CPU upgrade in dm4-1xxx

[Woodwood]

I'd like to open a discussion about CPU upgrade possibilities for dm4-1xxx's

The Maintainence and service manual (c02615687 or c03106715 - I don't know why these have different ref. nos, they appear to be the same document) gives a list of compatible and interchangeable CPU's, as I understand it.  The most advanced of these is the core i7-640M, 2.80-GHz (SC turbo up to 3.33 GHz), 4-MB L3 cache

The job of installing a new CPU requires a virtually complete disassembly and reassembly of the laptop, as given in the manual or one of a few instructional videos and guides on the internet.  This is a long process, but it is the same one for cleaning the fan properly.

Is it true that the CPU I mantion above will function at its best in this computer ? (or have I misunderstood the guide)

Has anyone replaced the CPU in such a model ? I'd like what their experiences were (not only for upgrading, but simple replacement of e.g., a defective CPU).

Finally, in W7 at least, in the 'about my computer' page (sart > R-click Computer > Properties) a Windows Experience Rating is available, and if that is clicked it gives scores for the different parts of the system.  This can give an idea of what is limiting the computer in different areas, and how these affect you depends on the tasks you want to perform.

The question about this, is it possible to simulate this and generate the scores for different configurations of 'upgrades' to get an idea of what difference they would make before even acquiring the hardware ?  How would one do this ? Would it be necessary to get software from HP or Microsoft, for example ? 

Woodwood

25.March.2017

[WAWood]

@Woodwood

To answer your questions ...

The processor models listed in the Maintenance manual are the ones that will work.  The fastest one listed there is the fastest one for your laptop -- and yes -- you often have to completely disassemble the laptop, including removing the old processor.

You would then have to obtain the proper thermal paste, remove the old paste, and apply the new paste.

Also, since the faster processors generate more heat, if there were any cooling fins or pad on the old one, you would need ones for the new processor.

No you can not "simulate" the results of the Windows Experience Rating.  You CAN manually alter the rating so that it shows false results -- but that accomplishes you nothing -- it just gives you a set of fake values.  Folks have tried this in older PCs because enhancend video settings were not presented until the video performance rating exceeded a certain level, but they found out that faking the ratings did not accomplish anything.

[Woodwood]

Thank you Provost Wood.

I don't think there is a special thermal problem with upgrading any of the CPUs klisted in the service anfd maintenance manual: based on the i5-430M (2.27GHz) and the i7-640M (2.8GHz)  both having a TDP of 35W (is this the best parameter to compare ?) and both sharing max. temp of 105C

Many of the manufacturers (e.g., arctic silver) thermal pastes (TIM) recemmend removing all pre-applied thermal material and pads from  new processors before application of their heatsink compound.  In the case of HP notebooks the heatsink, if present, is integrated into processor or/and the fan assy (at least in dm4s): there are no cooling fins.

I assume that any reputable thermal paste would be ok.  (for desktops I've used AS Ceramique, I think it's called)

I don't want to maanually alter the Windows Experience ratings, I want to change the hardware inputs to determine the effect on Windows Experience ratings: I think you understood this.  It must be possible to do, but apparently procedures have not been implemented.

Woodwood

26.March.2017