Is Intel turbo boost for 2 cores or all 4 cores on 4790k?

[poohbear]

hey all, i've been googling whether turbo boost is for all 4 cores or just 2, but can't seem to find any results. For the desktop 4790k that turbo boosts to 4.4ghz, is that turbo boost for all 4 cores, or just 1 or 2 cores?

also, intel's specs say its max safe temp is 72c "Tcase", what does that mean exactly? is that the temp reported in HW monitor?

thank you for any clarification.

 

[Yuriman]

Turbo bins are based on number of cores active. A quick google search didn't reveal any tables for me, but my 3570K at stock runs at 3.4GHz and may turbo to 3.6 with 4 cores, 3.7 with 3 cores, and 3.8 with 1 or 2 cores. If I were to guess, I'd bet it's 4.2 with 4 cores, 4.3 with 3, and 4.4 with 1 or 2 cores.

Can't remember the exact meaning of Tcase, I think it used to be a package sensor that's near the processor.

 

[poohbear]

I see. So turbo boost @ 4.4ghz is not 4.4hhz with all 4 cores then? I'm manually overclocking to 4.6ghz and noticed temps jumped quite a bit despite a slight increase in vcore, guessing that's cause they're all at 4.6ghz then.

HW monitor is reporting 75c max temps on 1 core running BF4, is Tcase @ 72c what's reported in HW monitor and other software monitoring tools?

 

[Yuriman]

I see. So turbo boost @ 4.4ghz is not 4.4hhz with all 4 cores then? I'm manually overclocking to 4.6ghz and noticed temps jumped quite a bit despite a slight increase in vcore, guessing that's cause they're all at 4.6ghz then.

HW monitor is reporting 75c max temps on 1 core running BF4, is Tcase @ 72c what's reported in HW monitor and other software monitoring tools?

Yeah, not all 4 cores are going to 4.4GHz at stock unless you've enabled an option for it in bios. I think it's called "multi core enhancement" on Asus boards, not sure if it's the same across the board.

I don't believe Tcase is what it's using. TJ max is ~100c, which is probably from the sensor HW monitor is using.

 

[Majic 7]

My system turbos to 4.4 on all cores with XMP enabled. Performance is also enabled in Bios but it was enabled already the first time I went into Bios. I don't overclock and probably won't ever. I do my financial stuff on this computer and don't want to take a chance with corruption, however slim.

 

[Roland00Address]

The default profile for the 4790k with turbo bins is

2/2/3/4

The non boosted state is 4.0 ghz. Each tick of the multiplier of the 4790k increases the processor's speed by a 100 mhz so the breakdown is this.

4 cores 4.2 ghz
3 cores 4.2 ghz
2 cores 4.3 ghz
1 core_ 4.4 ghz

My system turbos to 4.4 on all cores with XMP enabled. Performance is also enabled in Bios but it was enabled already the first time I went into Bios. I don't overclock and probably won't ever. I do my financial stuff on this computer and don't want to take a chance with corruption, however slim.

Many motherboard manufacturers in the options have the default at max where all 4 cores can turbo. They make it the default since it makes them look better in reviews.

 

[poohbear]

Ok great, in the Asrock bios theres also an option called "multicore enhancement". The description says "performs the highest frequency on all CPU cores at the same time". It's enabled by default. So that means all my cores are running @ 4.4ghz in turbo mode yea?

If so, then there's really no point in overclocking to 4.6ghz cause it requires an extra 1.5vcore just for that 200mhz overclock. But i wanna confirm that all 4 cores are indeed running @ 4.4ghz with that setting before coming off this overclock.

Roland, so the mobo manufacturers can override 4 cores @ only 4.2ghz with the multicore enhancement option in the bios?

If 100c is the max temp then im good, i max out @ 75c underload in BF4.

 

[Yuriman]

Ok great, in the Asrock bios theres also an option called "multicore enhancement". The description says "performs the highest frequency on all CPU cores at the same time". It's enabled by default. So that means all my cores are running @ 4.4ghz in turbo mode yea?

If so, then there's really no point in overclocking to 4.6ghz cause it requires an extra 1.5vcore just for that 200mhz overclock. But i wanna confirm that all 4 cores are indeed running @ 4.4ghz with that setting before coming off this overclock.

Roland, so the mobo manufacturers can override 4 cores @ only 4.2ghz with the multicore enhancement option in the bios?

This is correct.

 

[poohbear]

Is there any program that can show me what each core is running at? CPU-Z just reports 4.4ghz, & HW monitor is just a temp prog.

edit: found the program Argus Monitor that can show each individual core's speed. All are running @ 4.4ghz.

