Help me understand intel turbo mode.

[Compman55]

Got a E3-1245V3 and in the bios the turbo mode is turned on. However on intels data sheet, it shows 3.4GHz stock, 3.8GHz turbo.

When I run prime95 and use a program like Speccy or CPUID the cores are full throttle 3398mhz. Are they ever supposed to reach close to 3800MHz?

And no, the temp throttling did not kick in yet as the cores were in the 70's C.

 

[Deders]

Try monitoring the clockspeed with Argus monitor.

It's only likely to reach 3.8GHz with a single core, with both cores in use it will probably be lower.

 

[ShintaiDK]

Its a chip with a max of 4/4/3/2 turbo bins.

That means 3.6Ghz max for 4 threads+.

While temperature is one part, powerdraw is another. So in your workload it might not be able to turbo to 3.6Ghz due to that. It can usually be increased in BIOS.

 

[Compman55]

Its a chip with a max of 4/4/3/2 turbo bins.

That means 3.6Ghz max for 4 threads+.

While temperature is one part, powerdraw is another. So in your workload it might not be able to turbo to 3.6Ghz due to that. It can usually be increased in BIOS.

Can you explain more? Like I said, max I get is 3398mhz, so it never gets to 3.6. Powerdraw I don't get, as that I beleive it is controlled on the die. Secondly other computers i have tested never go higher either.

So do I need to get a program that can load just one or two cores to see what max turbo I can get?

 

[Deders]

Argus monitor will allow you to monitor each core individually in realtime, to give you a better idea of what is going on

 

[sm625]

Prime95 can be configured to load only one core.

Change Number of torture test threads to just 1.

Do that, and you should see the speed hit 3.8GHz at least some of the time if not most of the time. (It will drop off due to windows background tasks causing other cores to be loaded, which causes the turbo to drop.)

 

[Deders]

Depending on how windows balances the load across the cores, you might also need to set the process affinity to a single core from within the task manager.

 

[Compman55]

No dice, even with affinity set to core 0 or core 1 windows still will distribute the load. I must be missing somthing.

 

[coffeejunkee]

I think you should double-check your bios settings. My cpu never doesn't use its full turbo frequency.

 

[Deders]

Do you have the latest bios installed?

 

[TuxDave]

No dice, even with affinity set to core 0 or core 1 windows still will distribute the load. I must be missing somthing.

You followed SM625's advice too?

 

[BSim500]

First of all, double-check Turbo Boost is enabled in the BIOS. Try setting the multiplier to 38x instead of 34x too. Secondly, try a different monitoring program like TMonitor (best - updates it 20x per second) or Coretemp. Some programs just show the default stock voltage. Thirdly, try setting Prime, etc, to just 1x core (and affinity to just 1x CPU) then watch the loading in Tmonitor.

 

[Compman55]

Yes, I did it exactly how he mentioned. I do have the latest bios which is dated 3/2014.

I will recheck the bios setting and get a better monitoring program.

 

[Compman55]

Ok, so the mystery is when at the desktop, the turbo will go up to 3797.8 MHz on some cores so it is working. Yet when you load 1 core full or all full with prime95 it will hang right at 3398 MHz.

 

[Saylick]

If you want to run max turbo clocks on 1 instance of P95, what's worked for me was to run P95 with all threads active, then manually abort each thread until only 1 is left. That 1 thread shouldn't get redistributed across cores again and should kick in the maximum turbo clock. I have a Lynnfield chip so I'm not sure if this process works with newer Intel processors, but you could give that a shot if you'd like.