XW8600 : X5470 : Not Maximum Frequency

[VALA1]

Hi,

Despite the years, I still use an XW 8600 that works great after several updates.

After reading the topics here, https://h30434.www3.hp.com/t5/Software-Archive-Read-Only/xw8600-cpu-upgrade-question/td-p/5069730

I bought 2 "double tall" fans for 2 cpu X5470 (3.33 Ghz) imported from China.
After several tries, I can't get the 3.33 Ghz as expected. It runs at 3.04 Ghz, sometimes at 3.11 Ghz.

Could it be a motherboard parameter?
A problem related to the processor itself?

With the CPUZ tool, when I "stress" the CPU, there is a plateau for the frequency and it's impossible to go beyond it.

Any ideas ?

Thank you in advance for your help.

[DGroves · Accepted solution]

did you buy the HP double tall heatsinks and fan(s) cooler you post is unclear the correct HP part# is 446359-002

it's normal for the cpu to run lower than 3.33 the actual cpu speed will be dependant on cpu load and current thermal temp

if you run cinebench 15 with task manager/performance tab active you can see the real time cpu freq/temp

[VALA1]

Thank you for your feedback

The fans were purchased on this site :
https://www.bargainhardware.co.uk/hp-446359-001-workstation-xw8600-high-perfomance-heatsink-446359-0...

But without wanting to be fussy, there is a difference in frequency between working exclusively on one core (3.13 Ghz max) and on all the cores (3.04 Ghz max).

With CINEBENCH, the indicated speed is indeed 3.34 Ghz but the multiplying coefficient is 7.55. I thought the "missing Mhz" came from there.

In any case, works very well for an old PC!

Best regards,

[DGroves]

cpu-z while a fine program, does not accurately stress one/all cpu(s) to max cpu usage 

this is why i suggested cinebench 15 as it's known to accurately stress one/all cup's and cpu cores to 100 % load

[VALA1]

He is more demanding on the cores, but he does not work 100%.

I understand the hardware or software inaccuracies but I wanted to know where the difference came from and if there was something I could do to get the most out of it without electrical tinkering.

Thank you for everything