Thank you for the help guys!

 

[Majic 7]

I use this from Intel. Works with 7, 8 and 8.1. https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=24075&lang=eng&ProdId=3483 You can also check your motherboard site and see what utility they have. The Intel one works pretty good, though.

 

[Roland00Address]

Ok great, in the Asrock bios theres also an option called "multicore enhancement". The description says "performs the highest frequency on all CPU cores at the same time". It's enabled by default. So that means all my cores are running @ 4.4ghz in turbo mode yea?

You already got the answer but I want to empathize other things.

The cpu will not run at 4.4 ghz if its in danger of overheating the temperature sensor and all that still work. It can still throttle down to 4 ghz or a lower state to save the computer's bacon.

Second things like windows power profiles can also mess with the clock speed. This is why desktops which don't really care as much about power usage are often at a more power using profile while laptops which care about battery life run a more balanced or battery saving mode.

---

And now you probably realized why for the most part OC for extra performance is for the most part dead. You with one flip of the switch in the bios option is running 90 or 95% of the speed of a non extreme overclock. People now overclock not to save money but instead for fun and ego.

Thankfully Intel released two versions of the 4790 one with a clock speed that is 400 mhz higher (the 4790k) for a reasonable price increase. That said the k behind the processor now a days is mostly marketing and not really going to make pronounce differences in how you use the computer.

 

[BonzaiDuck]

Yeah, not all 4 cores are going to 4.4GHz at stock unless you've enabled an option for it in bios. I think it's called "multi core enhancement" on Asus boards, not sure if it's the same across the board.

I don't believe Tcase is what it's using. TJ max is ~100c, which is probably from the sensor HW monitor is using.

[For OP's TCASE question -- to clarify:]

Back in the day, with Pentium 4, there was only a single temperature sensor. It may have been called "TJunction" or TJ then. Who remembers? I don't.

The TCASE spec may still be included with Haswells. It is essentially a "thermal design" spec or a case guideline that includes ventilation. It is essentially a measurement of temperature dead-center on the IHS, which is really impossible without special provision -- because there's no sensor there.

So TCASE for current-day processors should be about 72.5C.

At some point, someone over at Tom's HW actually did the measurement. This was done for the Conroe and likely the Kentsfield C2Q. I think I read it just when the Wolfies and Yorkies were being released. But the upshot was that the difference between TCASE and the AVG(c0,c1,c2, c3) of TJ measurements was between 10C and 15C.

I use the "guesstimate" of 10C, if I need to worry about it. So, if my 2600K is running at full load with LinX or IBT, showing an average temperature of 73C, then I'm about 10C within the TCASE spec. I assume that the mythical and arcane "spec" links case design and thermal effects on silicon. I wouldn't really know for sure, though.

Look at it another way. Most folks tend to wind up their overclocking project when they can't keep the Tj temperatures lower than 85C. And that -- by my understanding -- is still close to the TCASE spec.

 

[GLeeM]

My system turbos to 4.4 on all cores with XMP enabled (snip) I don't overclock and probably won't ever.

When you enable XMP you also enable "multi-core enhancement" which is Asus auto overclocking!

Intel® Turbo Boost Technology 2.01 automatically allows processor cores to run faster than the rated operating frequency if they’re operating below power, current, and temperature specification limits.

Intel Turbo Boost Technology 2.0 is activated when the Operating System (OS) requests a frequency higher than the rated frequency of the processor. Whether the processor enters into and the amount of time the processor spends in the Intel Turbo Boost Technology 2.0 state depends on the workload and operating environment.

Quote from here: http://www.intel.com/content/www/us...ology/turbo-boost/turbo-boost-technology.html

 

[poohbear]

Thank you for clarifying further Roland, Bonzaiduck & Gleem.

Yes theres no point overclocking on this chip, 200mhz extra at a hefty 1.5vcore isnt worth it for me. HW monitor reports 70~75c in BF4 @ 4.6ghz, whereas at default 4.4ghz its 55~60c max.

Thanks for explaining tcase, so 72c +10c to get the software limit like in HW monitor, im still well within safety limits.

Btw in argus monitor, my cpu is always @ 4.4ghz, even when idle. Is that supposed to happen? I have all my powersaving C states enabled (c1, c2, c3, c6 & c7), shouldnt it drop to 1ghz when idle on the desktop? My old 2500k used to drop all the time when idle.... it"s only @ 32c idle, is it all temperature based?

