CPU Xeon 2445 not boosting

[Simon788]

Hello,

Xeon w5-2445 on my Z4 G5 is never boosting on core boost over 4,0 GHz, tried to check all setting in bios with no effect. Does anyone have some experience on this?

[NonSequitur777]

@Simon788,

Welcome to our HP Community forum!

Your Intel Xeon w5-2445 has a base frequency of 3.10 GHz and a maximum turbo frequency boost up to 4.60 GHz (on one or two cores depending on workload and thermal/power conditions). If you're never seeing it boost past 4.00 GHz, here are some things to check:

1. BIOS Settings:

• Make sure Intel Turbo Boost Technology is enabled in the BIOS.

• Set the thermal profile to "Performance" rather than default or "Acoustic" mode.

• Check for any power/performance limits (PL1/PL2) or current limits* that may be restricting boosting.

 

2. Windows Power Plan:

• Use the "High Performance" or "Ultimate Performance" plan in Windows Power Options.

• Avoid "Balanced" mode which may favor lower frequencies.

• Try the freeware PassMark Performance software to see how your Xeon w5-2445 compares to the average CPU mark of 32,269: https://www.cpubenchmark.net/cpu.php?cpu=Intel+Xeon+w5-2445&id=5452.

 

3. Thermal & Power Limits:

• Run a utility like HWiNFO64 or Intel XTU to monitor:

  • CPU temperature

  • Power draw (PL1/PL2)

  • Thermal throttling

  • Current limit throttling

  If your CPU is near its TjMax or hitting power limits, it won't boost to max turbo.

 

4. Workload Type:

• Turbo Boost is opportunistic and depends on the workload. Short, single-threaded workloads are most likely to trigger full boost.

• Try a single-threaded benchmark like Cinebench R23 (single-core mode) to test boost behavior.

 

5. Firmware/Driver Updates:

• Make sure your BIOS is up to date: https://support.hp.com/us-en/drivers/hp-z4-g5-workstation-desktop-pc/2101336703.

• Install the latest Intel chipset drivers and HP performance tools (such as HP Performance Advisor).

* To check for power/performance limits (PL1/PL2) and current limits on your HP Z4 G5 with a Xeon w5-2445, follow these steps:

---

Method 1: Use HWiNFO64 (Recommended):

1. Download and install HWiNFO64 (from https://www.hwinfo.com)

2. Run HWiNFO64 in "Sensors-only" mode

3. In the sensors list, look for:

   • CPU Package Power (shows real-time power draw)

   • Power Limit Exceeded – if this turns YES, you're being throttled by PL1 or PL2

   • Current Limit Exceeded – means the CPU is hitting amperage limits

   • Thermal Throttling – tells if temps are too high

   • Core Max Clock – helps track turbo behavior

4. Expand the “CPU [#0]: Intel ...” section to see limits:

   • PL1: Long duration power limit (usually 125-watt or lower on workstations)

   • PL2: Short burst limit (often 200–250-watt on high-end Xeons)

   • Tau: Duration PL2 can be maintained (e.g., 28 seconds)

If PL1 or PL2 is too low or exceeded, turbo boosting gets cut short or limited to lower frequencies (e.g., 4.00 GHz instead of 4.40 or 4.60 GHz).

---

Method 2: Intel Extreme Tuning Utility (Intel XTU):

NOTE: XTU may not support Xeon CPUs or HP BIOS locks, but worth trying:

1. Download from Intel: https://www.intel.com/content/www/us/en/download/17881/intel-extreme-tuning-utility-intel-xtu.html

2. Open XTU → Go to Advanced Tuning

3. Look for:

   • Turbo Boost Power Max (PL1)

   • Turbo Boost Short Power Max (PL2)

   • Turbo Time Window

   • Core Voltage / Amps

If these settings are grayed out or locked, it's because HP locks them in BIOS -common for workstations like the Z4 G5.

---

HP BIOS Insight (if unlocked):

If you reboot and enter BIOS (F10):

• Go to Advanced → Power or Thermal Configuration

• Look for anything like:

  • Turbo Power Limits

  • Current Limit Overrides

  • Performance Tuning

It is very likely that Z-series BIOS setups hide or lock these, but worth checking!

Kind Regards,

NonSequitur777

[Simon788]

thank you for your reply!

I made all steps you are describing below and widely using HWinfo64, Cinebench, AIDA64 and others. But even after bios settings check and testing all options (I can not get to direct setting of PL limits, but HWinfo is showing PL1 175W static and PL2 210W static), all firmware and drivers installed, windows power plan set to "power", the core frequency never goes over 4000 Mhz on any of cores. Temperatures are around 40 in the idle till 80 under long lasting load, no any throttling reported, total power consumption under cinebench multi core load is max 185W never more, none frequency of any core never goes over 4000 Mhz nor mutlicore load, idle, light loads, single core loads...

Normally I am familiar with working on most of nowadays CPUs on many installations, but this is my first HPs experience, would be thankful for any other advice.

S.

[NonSequitur777]

@Simon788,

Almost looks like this is how well your processor is ever going to work in your PC.

Did you look at your average PassMark processor score, and why don't you try out Userbenchmark, and see how well your processor compares to other Xeon w5-2445 performance scores.  Meaning, if your CPU scores between a 93% and 97% processor benchmark, then for sure this is the best you could expect from your CPU.

Kind Regards,

NonSequitur777

[Simon788]

Thank you again, but is saying nothing about the reason why the core boost is not reached, in general CPU meets the average values from mentioned benchmarks. But I am still wondering if this "clock limits to 4GHz" is a matter of HP specific bios settings or is a case of my specific CPU....,

Thank you for your time

[NonSequitur777]

@Simon788,

Trust me, I understand the issue.  I'm afraid that HP doesn't provide the (software) tools to address it.

Kind Regards,

NonSequitur777

[Simon788]

OK, thank you for your assistance and support

[NonSequitur777]

@Simon788,

You're welcome and best wishes.

Kind Regards,

NonSequitur777

[Simon788]

@NonSequitur777

Thank you for the support below, I would like to ask one more question regarding the possible CPU upgrade, would it be possible to upgrade CPU in the same MB to W7-2495X? or what are the condition for this eventual upgrade, thank you in advance.

Simon

[NonSequitur777]

@Simon788,

Yes, the mighty Xeon w7-2495X is compatible with your HP Z4 G5 Workstation as seen with this User: HP Z4 G5 Workstation Desktop PC Performance Results - UserBenchmark.

I would make sure you got the latest BIOS update for your PC: version 01.02.17 Rev.A, released in February 2025: https://support.hp.com/us-en/drivers/hp-z4-g5-workstation-desktop-pc/2101336703.

Kind Regards,

NonSequitur777