Quote Originally Posted by dejanh View Post
Can you please explain what you mean by VTT/VDIMM ratio? I keep hearing about this from you and cstkl1 but there is no clear explanation to what this means. I managed to get Prime stable Uncore of about 4.3GHz on water but I do not remember identifying any VTT/VDIMM ratios along the way...ATM I am running ~4.1GHz Uncore as it seems to be a good balance between speed and voltages required.

On a different note, did anyone test the new S22A BIOS for the Classified E759? I tried it and it completely breaks my S3 which has been working perfectly for many many months now. Had to go back to S227 for ability to S3.
Quote Originally Posted by SAE View Post
There's a silent consent about vtt-vdimm ratio IMHO... i hear it alot in German forums. Truth is, there's an optimal distance between vdimm an vtt voltages, and it's to be kept for maintaining stability, speed and reliability of the memory system. Getting out of range too much either + or - results in bsods of 124 type, spontaneous reboots or plain instability.

My experiences have shown, that a difference between 200 and 240mV is optimal for my set of hypers and this 759 plus xeon cpu.


224mV^^


234mV^^

Vdimm has to be raised, even if there's no need to according to the great elpidas. That's just because vtt has to be increased exponentially - it seems - to maintain stability at high uncore clocks (1.324Vtt 4000 UC -> 1.46Vtt 4200 UC). You have to test it for yourself as hardware differs. Each board and set of ram is different, but you can take those values as a hint for what to try first. RTLs are directly coupled to this as well and have to be set up properly not to get hiccoughs.

Cheers,
Stefan. :cheers:

I'm real real new to i7. I'm currently reading and reading every chance i get to learn the technology. This is a noob question but how does uncore effect performance? Where would i see an advantage, real life or benchmarks, between say 3600 uc and 4200 uc? Thanks for answering a stupid question. And if somebody has a link to a real good informative, lamens i7 read, please post it for me. Thank You!