 

[Dave3000]

My system turbos to 4.4 on all cores with XMP enabled. Performance is also enabled in Bios but it was enabled already the first time I went into Bios. I don't overclock and probably won't ever. I do my financial stuff on this computer and don't want to take a chance with corruption, however slim.

You technically are still overclocking that CPU on 4-core and 3-core loads at 4.4GHz. That's a 200MHz overclock above stock turbo (not stock base) on 4-core loads and 100MHz overclock above stock turbo on 3-core loads on that CPU.

 

[Dufus]

Look at it another way. Most folks tend to wind up their overclocking project when they can't keep the Tj temperatures lower than 85C. And that -- by my understanding -- is still close to the TCASE spec.

Tcase temperature will be closer to Tj at low power. With higher power it is further away. Information can be found in the publicly available thermal specifications from Intel's website.

The ΨCA point at DTS = -1 defines the minimum ΨCA required at TDP considering the worst case system design TAMBIENT design point:

ΨCA = (TCASE_MAX – TAMBIENT_TARGET) / TDP

For example, for a 95 W TDP part, the Tcase maximum is 72.6 ºC and at a worst case design point of 40ºC local ambient this will result in:

ΨCA= (72.6 – 40) / 95 = 0.34 ºC/W

At Tjmax DTS = 0. As you can see from the above Intel example when operating at 95W Tj will be -1 from Tjmax when case temperature is at 72.6ºC. If Tjmax is 100ºC then the difference between core and case will be close to 30ºC at 95W.

Simplifying*** the above, thermal resistance between core and case ΨJC can be taken as ~0.3ºC/W. TDP is a specification and not the maximum power the CPU can draw so if overclocking and say drawing 150W the difference becomes 45ºC. This means if your core temperature is 95ºC then Tcase will be at 50ºC while softwares using the 10ºC offset will be telling you it's at 85ºC. Big difference. Unsurprisingly, Intel does not show case temperature in XTU.

*** Manufacturing isn't perfect, thermal resistance may be better than worse quoted example from one CPU to another. Thermals are multi-path so a bit more to it than the simplified version.

@poohbear, any multiplier above the HFM is considered a turbo bin. With the 'k' processors you can set them all the same or stepped. With stepped multipliers you need C3 or higher active to use the higher set stepped turbo's. If running flat then not required. There are 4 voltage modes you can use with Haswell, default, offset, fixed, and adaptive (with or without offset). Do be aware though if using negative offsets HWMonitor reports these incorrectly as pointed out last year. HWinfo32 was quick to fix this but it seems going from HWMonitor V1.24 to 1.25 the problem is still there.

 

[SeanJ76]

Turbo=two top cores. For instance, say you have your 4690k set to 4.6ghz and did not choose "sync all cores" in the bios, naturally the turbo will push cores 1 and 2 up to 4.7 and 4.8Ghz. Depends on how you set it up in the bios, some boards DO NOT have these specialized options(Asus does), so if you wondering, "why don't I have these options?" its because you have a cheap board.

Yes, it is called "multi-core enhancement" on Asus boards, and there are several options to choose from(Msi gaming boards do not have this option).

 

[hawtdawg]

mid-70's is perfectly comfortable for an OC'd 22nm chip. Even mid-80's is considered safe.

 

[Dufus]

Yes, it is called "multi-core enhancement" on Asus boards, and there are several options to choose from(Msi gaming boards do not have this option).

That sucks. I thought most boards allowed you to adjust each core bin individually, even my MSI laptop allows me to do this. For my older 2500k DT it was useful because although it would hit 5GHz easily even without PLL overvoltage, the cooling was insufficient to run all cores at 5GHz so had 46,47,48,50 set.

Unfortunately reduced features does happen and is kind of understandable. Back in the P67 era I remember ASUS enabled memory timing adjustments in the OS with MemTweakIt for their top board but locked out the necessary registers in BIOS for all the lower boards (read only). Luckily though a BIOS mod and a version of MemTweakIt from CPUID could fix that. The ASUS MemTweakIt software was also set to run with write permission only their top board too IIRC.

 

[antihelten]

A quick google search didn't reveal any tables for me.

All* i7 Extreme CPUs:
http://www.intel.com/support/processors/corei7ee/sb/cs-032277.htm

All* i7 CPUs:
http://www.intel.com/support/processors/corei7/sb/CS-032279.htm

All* i5 CPUs:
http://www.intel.com/support/processors/corei5/sb/CS-032278.htm

*desktop