What is the Max safe IMC voltage for 24hr use?

[Clint_NZ]

Kia Ora from New Zealand.

This is probably posted somewhere else but I couldn't find a definite answer.

So what is the max safe voltage for my i5 750's Integrated Memory Controller for a continual overclock?(8hrs+ a day, lets call that 24hrs).
I think the absolute max rated by intel is 1.4v

On the side: Would this max safe voltage change for an i5-760 or i7-860. Probably not aye?

When I use the ram's XMP profile the IMC voltage is set to 1.35v and it's a purple warning colour!!

MOBO: P7P55D-EVO (LGA1156)
CPU: i5 750 @ 3349MHz (stock 2.67GHz)
COOLER: Cooler Master HyperX 212+ (MEAN AS COOLER for cheep)
RAM: Kingston HyperX DDR3 1600MHz (1600C8D3K2/4GX) @ 1340MHz 7-7-7-15 T1
GPU: HD5850
PSU: Enermax Liberty 650w modular
CASE: Antec 900 II
System drive: OCZ Vertex 3 60GB
Storage: 3 other HDD's

 

[Clint_NZ]

I just put everything to stock except i left DRAM voltage @ the rated 1.65v and I put IMC voltage to the lowest possible 1.1000v to try and test out that DRAM-IMC 0.5v delta problem that is with socket-1333. My delta is 0.55v and it doesn't seem to matter.

Next im gonna try getting the lowest latency's possible at DDR3 1066MHz then at DDR3 1333MHz
For some reason my system (not sure if it's ram, mobo, cpu or combination of everything) DOES NOT like it when I run my ram at the rated 1600 8-8-820. So I'm trying for mega low latency's at lower throughputs. Apparently low latency's are what benifits games the most anyway. But i am aware latency is a function of throughput * timings so I think 1600 8-8-8-20 is better than 1333 7-7-7-15. However I did see somewhere that DDR3 1066 CAS 5 kicked ass in games for the i7 920.

 

[Lutfij]

old thread but check this out: http://www.tomshardware.com/forum/295475-30-h67h2-bsod#t2006123

and this
http://www.tomshardware.com/forum/256105-29-overclocking-guide-under#t1832664 and continue reading to a few more posts : explains it.

hope this helps.

 

[Clint_NZ]

Cheers mate. I should have done more hunting but I wanted to make a real obvious title for others with the same questions to see.

The guy in the second forum said the absolute max IMC voltage is 1.21v though i'm not convinced. People say all sorts of different numbers. I was looking to find a hard limit from intel spec, which I think is 1.4v and also a safe max voltage for overclockers.

Ah well. I just wont stray into the red. On my board that happens above 1.3v IMC.

 

[Lutfij]

hmmm - for my Sandy Bridge build i stayed within 1.2

for the first gen i5's you should be on the borderline 1.3. Dunno where you got 1.4 but if your board is red at 1.3 than yeah, your board is wicked

Edit; yeah i noticed you have an Asus board - awesome for some reliable OC'ing!

 

[Clint_NZ]

Best answer selected by Clint_NZ.

 

[Clint_NZ]

Thanks heaps mate.

I'm convinced now. I've done some more reading and found another forum and the intel spec sheet:
http://forums.anandtech.com/showthread.php?t=332659

So the Lynnfield chips are spec'd to opperate up IMC = 1.155v

The absolute max is vcore = 1.400v and IMC = 1.21v. Thats for safe and continuous opperating

Apparently the IMC max voltage has since been updated to 1.4v, but that isn't recommended for long term use.
http://download.intel.com/design/processor/datashts/322164.pdf Table 7-4


There are people raving about with crazy 1.35 - 1.4 IMC voltages and high overclocks but I've concluded it's best not to go there with IMC.

I have noticed Asus boards overvolt everything when using automatic profiles or even XMP profile in my case. It sets IMC to 1.3v for a simple DDR3-1600 8-8-8-20 (which has never been stable). Aside from that, I agree. Asus boards are awesome for stable overclocking and personally they have the most intuitive bios. I attempted to use a mates gigabit board but the overclocking options were scattered all over the place and nothing was very clear. I am sad that I splashed out a little on the EVO model, which is awesome, just to get my socket outdated by 1 freeking pin with the sandy bridge cpu's. And who's betting that Ivy bridge is going to have yet another socket!?

 

[Lutfij]

I have noticed Asus boards overvolt everything when using automatic profiles or even XMP profile

i dunno about my Maximus III Formula(since i didn't OC it yet) - but my Rampage Extreme x48, does overvolt stuff - even with ram dimms while OC'ing on auto settings via BIOS.

well - from the looks of this: http://event.asus.com/2011/mb/PCIe3_Ready/ these sandy bridge mobo's can support ivy bridge and for the first time in a long time they aren't phasing out the 1155 socket...or so they have us believing.

* your welcome, mate - we're here to help!