intel turbo boost question

so ive got the new AW17 with an i7 4800 and im having some trouble understanding turbo boost and what it actually does. I know my base clock is 2.7GHz and it turbos up to 3.7GHz. my question is why when im not doing anything cpu intensive my cpu sits around 3.5-3.99GHz, but the second I launch prime95 it drops right to 2.7GHz. should it not be the other way around? ive noticed in BF4 my cpu sits at 3.5GHz. max temps always below 90 so I don't think throttling is the issue here. just looking to see if this is right or if my cpu has issues? is there anyway to force turbo boost on at all times? ive been playing around with intel XTU and managed to set my multipliers to 41,40,39,39 which keeps all cores at 3.99GHz when im not doing anything but like I said as soon as I run prime9 it drops right down to 2.7GHz. Im just curious as to how turbo boost works and what the point of it is if it cant maintain that clock when under stress. also after about 5 minutes of prime95 my max temps are still within reason at under 90. you can see in the image ive attached that with no stress on the cpu my clocks are high. any help would be awesome. thanks

 

The way I have always understood it is that if you are not pushing all of your cores you will get your Turbo Boost clock speeds, temp while factoring in will not always clock it down if your not pushing all of the cores. If your only running on one core, then you get the full turbo boost, 2 cores it drops slightly, 3 cores it drops some more and 4 cores will drop you back to 2.7 GhZ. If your running Prime it is going to load up all 4 cares immediately and drop your clock speeds to keep you from overheating. If it let you run at full power on all 4 cores I imagine it would burn up the chip pretty quickly.

Taken from Intel's website....

Intel Turbo Boost Technology is a way to automatically run the processor core faster than the marked frequency. The processor must be working in the power, temperature, and specification limits of the thermal design power (TDP). This results in increased performance of both single and multi-threaded applications.

Taken from another site...

Turbo Boost is a dynamic feature. There is no set-in-stone speed which the Core i5 or i7 processor will reach when in Turbo Boost. Turbo Boost operates in 133Mhz increments and will scale up until it either reaches the maximum Turbo Boost allowed (which is determined by the model of processor) or the processor comes close to its maximum TDP. For example, the Core i5 750 has a base clock speed of 2.66GHz but has a maximum Turbo Boost speed of 3.2GHz.
However, Intel still advertises these processors by their base clock speed. This is because Intel does not guarantee that a processor will ever hit its maximum Turbo Boost speed. I have yet to hear of an Intel processor which can’t hit its maximum Turbo Boost speed, but hitting the maximum Turbo Boost is dependent on workload ““ it won’t happen all of the time.

Hope some of this helps.

Basically when your playing BF4, your not stressing your CPU, so you get the turbo clock. If for some reason you started to get to close to your TDP then it is going to clock you down and slow itself down to keep the temps and load where it wants them. When your not doing anything and your computer is sitting idle, your temps are not in any danger and there is no load on the cores, hence your 3.7 clock speed. If you launched Prime and it kicked in turbo boost the CPU would probably end up shutting down to prevent thermal damage sooner rather then later.

 

Yea that helps for sure. Thanks. I guess there's no way to manually set my clock speed then? I know the bios is keeping me from being able to overclock. There's no unlocked bios for the new 17 yet ?

 

Unlocked I am not sure , you would probable be best to browse the techinferno forum for that one. You can turn speedstep off but as best I know all that will do it lock you at 2.7 GhZ instead of 3.7 GhZ. Honestly I don't thin you want to lock it that high on all the cores anyways, your looking for overheating if you do that IMO. There should not be any game out there right now that will even come close to maxing out your CPU, I would just leave it as they have it set up and go from there. You might be able to OC it a bit, I am not sure on this either as I have never OCed my R4 nor do I play on OCing my R5 when it gets here next week, I simply don't see a need as it will run everything I throw at it no problem.

 

alright thanks for the explanation. I feel like the CPU is more then enough for today's games. Shouldn't need any overclocking was just curious if it was possible for benchmarking reasons

 

I believe it is possible but I remember reading a thread my our glorious Mr.Fox the other day talking about how the Haswell chips are not that good when it comes to overclocking in general, at least not in comparison to the ivy lineup.

 

yea ive heard the samething. not a huge deal though its enough processing power for now

 

Haswell can go toe to toe with ivy with the right bios but it's not quite as simple to do so.

 

i havent been able to find any unlocked bios yet, but for now im happy with the performance

 

Did you try TechInferno?

 

I got my modded vbios from there but I haven't seen anything for my bios yet