4w increase in TDP a problem in Laptop?

[jardows]

Looking at upgrading an old laptop from a Core Duo to a Core 2 Duo. This laptop does have socketed processors, and can take an upgrade, and I have disassembled plenty of laptops for repair and upgrade before, so we can get those caveats out of the way.

When I have upgraded processors on laptops before, I have always made sure everything matches as much as possible, including TDP, but there is a difference in this one. The original processor is 31w, and the upgrade processor is 35w. I don't think that the 4w difference will be a problem, but I wanted some input before I purchased the processor. Anyone know if the threshold of the cooling solutions in laptops are so limited that the 4w difference will cause problems?

If no one knows, I'll purchase the processor and test it myself, and report back.

 

[Hail The Brain Slug]

I think it honestly depends on the laptop. I have a 2014 Razer Blade that I've flashed modified MB and Vbioses to, overclocking and unlocking stuff.

From my experience doing that, I've learned that there may be more effects to increasing the wattage limit than may be apparent. The biggest issue I ran into was that if I increased the wattage limits too much, for some unknown reason it would start to throttle. I concluded that I must have surpassed the power delivery capability of the battery/charging system. For that laptop, increasing the GPU tdp limit from 90->100W and increasing the CPU limit from 35->45W caused it.

Second issue I saw was that the CPU already ticked down a few multipliers under full load due to the power limit, yet temps still approach 90-95C. When I upped the limit to 45W temps skyrocketed causing more throttling.

I suppose my point here is it depends on the thermal dissipation ability of your laptops cooling solution as well as its power delivery. I would suggest doing some stress testing with the 31w cpu to see if temps are pretty high under load or if there is some thermal headroom there.

As for power delivery, I imagine if you check the bricks rated power and check your laptop under load (killawatt or something) you can see if its pretty close to the limit there or if there is headroom as well.

This may seem like splitting hairs over 4 watts but there's a good chance the new 35W CPU may actually turbo as high as 45W for the 28 second limit, if the bios allows it to, and that might be too much.

 

[Yakk]

Laptops are generally engineered to more stringent requirements and therefore usually have way less leeway in terms of going off spec compared to desktops. Might still work, but every Watt of power is closely counted when they engineer portable gear.

 

[andy2000]

It will probably be fine. Was this same model laptop ever offered with a Core 2 Duo? If it was, try to find out if they used a different heat sink/fan in the Core 2 Duo version. For example, the Thinkpad T60 was introduced with a Core Duo, but later sold with the Core 2 Duo. They switched to a heat sink with a slightly larger heat pipe and a more powerful fan. Even so, I never had any trouble with upgraded T60s overheating, but I'm sure there was less margin for dust build up, or blocked vents.

 

[Sheep221]

He does not have a turbo on ancient Core duo laptop. Shouldn't be a problem, yet laptops with newer CPUs do have problems going from 35W dual core i5/i7 to 45W quad core.

 

[andy2000]

Also, remember that TDP isn't a measure of how much power the CPU will use, but a spec for how much cooling capacity is required to guarantee that it won't overheat. Notice that all of the socket M Core 2 chips have a 34W TDP. I'll guarantee that the top end T7600 will run hotter than the lower end chips. I'd start with a mid level chip like the T7200.

 

[Phynaz]

Highly unlikely it will work at all.

Core Duo is a 32bit Yonah.
Core 2 Duo is a 64Bit Merom or newer.

 

[jimbob200521]

I'd check the original manufacturer models/specs for your series of laptops. If they came with an option of a C2D or higher end processor, I'd say you'd be good. In general, though, if everything is working right I wouldn't sweat a 4 watt difference in TDP.

 

[SPBHM]

Highly unlikely it will work at all.

Core Duo is a 32bit Yonah.
Core 2 Duo is a 64Bit Merom or newer.

I've upgraded one laptop from Yonah to a t7200 without even needing to ever update the bios, and it all works (but both were 35W as far as I can remember), it really depends on the laptop, but I have the impression that a lot of laptops supported both Core Duo and Core 2 Duo(the ones with FSB 166)

 

[jardows]

I went for a T7200 processor. Just came in the mail today, and the great news is - it works! Now to see if there are any heat problems.