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Turbo Boost Core i5 how does it work?

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Firestrider

Member
Joined
Dec 9, 2003
Location
Orlando, FL
  • Theoretically could any motherboard that supports a 95W TDP processor allow for optimal usage of turbo boost?
  • Turbo boost only increases the clock speed if it is in the thermal and power envelope of the processor correct?
  • Therefore, would turbo boost depend on the heatsink of the CPU and nothing else?
 
Turbo boost is not just affected by cooling. You could have great temps with a semi high v-core and can deactive it if the system goes out of the super secret specs.
 
Intel published a small whitepaper that contains hardly any low-level details but plenty of lay PR words describing Turbo Boost. It satisfies most: http://www.intel.com/technology/turboboost/

According to Intel, the PCU within the Uncore monitors and regulates the Core area of the Nehalem die so when the overall temperature of the die and the estimated current draw is below the rated maximum, the PCU overclocks the Core area as much as it can while trying to remain below the maximum rated temperature, current and power.
 
Thanks for the response KTE.

I'm just wondering if a budget motherboard that supports a Core i5 (95W) is able to provide the current and wattage needed during Turbo Boost. Would there be any limitation of the electrical components around the CPU?

I want a budget build and don't plan to overclock but I want Turbo Boost to work optimally... that is 4 speed bins with one or two cores and 1 speed bin with three or four cores on an i5 750.
 
Yes, you should be fine for Turbo. The only issue is that most board manufacturers don't build the boards to work exactly within Intel specifications. Core 1 should increase two multipliers when everything is within specs and the other three are idle. When one of the idle cores does anything at all, core 1 falls back one. It seems like most boards just leave core 1 at 21x from what I have read.

Budget or not, not overclocking should be well within specs for turbo.
 
I don't know the full details, Intel won't say anywhere to anyone (and I mean biggest reviewers here). Question anything todo with power/temps in detail, they always avoid and run.

What I do know is 89A is the stock Core area limit. Even decent 3-phase solutions can provide that. Uncore is not supplied by 12v so you don't need to worry.

In terms of power, Lynnfield doesn't draw 89A at stock, not until TB kicks in so you should be fine as long as your temps are right and as long as the voltages aren't going too high (MB MFGs always mess this aspect up).

TB is an excellent concept. The only problem I have with it is, it increases voltage highly unnecessarily thereby limiting itself. If you customize TB frequency and voltage, it will work out much better, meaning, you should be able to gain max TB clocks on all Cores even after some undervolting (so you'll always be under 89A and hence always work at max clocks).
 
If you don't plan to OC...any board will be fine...just shop based on features for your requirements/preferences.
 
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