In theory, yes. In practice, 200x20 with RAM at 1600 can often be unstable for no obvious reason. The explanation is here.
With uncore at 3.2 and QPI at 3.6 (7200) you should be fine.
With uncore at 3.2 and QPI at 3.6 (7200) you should be fine.
i7 Overclocking theory.
2
I've done a bit of research, but I want to be 100% sure I know my stuff before I go tweaking things and destroy my baby...
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So, to my understanding the basic information for the i7-920 goes as follows...
Multipliers:
Core - x20 (X21 in Turbo)
Uncore - x16 (must be twice ram, 8:9 to QPI preferred... the closer to 1:1, the more unstable)
QPI - x18 (locked on some boards???)
Memory - x8 (Locked on some boards???)
Voltages:
Core - 1.2v stock, 1.375 max allowable under spec
Uncore - (Don't know stock, must be within .5v of memory)
QPI - 1.1v stock, some claim it should match core, but I'm not sure why
Memory - 1.65v theoretical maximum due to potential harm to cpu, but generally it's considered safe at 1.66v (must be within .5v of Uncore)
Stock Freqencies:
Stock Bclk = 133.
Stock Core = 2.66
Stock UnCore = 2.13ish
Stock QPI = 2.4Ghz (4.8GT/s)
Stock Memory = 1066
To reach the 4.0Ghz goal (with ram at rated speed of 1600) the following would be true:
===EDIT==This may be unstable due to the ratio between the Uncore and QPI===
Bclk = 200
Core = 4.0 (x20)
Uncore = 3.2 (x16)
QPI = 3.6 (7.2GT/s) (x18)
Mem = 1600 (x8)
Safe settings:
Bclk = 200
Core = 4.0 (x20)
Uncore = 2.4 (x12)
QPI = 3.6 (7.2GT/s) (x18)
Mem = 1200 (x6)
If ANY of this is even remotely incorrect, PLEASE correct me and explain why.
![]()
So, to my understanding the basic information for the i7-920 goes as follows...
Multipliers:
Core - x20 (X21 in Turbo)
Uncore - x16 (must be twice ram, 8:9 to QPI preferred... the closer to 1:1, the more unstable)
QPI - x18 (locked on some boards???)
Memory - x8 (Locked on some boards???)
Voltages:
Core - 1.2v stock, 1.375 max allowable under spec
Uncore - (Don't know stock, must be within .5v of memory)
QPI - 1.1v stock, some claim it should match core, but I'm not sure why
Memory - 1.65v theoretical maximum due to potential harm to cpu, but generally it's considered safe at 1.66v (must be within .5v of Uncore)
Stock Freqencies:
Stock Bclk = 133.
Stock Core = 2.66
Stock UnCore = 2.13ish
Stock QPI = 2.4Ghz (4.8GT/s)
Stock Memory = 1066
To reach the 4.0Ghz goal (with ram at rated speed of 1600) the following would be true:
===EDIT==This may be unstable due to the ratio between the Uncore and QPI===
Bclk = 200
Core = 4.0 (x20)
Uncore = 3.2 (x16)
QPI = 3.6 (7.2GT/s) (x18)
Mem = 1600 (x8)
Safe settings:
Bclk = 200
Core = 4.0 (x20)
Uncore = 2.4 (x12)
QPI = 3.6 (7.2GT/s) (x18)
Mem = 1200 (x6)
If ANY of this is even remotely incorrect, PLEASE correct me and explain why.
1 - 16 of 16 Posts
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Quote:
Ah ha, I should probably keep that in mind.
Is there a thread with all this information consolidated? If not, maybe we should start one.
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(and is there anything else I'm missing?)
Originally Posted by error10 Right. at 4.8GT/s the QPI is running at 2.4GHz. (This is why some boards will show a 18x multi and others will show a 36x multi.) |
Is there a thread with all this information consolidated? If not, maybe we should start one.
(and is there anything else I'm missing?)
Quote:
Is that uncore voltage to Memory voltage?
Originally Posted by Autox don't forget, qpi/vtt volts have to be within .5 of vdimm |
Quote:
i think he's referring to LGA1156 boards.
Originally Posted by 88EVGAFTW What mobo do you have that locks the QPI and Ram? Mine does not have anything locked and my QPI runs at X18 and will go all the way to X24. http://www.madshrimps.be/vbulletin/f...04/#post242642 |
1 - 16 of 16 Posts
