moving the mouse on steam interface, disables the EIST and moves the multiplier to 20x making a full load with full CPU Amps and Watts!! beside the crackling noise of course!
aslo I am getting the PSU whining a little while in game screens!..
PERFECT !!...

 

[humph]

Bzzzz. Yeah, that seems to be the "downside" of not using fixed volts.
I'm just guessing/hoping that it's normal due to the PWM switching frequencies being in audible range, and so the PSU's are not suffering - well, you'd expect them to be OK, since this is normal operation, and many people get the same noise, seemingly with different vendor PSUs and not el-cheapo ones either.

More "worryingly" I noted that I hear a single loud "click" from deep inside the case when booting XP, at the point when the XP boot banner changes to desktop (approx). I'm not sure I heard it before I started to play with overclocks....and I'm not overclocking the GPU. Not managed to figure out if its from the PSU or the Graphics Card. I think it's also now there when I set everything back to stock (can't remember 100% offhand). Ho Hum...

 

[Pink_Waters]

if you can get a stethoscope you can trace the noise better...
the noise I am getting from the psu, seems more like a screeching. though..
but scrolling a page in IE brings the cpu multiplier to 20x really ?! its like EIST is not working as it should!

the shocking news that I am having a hard time to swallow is this:

yesterday I tried to test and see how things would be going @3.4ghz
I played with a different combinations of multipliers and bclks, and set the vcore and vtt to standard, and I was unable to post! getting rapid beeps...

so I played again with multipliers till I got the ram @1600 (rated) and CPU clock @3.4...no dice!

so I ultimately raised vcore to 1.3v and raised vtt to 1.2v and saved, and tried booting,...
I WAS UNABLE TO POST!! GETTING RAPID BEEPS!

That seems unusual! whats up with that ?!

 

[humph]

if you can get a stethoscope you can trace the noise better...
the noise I am getting from the psu, seems more like a screeching. though..
but scrolling a page in IE brings the cpu multiplier to 20x really ?! its like EIST is not working as it should!

Well, I guess OSX is set to provide as fast a UI as possible. Why idle the CPU when you can get extra performance for slick and fast user interface experience?
Yeah, screech is a better word than buzz, I concur. Also get that screech when for example doing a rapid scroll of the album art in iTunes (can get a really fast scroll with Magic Mouse swipe gersture!).

the shocking news that I am having a hard time to swallow is this:

yesterday I tried to test and see how things would be going @3.4ghz
I played with a different combinations of multipliers and bclks, and set the vcore and vtt to standard, and I was unable to post! getting rapid beeps...

so I played again with multipliers till I got the ram @1600 (rated) and CPU clock @3.4...no dice!

so I ultimately raised vcore to 1.3v and raised vtt to 1.2v and saved, and tried booting,...
I WAS UNABLE TO POST!! GETTING RAPID BEEPS!

That seems unusual! whats up with that ?!

Don't really have any good ideas on that. But since there's some limitation - perhaps you have a "overclock-unfriendly" CPU - it might be time to "work up" (if you were not doing it this way) along the lines of the article at:
http://www.overclockers.com/3-step-guide-overclock-core-i3-i5-i7/
To establish max BCLK, memory then CPU settings for given volts.

 

[Pink_Waters]

Figured the culprit.. its the Ram!!

it won't run @rated specs with 170bclk

I am now running it on 8x multi with timings set to auto, which lowers it to 1360mhz 9-9-9-24
why is that?! it runs fine on 160bclk @rated speed!
also I tried 200bclk to get me 3.4ghz with ram @1600 setting timings @auto but got crashes and BSOD alot, but maybe thats because 200bclk could be hard to aim for and its unstable on me or maybe because of c1e/eist/c-states ... will do some digging on that..

So, I went ahead and turned down ram voltage to 1.5v since iam running it @low clock/timing
so I am running now fine 3.4ghz with vcore @normal, and VTT @normal.. with c1e and EIST and c-states enabled...

but donno if 1600 @7-8-7-24 differ much from 1360 @9-9-9-24

 

[humph]

but donno if 1600 @7-8-7-24 differ much from 1360 @9-9-9-24

Well, on paper, that's a lot slower at 1360, although whether it makes much difference to day-to-day tasks sort of depends on what you're doing and whether RAM is a bottleneck in those apps/operations.
I guess you can see what sort of impact it has on benchmarks, eg: RAM parts of GeekBench.

Although, you ought to be able to tighten up (manually) the timings a bit (although perhaps less so @ 1.5V) if running at 1360MHz.

But hey, nice progress to get to 3.4GHz!!

 

[Pink_Waters]

Update...

I tried running the ram @1360 @1.5v at those timings and things seems pretty stable:

7-7-7-20 1T

I don't know, but those seems pretty damn good timings @ that clock speed/voltage

 

[humph]

Yeah, I can only wish to get those on my chips! Am traveling so unfortunately can not experiment with my stuff at the mo.

On other hand, since your's were rated 7-8-7-24 or whatever @1600MHz, you'd be really unlucky if not able to maintain 7-7-7 at the slower 1333MHz. Getting to 6-6-6-18/20 or 6-7-6-19/20 would be real nice. (1333/1600*7=5.8...so ought to get 6; but whether that can be achieved at 1.5V would be the question!).

 

[Pink_Waters]

yeah, @1.5 would be the question
well, I doubt it though...

safe trip dude

 

[sch8mid]

Luckily got a nice i 7 750 chip with a good batch that boots in Win7 @ 4,52 on air @1,34 V load and finishes a 32 M SuperPi in 8.06 .(inst. with iboot-ati5x)

Boots in OSX 10.6.4 @ 4,45 . Not for 24/7, though temps are < 75 degrees C load.
Using an Armageddon cooler in pushpull config. with 2 14cm silent noiseblocker fans @ 900 RPM.

Geekbench : 14664 @ 4,2 GHz

Case is a Lian Li with one 14 cm fan blowing in @ 900 rpm and one 14 cm out (same speed) controlled by an akasa fan control.

I threw out the HD cages to get the right airflow and used the 5,25 slots for my 3 HDs.

24/7 in OSX is 3,6 Ghz with all CPU , Turbo , C states enabled . RAM @ 1600 6-8-6-20
Vcore : 1,28 V minus DVID - 0,14 results in 0,82 V idle , 1,18V load -vdrop = intel specs.
Temps @ 800 RPM : 43 idle/64 load (Linx) @1200 RPM : 40 idle /60 load (Linx-25 runs)

At 24/7 config. got a Geekbench of 13300 , Cinebech > 40 fr. in OpenGL , < 7sek. in OpenCL , using a stock HD 5770 .

Overall I am quite happy with this rig.
If by chance you use an HD 5770..
You may look at my OpenGl database to control if your rig is working well.

http://www.insanelymac.com/forum/index.php?s=&showtopic=205802&view=findpost&p=1554521

best
a
Some OC results (HD 5770) here:

Number 1 score in Cinebench Win 7 and MacOs X :
Number 1 score in OpenCL OSx 10.6.4

Geekbench :14664 @4,2............13300@3,6

Cinebench 11.5: >45 fr. @4,2........>40fr.@3,6

OpenCL : Midrange : 6,8 sec. ..Sponza Ultra 35,3 sec.




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