Thinking about Duo 2 Core upgrade on Z61m? Read this.....

[vital-analitix]

I already hinted in another post that I would do a write up of upgrading my Z61m from a 1.83 Core Duo to a 2.0 Ghz Core 2 Duo.

Summary: Unless you can absolutely can define why you need an upgrade then do not upgrade. For pure number crunching I feel that the machine gets too hot (even with the 1.83Ghz CPU).

[I do not want to see the temperature above 65 C. for a variety of reasons.]

Having done the same in an A31 (going from 1.8 Ghz to 2.6 Ghz) I was emboldened to do same on this machine.

Reason is that during the past 6 months of using this machine I started to have performance issues and in the end I traced this down to CPU I/O bandwidth.

Since the busspeed is locked at 667Mhz all I could do is replace the Core Duo (2 Mb L2) with a Core 2 Duo (4 Mb L2). (larger L2 cache should improve performance)

After searching around and making sure that my chipset would support the new Core 2 Duo CPU the 2.0 Ghz was ordered.

I printed out the relevant parts of the hardware maintenance manual, got the antistatic pad and wristband out and took to task.

It all went well and I dropped the new CPU in place, put on the Arctic Silver 5 and cleaned off the old gunk from the heatsink.

Put the heatsink in place, put in the screws and tighten up (but not all the way - just left enough slack on the screws to move the heatsink slightly sideways to "settle it" and "slide it slightly around" in order to rub the Arctic Silver in.

Removed the heatsink again and did a check on how well Arctic Silver had spread.... to my surprise it seemed that the CPU was only half touching.... put the heatsink in again and started to put a put pressure on different area's: <explicitive!> the GPU was not even touching either! <another explicivite!> what is going on here? Is the CPU of a different thickness? Out comes the CPU and gets compared with the 1.83Ghz. No, it looks like same height...

Drop the old CPU in and do the same check with the Arctic silver... now that one is only touching on one half too....

In the end it turns out that when locking the CPU in place I had to push the CPU down because it seemed to sit slightly up....

OK, satisifed that now the CPU and heatsink are properly installed I finish putting the keyboard and palmrest back and start the machine up.

All is fine....

Start up CPU-Z. CPU-Z reports a 1.3 V voltage....

Now normally I am not ruffled quickly (due to my occupational activities) but my heart stopped a beat (or two): these CPU's are only supposed to have a max of 1.25 volts on maximum speed an 1.075 volts when at minimum speed.

And we are at minimum speed......

CoreTemp reports wrong voltage, Rightmark reports correct voltage, NHC reports right voltage, Intel's TAT.exe reports proper voltage .... Hmm... can relax a bit... but what is going on?

Cut the long story short: turns out that I needed a later version of CPU-Z. (CoreTemp was the latest version.)

Since I have sufficient CPU power and was only looking to improve the I/O bandwidth I have created a new powerscheme with "balance all settings". This setting reduces the fan noise. (rather than "maximum performance").

Overall the temperature is about the same as with the old CPU (around 60 C) and the performance has improved.

Before the combined CPU reading always seemed to hover around 50% (I monitor this constantly for occupational reasons on which I will not further elaborate) and now it hovers around 35 - 38% (!).

More importantly it seems to have alleviated my I/O bandwidth: I can now switch between different parts of my applications and it looks like the CPU has already the required data in its cache (instant switching) rather than to have to swap something out and get something else in. (do not want to elaborate on this) But most definitely in my circumstances the performance has considerably improved. (am doing some very complex multitasking on several fronts and am also running a production database of approx 500 Mb - 150M rows).

Other performance tests did not show much of an improvement over the old CPU. If it was not for my very specific situation and the complex running of several applications with each a high I/O throughput then I would not regard it as a worthwhile upgrade (unlike on the CPU change on my old A31's).

The Z61m seems to have the performance of the whole of its parts to have well balanced.

On the mechanical front: I did not feel that the Z61m was as "tank like" build as the A31's - found the whole giving me an impression of being (let me express this carefully <wink>) somewhat fragile.

In any case I will be more carefull with this machine than with the A31's that it replaced.

[cmarti]

Nice review!

Did you notice any difference when performing video enconding?
Any improvement?

[vital-analitix]

Cannot tell you since I am not involved in video encoding or any rendering. But I have noticed good video performance, previously I had a lot of screen "flicker" and that has almost completely disappeared.

[jkahng]

vital-analitix
thank you for the detailed experience...
i plan to upgrade later when the cpu prices drop a little as i don't see a need for the extra performance right now...

you mentioned less "flicker" can you give us a little more detail? i too am curious about bump in video performance....

thanks
jkahng

[vital-analitix]

You ask about less flicker.

Perhaps the best explanation I can give is that my applications do a recalculation and then redraw graphs on the screen.

This happens anywhere between once in x minutes to hundreds of times every second. Above a certain amount of having these recalculations / redrawings there would be a very tiring "screen flicker" giving me headache (pretty hard on the eyes).

I had already alleviated this by switching to 16 bit color (on my A31 I had it even lower, had it to 256 colors) which helped matters. Now I have reverted back to 32 bit color and hardly notice the screen being "updated".

Hope this helps.

Marinus

[sapibobo]

To decrease fragile feeling of Z series case, try to tighten the screw below the case. All of them. I did it, and now the Z series feel like tank and less fragile than before.

[wacktool]

Not as nice as your chip, but i just took out the 1.66 and dropped in a 1.83. easy and fast, but dont see any difference in performance, lol.

[314]

On the stock unit there is a foamish pad between the GPU and the heatsink. Some people have suggested replacing this with thermal paste like as5. But unless that paste is think layed down think enough it seems like it won't even touch the heatsink. What are your thoughts on this and can a few people give their pre and post GPU temperatures?

An additional question: there are actually three different chips being cooled by the heatsink/pipe. I understand the GPU and CPU, but what is the this one?