Xeon E5 Turbo Boost Question

[PowerPie5000]

This is hopefully a quick one.... My Xeon E5 1660 V2 is supposed to have a max turbo boost of 4.0GHz, but the highest I've seen it reach so far is 3.9GHz (very rarely) and it usually tops out at 3.8GHz 90% of the time. Another strange thing is some utilities detect it as a Xeon E5 1620 V2 which has a max turbo of 3.9GHz (although that is a 4 core chip and mine is a 6 core).

The BIOS detects the CPU correctly as a Xeon e5 1660 V2 (6 cores/12 threads). The motherboard is an Asus Z9PA-U8 with the latest BIOS version (not too sure about the ME firmware part of it though?).

Does anyone have any ideas on what could be happening? Cheers

 

[MagicBoy]

Turbo speeds depend how many cores are active and on temperatures. For that chip :
3800 MHz (3 or more cores)
3900 MHz (2 cores)
4000 MHz (1 core)

I'd guess it's keeping 3 or more cores active...

 

[PowerPie5000]

I'm also now guessing it must be constantly running 2 or more cores at a time. It's the first processor I've had from Intel that couldn't reach it's max advertised turbo frequency, and I've had a few! I even tried manually adjusting the core ratios in the BIOS which didn't do much either. Maybe I'll go through all the power options in the BIOS and windows next.

 

[MagicBoy]

I've got an X5672 in a second system that's similar. It's 3.2GHz with 3.46Ghz and 3.6Ghz turbo available. It spends most of it's time at 3.46GHz. Latest 1709 Windows 10 seems to like keeping all the cores ticking over with a single threaded app.

Here's a cinebench single threaded test with default behaviour :

Forcing cinebench to have affinity to a single core does as you'd expect ... and benchmarks (unscientifically) a single point lower.

 

[ltron]

On my old I7 940 you had to enable C3/C6 power states in the Bios for the top single core turbo boost to work otherwise it would be 100MHz lower.

 

[MagicBoy]

Cheers, I'll take a look. Mine's a old Dell workstation, so unsure if the option will be there...

 

[wam7]

I've got the same CPU with the system in my sig but mine is clocked to 4.8Ghz, though I do remember seeing one core very briefly go to 4Ghz when at stock. Use the Clocks tool option in CPU-Z to see what speed each individual core is at.

CPU-Z also wrongly names it as a 1620

 

[PowerPie5000]

On my old I7 940 you had to enable C3/C6 power states in the Bios for the top single core turbo boost to work otherwise it would be 100MHz lower.

That did the trick!... For some reason the C-state options were disabled in the BIOS (EIST/SpeedStep was still enabled). I loaded the optimised defaults and it enabled C-states up to C6 and now I occasionally see the cores reach 4GHz. It doesn't boost to the maximum as often as other Intel processors I've owned, but at least now I know it's working.

Cheers

I've got the same CPU with the system in my sig but mine is clocked to 4.8Ghz, though I do remember seeing one core very briefly go to 4Ghz when at stock. Use the Clocks tool option in CPU-Z to see what speed each individual core is at.

CPU-Z also wrongly names it as a 1620

CPU-Z clock pretty much shows the same results as HWinfo. I find it strange how some utils such as CPU-Z and Speccy detect the CPU as a Xeon e5-1620 V2 which is a quad core. Even 3DMark got it wrong once too.​

 

[wam7]

CPU-Z clock pretty much shows the same results as HWinfo. I find it strange how some utils such as CPU-Z and Speccy detect the CPU as a Xeon e5-1620 V2 which is a quad core. Even 3DMark got it wrong once too.

Yes, quite strange. In all the many CPU's that I've used CPU-Z on it is the very first time I've seen it wrongly name the CPU.

 

[ltron]

That did the trick!... For some reason the C-state options were disabled in the BIOS (EIST/SpeedStep was still enabled). I loaded the optimised defaults and it enabled C-states up to C6 and now I occasionally see the cores reach 4GHz. It doesn't boost to the maximum as often as other Intel processors I've owned, but at least now I know it's working.

Cheers

That's great news, I'm glad it worked for you.