Thinkpads Forum

So, I participate in folding@home, and my laptop is one of the machines I contribute with. After reading around, it looks like I can see a 33% increase in performance in that particular application when swapping a CD T2600 to a C2D T7600. I have been searching for an excuse to pull the trigger on a pricey CPU for this thing anyway so I can consider it to be "maxed out."

The CPU was purchased from eBay. Our computers would want a SL9SD T7600 (mPGA - must have a P, for Pin), but the only one on eBay was $380. That is just too much for me to justify. Well...there is this seller in Hong Kong selling SL9SJ T7600's...the "J" one being a mBGA configuration. Well, this guy must have a good rework lab at his disposal, because he converts the substrate's BGA to a PGA. I saw these months ago and the whole affair seemed far too sketchy. Well, I read through customer reviews on the seller, and many had bought re-pinned C2D chips and there were no complaints. So...for $250US, why not? The chip had a DOA warranty on it.

Well, I received the CPU today & went ahead & installed it. Just for comparison, here are the 2 chips (T2600 left, T7500 right).
http://www.e30tuner.com/other/c2dupgrad ... rade01.jpg

Wow, talk about a die size difference! Now, there have been concerns voiced on here about thermals, particularly because a C2D can dissipate 3W more than a CD CPU. Well, that is not great, but at least the CPU has like 220% more surface area to it. That helps tremendously with heat conduction. I also used some high grade thermal grease (Shin Etsu G751), which will be good for it as well.

Also, here is a shot of the PGA on the substrates. I think that they did a good job reworking the T7600.
http://www.e30tuner.com/other/c2dupgrad ... rade02.jpg

One more update to this...

I used Notebook Hardware Control to undervolt the CPU. This helps with battery life, and thermals. The stock core voltage is 1.1875V. I could maintain a stable system at 1.0625V, but Folding@Home would error out on me at that setting.

Tentatively, Folding@Home is chugging along fine at 1.0875V which is an 7.7% reduction in core voltage. This is a 14.8% decrease in power consumption (100% - (92.3%)^2) since power is related to the square of voltage. This would (theoretically) bring my 34W processor down to 29.0W.

(Actually, the voltages are from NHC...CPU-Z reports a stock voltage of 1.300V, and my current setting is states as being 1.200V. CPU-Z reads it 0.1125V higher than NHC. I am basing my % calculations on CPU-Z's numbers as I feel them to be more conservative)

The T2600 would run at a constant Tcpu of 69-72C in a ~25C room while docked & folding. With the T7600, I am running at 70C right now, 40 minutes into folding while docked. None to shabby, in my opinion.

Congrats on your upgrade. Good to hear the reworked BGA worked for you.

You may want to update your signature

So in general use, ie. not just folding@home, does the performance gain feel like it was worth the price? I have the exact same cpu in my T60p and have been mulling over the C2D upgrade for a while now.

congrats for having the balls to try this!
glad you are the guinea pig for those Hong Kong BGA chips and not me, I also thought it seemed sketchy!

can you show us a screenshot of CPU-Z from this chip?

I still cannot believe those Chinese can solder all those tiny pins on and get them straight!

also.........

did you ever replace your magnesium frame? - a new one is only $27 at lenovo.com, ya know!

all that trouble with the gluing seems a bit nutty to save $27, but maybe I am missing something!

yak wrote:Congrats on your upgrade. Good to hear the reworked BGA worked for you.

You may want to update your signature

Haha...yes good point. Thanks!

Nameless wrote:So in general use, ie. not just folding@home, does the performance gain feel like it was worth the price? I have the exact same cpu in my T60p and have been mulling over the C2D upgrade for a while now.

I have messed around with re-doing some HDR image compilations and it SEEMS faster...but I could be imagining things. It's like when I used to be into modifying cars...after putting in the time & $, it always FELT faster, when most of the mods did squat! F@H shows a DEFINITE 25-50% increase in performance though, so I don't think it is just my imagination.

wild_bill wrote:congrats for having the balls to try this!
glad you are the guinea pig for those Hong Kong BGA chips and not me, I also thought it seemed sketchy!

can you show us a screenshot of CPU-Z from this chip?

I still cannot believe those Chinese can solder all those tiny pins on and get them straight!

also.........

did you ever replace your magnesium frame? - a new one is only $27 at lenovo.com, ya know!

all that trouble with the gluing seems a bit nutty to save $27, but maybe I am missing something!

When I got the chip, I was pretty nervous...but after inspecting it closely, it looked pretty legit. Comparing it to the T2600, it looked very similar. They both look like they just had pins soldered onto the balls. I accidentally bent a couple pins on the new CPU when I was taking pictures, which really made my kick myself..."are these things going to snap off when I straighten them?!" No issues were encountered when straightening them out, so I feel that the folks in whatever factory did this did a decent job. Really, when thinking about it, the only REAL issue here is ESD, not the reworked pins. A pin could snap off & be reattached, and all would be A-OK. PGA or BGA though, ESD will kill the chip.

So, from what I know of sensitive IC's, ESD will kill the chip immediately in most cases, and every now & then it will cause premature failure, but I'd put my money on the chip not working at all right from the start if there was an issue. It only takes one fried transistor out of the tens of millions in there to cause immediate issues.

As for the frame....$27!?!?!?! Well heck, I am ordering one right now!

How difficult is it to replace a T60p CPU?
Just take the old one out, and put new one in?

