[SOLVED] Dell Optiplex 760 w/ Q9400 Refuses to clock up to full speed

[MtDewFella]

Like the title says, this was an issue with the previous cpu E8500 as well, neither would go above 91% cpu usage with a rare spike to 93% since it has happened with both cpu's I presume it's an issue with the pc itself. It's a Dell optiplex 760 DT (horizontal case that can sit under the monitor, not sff) windows 10 latest stable build, any help would be appreciated note: I tried using throttlestop to try and fix and i noticed that a box titles "disable turbo" was checked and I couldn't uncheck it, related?

 

[Nirmith Akash Anawarathne]

Did you check BIOS for any option that would limit CPU performance? I have seen some C2D prebuilt PCs with such options but hard to say what/where exactly BIOS differ from one to another.

 

[MtDewFella]

Did you check BIOS for any option that would limit CPU performance? I have seen some C2D prebuilt PCs with such options but hard to say what/where exactly BIOS differ from one to another.

I combed through the bios, and tried different settings, but nothing seemed to fix the issue, best I could do was limit cpu sleep states and speed stepping so the cpu ran "hot" all the time but still no higher than 93% (91% most of the time)
Also would "Intel Management engine BIOS extension" do anything

 

[Nirmith Akash Anawarathne]

I combed through the bios, and tried different settings, but nothing seemed to fix the issue, best I could do was limit cpu sleep states and speed stepping so the cpu ran "hot" all the time but still no higher than 93% (91% most of the time)
Also would "Intel Management engine BIOS extension" do anything

I've been using a C2D as a second PC for sometime, what I noticed, they have pretty higher idle temps. Even with no usage except for the system services and all the other mandatory stuff it stayed at 55-60C. i wouldn't wonder why you stuck at below 100% if you have the same situation which means the CPU is throttling. Just see what kind temp you get in normal use.

Also note the clock speed, see whether it reaches what they've promise.

 

[MtDewFella]

I've been using a C2D as a second PC for sometime, what I noticed, they have pretty higher idle temps. Even with no usage except for the system services and all the other mandatory stuff it stayed at 55-60C. i wouldn't wonder why you stuck at below 100% if you have the same situation which means the CPU is throttling. Just see what kind temp you get in normal use.

Also note the clock speed, see whether it reaches what they've promise.

on the q9400 the adverstised clock is 2.67GHz, I'm only getting 2.44GHz, I'll need to check the temps, but there is a bios option to just turn on fan at full speed all the time, could that work?

 

[Nirmith Akash Anawarathne]

on the q9400 the adverstised clock is 2.67GHz, I'm only getting 2.44GHz, I'll need to check the temps, but there is a bios option to just turn on fan at full speed all the time, could that work?

Ya CPU running lower clocks definitely because of the higher temperature.

fan at full speed all the time - You can try this but don't know how much success will it archive, Anyway what kind cooling you have?

[edit]
Better cooling will be the solution so if you not wish to upgrade cooling then use with opened slide panels or use a room fan blowing air towards the CPU fan. (My idea : it's not worth paying for a better cooler as the entire system is way too old and also it consumes lot of power and heat compare to newer low end components so just look forward for a full system upgrade.)

 

[MtDewFella]

Ya CPU running lower clocks definitely because of the higher temperature.

fan at full speed all the time - You can try this but don't know how much success will it archive, Anyway what kind cooling you have?

So I nailed the fan in the on position (damn it's loud) and got the cpu down to 43 C even underload and still underclocked, normal heat sink that came with the pc

 

[MtDewFella]

is it possible that windows is just not reporting usage correctly?

 

[Nirmith Akash Anawarathne]

is it possible that windows is just not reporting usage correctly?

Can be .. use CPU-Z determine the frequency it is much accurate than the task manager.. i think.

 

[MtDewFella]

is it possible that windows is just not reporting usage correctly?

I ask because throttlestop sys tray icon on hover shows info including clock speed, I just thought it was showing stock advertised clock, but i noticed it changes and it does show going upto 2.65 GHz

 

[Nirmith Akash Anawarathne]

I ask because throttlestop sys tray icon on hover shows info including clock speed, I just thought it was showing stock advertised clock, but i noticed it changes and it does show going upto 2.65 GHz

Well it seems normal for that CPU right?

Intel Core 2 Quad Q9400 / 2.66 GHz processor Specs

Intel Core 2 Quad Q9400 / 2.66 GHz processor overview and full product specs on CNET.

www.cnet.com

[edit]
if you want to be precise about you CPU then do a benchmark and compare it will same models in internet.
http://valid.x86.fr/bench/9lxa16

 

[MtDewFella]

okay so it seems windows 10 is just incorrectly reporting speeds, cpu z reports full speed and i booted a linux live usb and checked and it runs full 2.6 GHz as well, sorry for the trouble, thank you for your time

 

[SamirD]

Great to hear it was just a software issue.

Just for reference, I floor the fan on every system I have, many of which are Dells and by doing so you can comfortably run a 95w processor under a 65w heatsink if you do so. I recently got an i3-4130 and flooring the fan there showed an almost 20C difference in the Dell diag program (which apparently changes the fan from floored back to stock for testing so I was able to see the high and low points under both fan modes). Keep those old systems running!