Another T43p CPU Upgrade Question

[chocorem]

Having a M750 1,86Ghz, I just found a processor with these specs....

Spec Number SL7VB 780 2.26 GHz Sonoma Centrino CPU
Processor Frequency 2.26 GHz CPUID String 06D8h
Package Type 478 pin Core Voltage 1.400
Bus Speed 533 MHz Thermal Guideline 27W
Core Stepping C0 Thermal Spec 100 C
L2 Cache Size 2 MB Manufacturing Technology 90 nm
L2 Cache Speed 2.26 GHz Bus/Core Ratio 17

I think it will fit ? what do you think ?

Greg

[ulrich.von.lich]

Yes that CPU will fit. I just did the upgrade a couple of weeks ago. It works great but I'm afraid it'll be much hotter than the 1,86Ghz you are having. The highest temperature I've seen is 86C. And it's still winter here in Paris.

Hope it helps. And yes, the "maxed out" feeling is great!

[chocorem]

How much did you pay for the CPU and where did you find it ?

Greg

[ulrich.von.lich]

I found it on ebay and paid about $240 with shipping. I visited some local computer stores but couldn't find anything interesting. This CPU is quite rare and I'm afraid you'll have to purchase it online.

Here's two auctions on eBay France right now. If you don't mind purchasing it aboard, here's a reliable seller who ships internationally. And he always has a Pentium 780 to sell.

[sjthinkpader]

Yes that CPU will fit. I just did the upgrade a couple of weeks ago. It works great but I'm afraid it'll be much hotter than the 1,86Ghz you are having. The highest temperature I've seen is 86C. And it's still winter here in Paris.

Hope it helps. And yes, the "maxed out" feeling is great!

The T43/T43p are specified to use 780 CPUs. intel 780 spec has a max Tj (junction temperature) of 100 deg C. The thermal diode has a max offset of 11 deg C. So your computer could shutdown around 89 deg C.

[awolfe63]

If you are getting that hot - you probably have poor heat sink contact or a fan problem.

[ulrich.von.lich]

Do you guys think the temperature I'm getting is unusual? (86C for a 2.26Ghz CPU being 100% occupied for like 15 minutes) I bought a new fan and applied AS5 on the CPU (nothing on the GPU). I don't know how to improve the surface contact and I doubt it'd be the temperature I get if the AS5 wasn't applied correctly.

sjthinkpader, what you said is pretty scary... So shutdown temp = junction temperature - thermal grease offset? If I remember right, Pentium M (maybe P4M too) CPUs will automatically lower its operating frequency before reaching the shutdown temperature. What is the threshold temperature?

[awolfe63]

Not if it happens fast. I had a bad fan on my first T42. The CPU would hit 90C and the machine would just shut off instantly.

86C is borderline - but my experience upgrading T42s with 2.1GHz Pentium M 765 and other machines with 780s is that 70C at 100% is more typical.

[ulrich.von.lich]

Thanks for the info awolfe63! May I also know the idle temperatures of those CPUs?

Could a bad CPU run hotter?

[awolfe63]

I get around 37-42C idle. Idle temp. seems to depend a little more on how warm the room is.

A bad CPU could get hotter - but to be fair, even a good one can. 86C at full-bore is within spec and probably would have passed Intel's testing. I have just notices that it is what I have seen when I have a fan problem or old-dried up goo on the heat sink.

[ulrich.von.lich]

Wow, impressive!! When I get a fever, it'd be something around 39C I think. Do you use NHC or any software to undervolt your T42? Does its fan kick out when idling? Is it a 14" or 15" model? Does the GPU run hotter?

I think I'll re-apply the AS5 to see if things will change.