I have never take apart any laptop before, but I have done the following
- build my own dual CPU desktop 5 - 6 years back, from CPU to heatsink to motherboard to fan to hard drive, so I am no stranger to computer parts
- I removed T60p palm rest and keyboard to blow some dust bunny out. That help with the temperature

I read your heat sink mod. I am a clutz, so anytime I need to apply force to bend something, I start worrying . I wanted to do your heat sink mod (to lower GPU temp), but worry I will break something

@bmwman91: Congratulations on your upgrade! You may even see further performance increase with a 64 bit OS if your apps have native x64 versions (since you now have a x64-capable cpu)

animefans wrote:How difficult is it to replace a T60p CPU?
Just take the old one out, and put new one in?

I have never take apart any laptop before, but I have done the following
- build my own dual CPU desktop 5 - 6 years back, from CPU to heatsink to motherboard to fan to hard drive, so I am no stranger to computer parts
- I removed T60p palm rest and keyboard to blow some dust bunny out. That help with the temperature

I read your heat sink mod. I am a clutz, so anytime I need to apply force to bend something, I start worrying . I wanted to do your heat sink mod (to lower GPU temp), but worry I will break something

I would say that this was not very difficult at all. Just be patient & don't lose any screws (keep them in cups, separated by where they came from). Also, the upper bezel has 3 internal screws under the keyboard...2 black, wide-headed ones, and one really small shiny one. They are on a think steel bracket in the upper middle-left. There are also 2 screws holding it in from the bottom, one IN the rubber foot, and on the other side it is the on on the outside. There are some clips you have to pull/wiggle apart, it feels like you are going to break something, but you won't.

With the lower bezel, keyboard & upper bezel out, you can remove the heat sink (5 screws). Before doing ANY of this, make sure you have some new, good quality thermal grease. Arctic Silver 5 is good and very easy to apply. Shin Etsu G751 is even better thermally, but pricey, only available online & a real pain to apply. I can do a guide for applying that if someone wants. Once you have the HSF removed, the CPU can be pulled by turning the black circular bit 180 degrees CCW. Be gentle!

I recommend using electrical contact cleaner to remove all of the old grease from the CPU & the HSF, or rubbing alcohol if that is not available. Pop in the new CPU and apply some thermal paste to the HSF where it will sit. Don't just shoot a ton of it on there, spread it out into a thin layer, and make sure there are no voids in it. Reinstall the HSF...DON'T FORGET TO PLUG THE FAN IN! I always do, and the computer will beep at me & shut off after a couple seconds...always scares the heck out of me! For an easy, slight improvement in temperatures, you can try bending the 2 tabs on the HS retention clip down a little so they press harder on the HS.

When reassembling it all, make sure that the WWAN / WiFi antenna cables are securely placed & out of the way. The WiFi ones in particular seem to like getting on top of one another, which will cause issues getting the keyboard back in. The tape that is in there does not like to stick again after removal, so it is up to you to tape things back down. Don't use electrical or duct tape...it leaves a horrendous mess.

Marin85 wrote:@bmwman91: Congratulations on your upgrade! You may even see further performance increase with a 64 bit OS if your apps have native x64 versions (since you now have a x64-capable cpu)

Thanks! Yeah, I have thought about running a 64 bit OS. I tried Vista 64 once, but some of my MCAD & programming apps didn't work in it. Eventually I want to go back to Linux, as soon as Wine supports the apps I need (or they are ported...but that isn't something I will hold my breath for!).

Well, I guess you can always go back to Linux x64 and I guess you are certainly already aware of virtualization. Most folks claim that the performance in a widows VM under Linux host is much better then with wine emulation (for all supported applications). I´m yet to find this out...

Marin

EDIT: typo

bmwman91 - Welcome to the club!

I was not aware anyone was doing the BGA to PGA coversion - I heard of this mid 2008, but could not track anyone actually participating in it.

I agree with your ESD statement - Even slight ESD damage could easily destroy a good few transistors, which could lead to shorten life or catastrophic failure.

wild_bill wrote:I still cannot believe those Chinese can solder all those tiny pins on and get them straight!

They don't solder them one by one of course. You take a whole pinboard arranged in the proper layout, and solder it in one-shot using special machinery.

hey bmwman91 -

now you are going to have to order one of these to update your palm rest

wild_bill wrote:hey bmwman91 -

now you are going to have to order one of these to update your palm rest

Haha, I suppose so. I'll keep the original one...a "sleeper" laptop. Not that having one is as fun as a "sleeper" car.....but still.......

dr_st wrote:billThey don't solder them one by one of course. You take a whole pinboard arranged in the proper layout, and solder it in one-shot using special machinery.

Interestingly, the missing pin which has been added to the layout (picture on right) appears to have a different color/appearance solder (more of a silver solder than a gold color). Do you think they re-soldered all of the pins or just added one?

sktn77a wrote:Interestingly, the missing pin which has been added to the layout (picture on right) appears to have a different color/appearance solder (more of a silver solder than a gold color). Do you think they re-soldered all of the pins or just added one?

I took a close look at that. It is just a little left-over solder from the ball that was there as far as I can tell. When I looked closely at the T2600 (left), I could see the pad there as well, but it was covered with solder mask (green stuff). The mBGA package utilizes 479 pins while the mPGA utilizes 478 of the 479. I guess the ones that Intel intends to use pins with get #479 covered up from the start.